Constraining simulation uncertainties in a hydrological model of the Congo River Basin including a combined modelling approach for channel-wetland exchanges
- Authors: Kabuya, Pierre Mulamba
- Date: 2021-04
- Subjects: Congo River Watershed , Watersheds -- Congo (Democratic Republic) , Hydrologic models , Rain and rainfall -- Mathematical models , Runoff -- Mathematical models , Wetland hydrology
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177997 , vital:42897 , 10.21504/10962/177997
- Description: Compared to other large river basins of the world, such as the Amazon, the Congo River Basin appears to be the most ungauged and less studied. This is partly because the basin lacks sufficient observational hydro-climatic monitoring stations and appropriate information on physiographic basin properties at a spatial scale deemed for hydrological applications, making it difficult to estimate water resources at the scale of sub-basins (Chapter 3). In the same time, the basin is facing the challenges related to rapid population growth, uncontrolled urbanisation as well as climate change. Adequate quantification of hydrological processes across different spatial and temporal scales in the basin, and the drivers of change, is essential for prediction and strategic planning to ensure sustainable management of water resources in the Congo River Basin. Hydrological models are particularly important to generate the required information. However, the shortness of the available streamflow records, lack of spatial representativeness of the available streamflow gauging stations and the lack of understanding of the processes in channel-wetland exchanges, are the main challenges that constrain the use of traditional approaches to models development. They also contribute to increased uncertainty in the estimation of water resources across the basin (Chapter 1 and 2). Given this ungauged nature of the Congo River Basin, it is important to resort to hydrological modelling approaches that can reasonably quantify and model the uncertainty associated with water resources estimation (Chapter 4) to make hydrological predictions reliable. This study explores appropriate methods for hydrological predictions and water resources assessment in ungauged catchments of the Congo River Basin. In this context, the core modelling framework combines the quantification of uncertainty in constraint indices, hydrological modelling and hydrodynamic modelling. The latter accounts for channel-wetland exchanges in sub-basins where wetlands exert considerable influence on downstream flow regimes at the monthly time scale. The constraint indices are the characteristics of a sub-basin’s long-term hydrological behaviour and may reflect the dynamics of the different components of the catchment water balance such as climate, water storage and different runoff processes. Currently, six constraint indices namely the mean monthly runoff volume (MMQ in m3 *106), mean monthly groundwater recharge depth (MMR in mm), the 10th, 50th and 90th percentiles of the flow duration curve expressed as a fraction of MMQ (Q10/MMQ, Q50/MMQ, Q90/MMQ) and the percentage of time that zero flows are expected (%Zero), are used in the modelling approach. These were judged to be the minimum number of key indices that can discriminate between different hydrological responses. The constraint indices in the framework help to determine an uncertainty range within which behavioural model parameters of the expected hydrological response can be identified. Predictive equations of the constraint indices across all climate and physiographic regions of the Congo Basin were based only on the aridity index because it was the most influential sub-basin attribute (Chapter 5) for which quantitative information was available. The degree of uncertainty in the constraint Q10/MMQ and Q50/MMQ indices is less than 41%, while it is somewhat higher for the mean monthly runoff (MMQ) and Q90/MMQ constraint indices. The established uncertainty ranges of the constraint indices were tested in some selected sub-basins of the Congo Basin, including the Lualaba (93 sub-basins), Sangha (24 sub-basins), Oubangui (19 sub-basins), Batéké plateaux (4 sub-basins), Kasai (4 sub-basins) and Inkisi (3 sub-basins). The results proved useful through the application of a 2-stage uncertainty approach of the PITMAN model. However, it comes out of this study that the application of the original constraint indices ranges (Chapter 5) generated satisfactory simulation results in some areas, while in others both small and large adjustments were required to fully capture some aspects of the observed hydrological responses (Chapter 6). Part of the reason is attributed to the availability and quality of streamflow data used to develop the constraint indices ranges (Chapter 5). The main issue identified in the modelling process was whether the changes made to the original constraints at headwater-gauged sub-basins can be applied to ungauged upstream sub-basins to match the observed flow at downstream gauging stations. Ideally, only gauged sub-basin’s constraints can be easily revised based on the observed flow. However, the refinement made to gauged sub-basins alone may fail to substantially affect the results if ungauged upstream sub-basins exert a major impact on defining downstream hydrological response. The majority of gauging stations used in this analysis are located downstream of many upstream ungauged sub-basins and therefore adjustments were required in ungauged sub-basins. These adjustments consist of shifting the full range of a constraint index either towards higher or lower values, depending on the degree to which the simulated uncertainty bounds depart from the observed flow. While this modelling approach seems effective in capturing many aspects of the hydrological responses with a reduced level of uncertainty compared to a previous study, it is recommended that the approach be extended to the remaining parts of the Congo Basin and assessed under current and future development conditions including environmental changes. A 2D hydrodynamic river-wetland model (LISFLOOD-FP) has been used to explicitly represent the inundation process exchanges between river channels and wetland systems. The hydrodynamic modelling outputs are used to calibrate the PITMAN wetland sub-model parameters. The five hydrodynamic models constructed for Ankoro, Kamalondo, Kundelungu, Mweru and Tshiangalele wetland systems have been partially validated using independent estimates of inundation extents available from Landsat imagery. Other sources of data such as remote sensing of water level altimetry, SAR images and wetland storage estimates may be used to improve the validation results. However, the important objective in this study was to make sure that flow volume exchanges between river channels and their adjacent floodplains were being simulated realistically. The wetland sub-model parameters are calibrated in a spreadsheet version of the PITMAN wetland routine to achieve visual correspondence between the LISFLOOD-FP and PITMAN wetland sub-model outputs (Storage volumes and channel outputs). The hysteretic patterns of the river-wetland processes were quantified using hysteresis indices and were associated with the spill and return flow parameters of the wetland sub-model and eventually with the wetland morphometric characteristics. One example is the scale parameter of the return flow function (AA), which shows a good relationship with the average surface slope of the wetland when the coefficient parameter (BB) of the same function is kept constant to a value of 1.25. The same parameter (AA) is a good indicator of the wetland emptying mechanism. A small AA indicates a wetland that slowly releases its flow, resulting in a highly delayed and attenuated hydrological response in downstream sub-basins. This understanding has a practical advantage for the estimation of the PITMAN wetland parameters in the many areas where it is not possible, or where the resources are not available, to run complex hydrodynamic models (Chapter 7). The inclusion of these LISFLOOD-FP informed wetland parameters in the basin-scale hydrological modelling results in acceptable simulations for the lower Lualaba drainage system. The small wetlands, like Ankoro and Tshiangalele, have a negligible impact on downstream flow regimes, whereas large wetlands, such as Kamalondo and Mweru, have very large impacts. In general, the testing of the original constraint indices in the region of wetlands and further downstream of the Lualaba drainage system has shown acceptable results. However, there remains an unresolved uncertainty issue related to the under and over-estimation of some aspects of the hydrological response at both Mulongo and Ankoro, two gauging stations in the immediate downstream of the Kamalondo wetland system. It is difficult to attribute this uncertainty to Kamalondo wetland parameters alone because many of the incremental sub-basins contributing to wetland inflows are ungauged. The issue at Mulongo is the under simulation of low flow, while the high flows at the Ankoro gauging station are over-simulated. However, the pattern of the calibrated constraint indices in this region (Chapter 8) shows that the under simulation of low flow at Mulongo cannot be attributed to incremental sub-basins (between Bukama, Kapolowe and Mulongo gauging stations), because their Q90/MMQ constraint indices are even slightly above the original constraint ranges, but maintain a spatial consistency with sub-basins of other regions. Similarly, sub-basins located between Mulongo, Luvua and Ankoro gauging stations have high flow indices slightly below the original constraint ranges and therefore they are unlikely to be responsible for the over simulation of high flow at the Ankoro gauging station. These facts highlight the need for a further understanding of the complex wetland system of Kamalondo. Short-term data collection and monitoring programme are required. Important tributaries that drain to this wetland need to be monitored by installing water level loggers and periodically collecting flow data and river bathymetry. This programme should lead to the development of rating curves of wetland input tributaries. This would partially solve the unresolved uncertainty issues at the Ankoro and Mulongo gauging stations. The integrated modelling approach offers many opportunities in the Congo Basin. The quantified and modelled uncertainty helps to identify regions with high uncertainty and allows for the identification of various data collection and management strategies that can potentially contribute to the uncertainty reduction. The quantified channel-wetland exchanges contribute to the improvement of the overall knowledge of water resources estimation within the regions where the effects of wetlands are evident even at the monthly time scale. In contrast, ignoring uncertainty in the estimates of water resources availability means that water resources planning and management decisions in the Congo Basin will continue to be based on inadequate information and unquantified uncertainty, thus increasing the risk associated with water resources decision making. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Kabuya, Pierre Mulamba
- Date: 2021-04
- Subjects: Congo River Watershed , Watersheds -- Congo (Democratic Republic) , Hydrologic models , Rain and rainfall -- Mathematical models , Runoff -- Mathematical models , Wetland hydrology
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177997 , vital:42897 , 10.21504/10962/177997
- Description: Compared to other large river basins of the world, such as the Amazon, the Congo River Basin appears to be the most ungauged and less studied. This is partly because the basin lacks sufficient observational hydro-climatic monitoring stations and appropriate information on physiographic basin properties at a spatial scale deemed for hydrological applications, making it difficult to estimate water resources at the scale of sub-basins (Chapter 3). In the same time, the basin is facing the challenges related to rapid population growth, uncontrolled urbanisation as well as climate change. Adequate quantification of hydrological processes across different spatial and temporal scales in the basin, and the drivers of change, is essential for prediction and strategic planning to ensure sustainable management of water resources in the Congo River Basin. Hydrological models are particularly important to generate the required information. However, the shortness of the available streamflow records, lack of spatial representativeness of the available streamflow gauging stations and the lack of understanding of the processes in channel-wetland exchanges, are the main challenges that constrain the use of traditional approaches to models development. They also contribute to increased uncertainty in the estimation of water resources across the basin (Chapter 1 and 2). Given this ungauged nature of the Congo River Basin, it is important to resort to hydrological modelling approaches that can reasonably quantify and model the uncertainty associated with water resources estimation (Chapter 4) to make hydrological predictions reliable. This study explores appropriate methods for hydrological predictions and water resources assessment in ungauged catchments of the Congo River Basin. In this context, the core modelling framework combines the quantification of uncertainty in constraint indices, hydrological modelling and hydrodynamic modelling. The latter accounts for channel-wetland exchanges in sub-basins where wetlands exert considerable influence on downstream flow regimes at the monthly time scale. The constraint indices are the characteristics of a sub-basin’s long-term hydrological behaviour and may reflect the dynamics of the different components of the catchment water balance such as climate, water storage and different runoff processes. Currently, six constraint indices namely the mean monthly runoff volume (MMQ in m3 *106), mean monthly groundwater recharge depth (MMR in mm), the 10th, 50th and 90th percentiles of the flow duration curve expressed as a fraction of MMQ (Q10/MMQ, Q50/MMQ, Q90/MMQ) and the percentage of time that zero flows are expected (%Zero), are used in the modelling approach. These were judged to be the minimum number of key indices that can discriminate between different hydrological responses. The constraint indices in the framework help to determine an uncertainty range within which behavioural model parameters of the expected hydrological response can be identified. Predictive equations of the constraint indices across all climate and physiographic regions of the Congo Basin were based only on the aridity index because it was the most influential sub-basin attribute (Chapter 5) for which quantitative information was available. The degree of uncertainty in the constraint Q10/MMQ and Q50/MMQ indices is less than 41%, while it is somewhat higher for the mean monthly runoff (MMQ) and Q90/MMQ constraint indices. The established uncertainty ranges of the constraint indices were tested in some selected sub-basins of the Congo Basin, including the Lualaba (93 sub-basins), Sangha (24 sub-basins), Oubangui (19 sub-basins), Batéké plateaux (4 sub-basins), Kasai (4 sub-basins) and Inkisi (3 sub-basins). The results proved useful through the application of a 2-stage uncertainty approach of the PITMAN model. However, it comes out of this study that the application of the original constraint indices ranges (Chapter 5) generated satisfactory simulation results in some areas, while in others both small and large adjustments were required to fully capture some aspects of the observed hydrological responses (Chapter 6). Part of the reason is attributed to the availability and quality of streamflow data used to develop the constraint indices ranges (Chapter 5). The main issue identified in the modelling process was whether the changes made to the original constraints at headwater-gauged sub-basins can be applied to ungauged upstream sub-basins to match the observed flow at downstream gauging stations. Ideally, only gauged sub-basin’s constraints can be easily revised based on the observed flow. However, the refinement made to gauged sub-basins alone may fail to substantially affect the results if ungauged upstream sub-basins exert a major impact on defining downstream hydrological response. The majority of gauging stations used in this analysis are located downstream of many upstream ungauged sub-basins and therefore adjustments were required in ungauged sub-basins. These adjustments consist of shifting the full range of a constraint index either towards higher or lower values, depending on the degree to which the simulated uncertainty bounds depart from the observed flow. While this modelling approach seems effective in capturing many aspects of the hydrological responses with a reduced level of uncertainty compared to a previous study, it is recommended that the approach be extended to the remaining parts of the Congo Basin and assessed under current and future development conditions including environmental changes. A 2D hydrodynamic river-wetland model (LISFLOOD-FP) has been used to explicitly represent the inundation process exchanges between river channels and wetland systems. The hydrodynamic modelling outputs are used to calibrate the PITMAN wetland sub-model parameters. The five hydrodynamic models constructed for Ankoro, Kamalondo, Kundelungu, Mweru and Tshiangalele wetland systems have been partially validated using independent estimates of inundation extents available from Landsat imagery. Other sources of data such as remote sensing of water level altimetry, SAR images and wetland storage estimates may be used to improve the validation results. However, the important objective in this study was to make sure that flow volume exchanges between river channels and their adjacent floodplains were being simulated realistically. The wetland sub-model parameters are calibrated in a spreadsheet version of the PITMAN wetland routine to achieve visual correspondence between the LISFLOOD-FP and PITMAN wetland sub-model outputs (Storage volumes and channel outputs). The hysteretic patterns of the river-wetland processes were quantified using hysteresis indices and were associated with the spill and return flow parameters of the wetland sub-model and eventually with the wetland morphometric characteristics. One example is the scale parameter of the return flow function (AA), which shows a good relationship with the average surface slope of the wetland when the coefficient parameter (BB) of the same function is kept constant to a value of 1.25. The same parameter (AA) is a good indicator of the wetland emptying mechanism. A small AA indicates a wetland that slowly releases its flow, resulting in a highly delayed and attenuated hydrological response in downstream sub-basins. This understanding has a practical advantage for the estimation of the PITMAN wetland parameters in the many areas where it is not possible, or where the resources are not available, to run complex hydrodynamic models (Chapter 7). The inclusion of these LISFLOOD-FP informed wetland parameters in the basin-scale hydrological modelling results in acceptable simulations for the lower Lualaba drainage system. The small wetlands, like Ankoro and Tshiangalele, have a negligible impact on downstream flow regimes, whereas large wetlands, such as Kamalondo and Mweru, have very large impacts. In general, the testing of the original constraint indices in the region of wetlands and further downstream of the Lualaba drainage system has shown acceptable results. However, there remains an unresolved uncertainty issue related to the under and over-estimation of some aspects of the hydrological response at both Mulongo and Ankoro, two gauging stations in the immediate downstream of the Kamalondo wetland system. It is difficult to attribute this uncertainty to Kamalondo wetland parameters alone because many of the incremental sub-basins contributing to wetland inflows are ungauged. The issue at Mulongo is the under simulation of low flow, while the high flows at the Ankoro gauging station are over-simulated. However, the pattern of the calibrated constraint indices in this region (Chapter 8) shows that the under simulation of low flow at Mulongo cannot be attributed to incremental sub-basins (between Bukama, Kapolowe and Mulongo gauging stations), because their Q90/MMQ constraint indices are even slightly above the original constraint ranges, but maintain a spatial consistency with sub-basins of other regions. Similarly, sub-basins located between Mulongo, Luvua and Ankoro gauging stations have high flow indices slightly below the original constraint ranges and therefore they are unlikely to be responsible for the over simulation of high flow at the Ankoro gauging station. These facts highlight the need for a further understanding of the complex wetland system of Kamalondo. Short-term data collection and monitoring programme are required. Important tributaries that drain to this wetland need to be monitored by installing water level loggers and periodically collecting flow data and river bathymetry. This programme should lead to the development of rating curves of wetland input tributaries. This would partially solve the unresolved uncertainty issues at the Ankoro and Mulongo gauging stations. The integrated modelling approach offers many opportunities in the Congo Basin. The quantified and modelled uncertainty helps to identify regions with high uncertainty and allows for the identification of various data collection and management strategies that can potentially contribute to the uncertainty reduction. The quantified channel-wetland exchanges contribute to the improvement of the overall knowledge of water resources estimation within the regions where the effects of wetlands are evident even at the monthly time scale. In contrast, ignoring uncertainty in the estimates of water resources availability means that water resources planning and management decisions in the Congo Basin will continue to be based on inadequate information and unquantified uncertainty, thus increasing the risk associated with water resources decision making. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2021
- Full Text:
- Date Issued: 2021-04
Evaluation of water quality, selected metals and endocrine-disrupting compounds in the rivers and municipal wastewaters of Eastern Cape province, South Africa
- Authors: Farounbi, Adebayo Ibikunle
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177327 , vital:42810
- Description: Thesis embargoed. Release date April 2022. , Thesis (PhD) -- Faculty of Science, Institute of Water Research, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Farounbi, Adebayo Ibikunle
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177327 , vital:42810
- Description: Thesis embargoed. Release date April 2022. , Thesis (PhD) -- Faculty of Science, Institute of Water Research, 2021
- Full Text:
- Date Issued: 2021-04
Exploring learners’ proficiency in stoichiometry and attitudes towards science through Process Oriented Guided Inquiry Learning (POGIL) intervention
- Authors: Agunbiade, Arinola Esther
- Date: 2021-04
- Subjects: Stoichiometry -- Study and teaching (Secondary) -- Nigeria , Chemistry -- Study and teaching (Secondary) -- Nigeria , Process-oriented guided inquiry learning , Student-centered learning -- Nigeria , Science students -- Attitudes
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/174402 , vital:42474
- Description: Stoichiometry is one of the difficult topics in the senior secondary school chemistry curriculum. It is usually taught through the traditional lecture method of presentation that is non-engaging for learners. Consequently, there is poor understanding, achievement, and negative perceptions of stoichiometry and chemistry in general. The goal of this study was to explore learners’ evolving proficiency in stoichiometry and attitudes towards science as a result of their participation in Process Oriented Guided Inquiry Learning (POGIL) activities. That is, POGIL which incorporates guided-inquiry and collaborative learning was introduced as an intervention strategy in learning stoichiometry. This was assessed by examining learners’ experiences with learning stoichiometry before and after the POGIL intervention. The study further investigated possible contributing factors to learners’ evolving proficiency in stoichiometry and attitudes towards science. This study employed the socio-cultural learning theory as proposed by Vygotsky (1978). The role of socio-cultural features such as ‘social interaction’, ‘cultural tools’, ‘self-regulation’ and ‘zone of proximal development’ (ZPD) were explored with regards to learners’ stoichiometry proficiency and attitudes towards science progression as they participated in POGIL activities. The work of Kilpatrick, Swafford and Findell (2001) on proficiency and Fraser (1981) on attitudes towards science were used as analytical lenses to understand learners’ proficiency in stoichiometry and attitudes towards science, respectively. This study was underpinned by the pragmatic research paradigm. Thus, a Quant + Qual concurrent mixed-methods approach which involves generating, analysing, and integrating both qualitative and quantitative data to provide answers to research questions was adopted. It was an intervention study carried out in two senior secondary schools in the Ilorin metropolis of Kwara State, Nigeria. A sample of 53 senior secondary school year two learners participated. Questionnaires and journal entries were completed by the 53 learners, while seven learners were interviewed. Data were collected using both qualitative and quantitative data generating tools including pre-and post-tests. The stoichiometry learning questionnaire (SLQ), test of science related attitude (TOSRA) questionnaire, and stoichiometry achievement tool (SAT) were used to generate quantitative data while the SLQ, semi-structured interviews, and journal entries were the qualitative data tools. Data were generated in three phases. Phase one was baseline data through SLQ, TOSRA and SAT pre-tests. The second phase was the intervention phase where the POGIL approach was implemented in the classrooms and learners were engaged in journal entries. Post-intervention was the last phase where TOSRA and SAT post-tests were administered and semi-structured interviews were conducted with participants. Thus, data were analysed quantitatively and qualitatively. Before the POGIL intervention, the findings of this study revealed that most of the learners perceived stoichiometry as difficult because of the instructional characteristics, the nature of stoichiometry concepts, and learners’ attributes. After the POGIL intervention, however, learners showed increased proficiency in stoichiometry and attitudes towards science. Findings also indicate that learners’ proficiency in stoichiometry and attitude towards science were associated with the facilitators or learning environment features, the nature of instructional characteristics, learners’ perceptions of stoichiometry or science, and the extent to which learners could comprehend or master science concepts. Notably, these features are intertwined and cohere with the socio-cultural theory and POGIL principles. This study offered insights into how proficiency in stoichiometry and attitudes towards science may develop among senior secondary school learners in Nigeria. The findings point to POGIL as an example of an instructional approach that provides enabling characteristics and useful information for planning instructional activities for the development and nurturing of proficiency and attitudes towards science. The results suggest that the POGIL strategy could alleviate some of the factors perceived as contributors to difficulty in learning stoichiometry. As such, the study makes contributions to the field of science education in Nigeria particularly regarding how both the tenets of the socio-cultural framework (social interaction, cultural tools, self-regulation, and ZPD) and POGIL (guided-inquiry and collaborative learning) could be aligned to facilitate the development of proficiency and attitudes towards science. The study, therefore, recommends that POGIL should be used as an inquiry-based approach in science classrooms to promote the development of learners’ proficiency and attitudes towards science. The study could also be utilised as a resource to guide or set a base for further investigation into the implementation of POGIL in other areas of chemistry or science as well as creating professional development spaces that promote community of practice among science teachers as observed in this study.
- Full Text:
- Date Issued: 2021-04
- Authors: Agunbiade, Arinola Esther
- Date: 2021-04
- Subjects: Stoichiometry -- Study and teaching (Secondary) -- Nigeria , Chemistry -- Study and teaching (Secondary) -- Nigeria , Process-oriented guided inquiry learning , Student-centered learning -- Nigeria , Science students -- Attitudes
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/174402 , vital:42474
- Description: Stoichiometry is one of the difficult topics in the senior secondary school chemistry curriculum. It is usually taught through the traditional lecture method of presentation that is non-engaging for learners. Consequently, there is poor understanding, achievement, and negative perceptions of stoichiometry and chemistry in general. The goal of this study was to explore learners’ evolving proficiency in stoichiometry and attitudes towards science as a result of their participation in Process Oriented Guided Inquiry Learning (POGIL) activities. That is, POGIL which incorporates guided-inquiry and collaborative learning was introduced as an intervention strategy in learning stoichiometry. This was assessed by examining learners’ experiences with learning stoichiometry before and after the POGIL intervention. The study further investigated possible contributing factors to learners’ evolving proficiency in stoichiometry and attitudes towards science. This study employed the socio-cultural learning theory as proposed by Vygotsky (1978). The role of socio-cultural features such as ‘social interaction’, ‘cultural tools’, ‘self-regulation’ and ‘zone of proximal development’ (ZPD) were explored with regards to learners’ stoichiometry proficiency and attitudes towards science progression as they participated in POGIL activities. The work of Kilpatrick, Swafford and Findell (2001) on proficiency and Fraser (1981) on attitudes towards science were used as analytical lenses to understand learners’ proficiency in stoichiometry and attitudes towards science, respectively. This study was underpinned by the pragmatic research paradigm. Thus, a Quant + Qual concurrent mixed-methods approach which involves generating, analysing, and integrating both qualitative and quantitative data to provide answers to research questions was adopted. It was an intervention study carried out in two senior secondary schools in the Ilorin metropolis of Kwara State, Nigeria. A sample of 53 senior secondary school year two learners participated. Questionnaires and journal entries were completed by the 53 learners, while seven learners were interviewed. Data were collected using both qualitative and quantitative data generating tools including pre-and post-tests. The stoichiometry learning questionnaire (SLQ), test of science related attitude (TOSRA) questionnaire, and stoichiometry achievement tool (SAT) were used to generate quantitative data while the SLQ, semi-structured interviews, and journal entries were the qualitative data tools. Data were generated in three phases. Phase one was baseline data through SLQ, TOSRA and SAT pre-tests. The second phase was the intervention phase where the POGIL approach was implemented in the classrooms and learners were engaged in journal entries. Post-intervention was the last phase where TOSRA and SAT post-tests were administered and semi-structured interviews were conducted with participants. Thus, data were analysed quantitatively and qualitatively. Before the POGIL intervention, the findings of this study revealed that most of the learners perceived stoichiometry as difficult because of the instructional characteristics, the nature of stoichiometry concepts, and learners’ attributes. After the POGIL intervention, however, learners showed increased proficiency in stoichiometry and attitudes towards science. Findings also indicate that learners’ proficiency in stoichiometry and attitude towards science were associated with the facilitators or learning environment features, the nature of instructional characteristics, learners’ perceptions of stoichiometry or science, and the extent to which learners could comprehend or master science concepts. Notably, these features are intertwined and cohere with the socio-cultural theory and POGIL principles. This study offered insights into how proficiency in stoichiometry and attitudes towards science may develop among senior secondary school learners in Nigeria. The findings point to POGIL as an example of an instructional approach that provides enabling characteristics and useful information for planning instructional activities for the development and nurturing of proficiency and attitudes towards science. The results suggest that the POGIL strategy could alleviate some of the factors perceived as contributors to difficulty in learning stoichiometry. As such, the study makes contributions to the field of science education in Nigeria particularly regarding how both the tenets of the socio-cultural framework (social interaction, cultural tools, self-regulation, and ZPD) and POGIL (guided-inquiry and collaborative learning) could be aligned to facilitate the development of proficiency and attitudes towards science. The study, therefore, recommends that POGIL should be used as an inquiry-based approach in science classrooms to promote the development of learners’ proficiency and attitudes towards science. The study could also be utilised as a resource to guide or set a base for further investigation into the implementation of POGIL in other areas of chemistry or science as well as creating professional development spaces that promote community of practice among science teachers as observed in this study.
- Full Text:
- Date Issued: 2021-04
Exploring Social Learning within the Context of Community-Based Farming : Implications for Farmers’ Agency and Capabilities
- Authors: Dirwai, Crispen
- Date: 2021-04
- Subjects: Crops and climate -- Zimbabwe -- Mutasa District , Livestock -- Climatic factors -- Zimbabwe -- Mutasa District , Social learning -- Zimbabwe -- Mutasa District , Community-supported agriculture -- Zimbabwe -- Mutasa District , Environmental education -- Zimbabwe -- Mutasa District , Climatic changes -- Social aspects -- Zimbabwe -- Mutasa District , Critical realism
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/174526 , vital:42485 , https://doi.org/10.21504/10962/174526
- Description: This thesis, ‘Exploring social learning within the context of community-based farming: Implications for farmers’ agency and capabilities’, provided an opportunity to investigate how community-based farmers engaged a social learning process in adjusting their practices to the observed climate change and variability risks and vulnerabilities. The social learning and pedagogic trajectory towards climate change adaptation, involved a multi-sectoral approach in a community of practice that was inclusive of extension service, developmental agencies, a university, climate change activists, a primary school, a university, the agro-industrial community, the urban open market and the local standards association. Social learning, in this community of practice, took place during field days, field tours, focus groups and observations in a multi-case study approach. The main research question addressed in this thesis was ‘How can and does social learning facilitate or constrain the conversion of resources into functionings and new adaptation capabilities of communal farmers in Muchena village in the face of increasing climate change and associated climate variability related socio-ecological risks and vulnerabilities?’ In order to address this main research question and its corresponding sub-questions, two main categories of climate change adaptive agricultural practices, crop and non-crop, were studied in the context of social learning and collective and individual capabilities and agency. The research ontology and epistemology were grounded in critical realism, with the epistemic work in the multiple case study being drawing on a constructivist approach where eleven Farmers’ Case Stories [FCS] from crop and non-crop community-based farmers were purposively followed throughout this thesis journey, while the ontological dynamics were pursued through critical realist depth ontological enquiry. The theoretical framework for this thesis encompassed Bhaskar’s (1998; 2016) dialectical critical realist MELD schema, which underlabours conversion factors from Sen’s (1993; 2005) capabilities theory mobilised via the six sequential moments of the pedagogic practice of social learning as articulated by Wals (2007). This gave the theoretical framework a multi-dimensional facet. In this multi-dimensional theoretical framework, the ontologically influential generative mechanisms identified at 1M, were droughts, food insecurity, economic poverty, poor farming methods, floods, pests, socio-political stress, socio-cultural and intergenerational knowledge transfer, government policies and market forces. Effort was made to absent these ills at 2E, through knowledge co-creation within the communities of practice, through individual and collective reflexivity and was guided by the six sequential moments of Wals’ (2007) social learning pedagogic trajectory and by the three capabilities conversion factors; personal, environmental and social. At 3L’s totalities (laminated) and false totalities and compromises, the community-based farmers came to realise, appreciate and utilised the benefits of individual and collective agency as knowledge generation. In the theoretical framework, the social learning process was a product of collective and individual agency, a product of co-creation, co-sharing and co-monitoring and mentoring of each other’s work in a non-linear process towards transformation at 4D. The thesis identified the following capability sets and their corresponding functionings: education with the new achieved functionings of knowledge on market oriented economy with more functionings such as apiary, dendrology, aqua-culture and horticultural practices, partnerships including contract farming and company registration; health as a capability set had the new functionings of improved people’s and soil’s health from organic and conservation production practices; nutrition as a capability set with new functionings of organic and conservation farming as well as, through testing of products and soils to ascertain nutritional parameters, nutritional functionings. These identified capability sets as valued beings and doings all attempted to absent climate change induced droughts, food insecurity and economic poverty through the social learning process. The new achieved functionings of knowledge on related market oriented economy, were used for food security as farmers were able to buy maize, the staple food, which has been constrained by climate change induced droughts and pests. The new capability sets and achieved functionings in alternatives to maize crop farming could be viewed in this thesis as a positive emancipatory cyclic movement in the community-based farmers from non-being to agency [1M to 4D]. The thesis found that for the social learning process to be transformative, the community-based farmers had to reflect as individuals and collectively as a community from T1 [social learning layer 1] to T00 [social learning as multi-layered and infinite]. Learning starts from T1 by engaging the ontological and epistemological question ‘what?’ and the pedagogical question, ‘how?’, in order to understand existing ills and how best to absent them. Tensions existed as the community still take maize meal as their staple food and yet maize production is less resilient to droughts in the absence of water harvesting for irrigation. Despite realising the nutritional value of small grains, the research findings claimed that small grains were difficult to process into a mealie-meal and so, could not replace maize as a staple food. Theoretical contributions from this thesis entailed both epistemological and ontological implications as the community-based farmers started to question positivism as the only benchmark for organic standards by sending what they self-perceived as ‘organic’ products and soils, for verification from observed laboratory tests. This might have indicated a recognised shift in the epistemology of the poor community-based farmer, who are widely viewed in literature, as non-being and subsistence, towards an organised transformative market oriented practice. In this regard, transformative social learning catalysed by the thesis, contributed towards an organic practice characterised by absenting synthetic fertilisers and certain heavy elements from the soils and from the products, thereby adapting and mitigating to global climate change at a micro-scale. The study, though small scale, might be viewed as having global policy implications. For SGD:2 FCS 1, VS absented hunger by transforming from zero tonnage in 2012 to an estimated harvest of four tonnes in 2017. For SDG:3, FCS 3, LN produced close to a tonne of organic peas that passed through laboratory testing for nutritional parameters and testing against heavy metals during the 2018 and 2019 farming season. SDG: 1 could be assessed and reflected through improved livelihoods from income raised under market gardening as shown in FCS 3, LN; FCS, 4 SM2; FCS 5 SS and FCS 6 JM2. Also from SDG 1, were alternatives to maize crop farming and climate change adaptation market oriented apiary practiced by FCS 7, LM2 & FCS 8, LM3 and market oriented dendrology from FCS, 10, VC & FCS 11, JC. FCS 10, VC, managed to register a small company while FCS 11, JC managed to get contracts from reputable tobacco companies in the country and he also managed to access bank loans to purchase a small truck to absent the transport ills that constrained the youths who finally moved out of the achieved functioning of dendrology. FCS, 3, LN and the group of youths valued sending their products and soils for laboratory tests, an indicator of the quality of education that they attained through Social learning process’ communities of practice engagement. By supplying part of their products as raw materials to an agro-industry, the newly achieved functioning of market oriented agriculture from FCS 3, LN and FCS 4, SM2 could be viewed as a move towards SDG: 9. In terms of SDG: 12, the farming practices studied in this thesis were deemed environmentally friendly, green and so were adaptations to climate change which could be read along with SDG: 13. The thesis findings thus could be viewed as those that could open up some ways of assessing and providing practical implementation pathways for some of the sustainable development goals as well as providing a platform to interrogate other ways of understanding critical realism’s underlying generative mechanisms as enablers and constrainers to shaping social learning and people’s measurable functionings in the context of education for sustainable development and the global action programme (GAP) and its immanent successor, the ESD Agenda 2030 framework. The research is therefore well poised to inform this agenda. The study concludes that in order to enhance community-based farmers’ social learning and agency towards climate change adaptation, extension service, the standards association institution, agro-industry, the university as well as the media, might need to engage pro-actively with the farmers’ capabilities and agency. The thesis also attempted to inform the university institution’s community engagement, thereby giving practical meaning to the whole institution approaches to ESD as promoted in the UNESCO ESD Global Action Programme, and the emerging ESD 2030 Agenda. The thesis therefore has potential to inform pedagogic practices at the formal, non-formal and the informal learning sectors. The thesis concludes that the social learning process, when coupled with critical realism and the capabilities theories, could facilitate the conversion of resources into new adaptive functionings. The social learning process is transformative, reflexive and recursive, but might have to start from 1M to 4D and from T1 to T00. Moreover, the thesis concludes that poverty remained one of the major disablers of the farmers’ capabilities and agency in this thesis. , Thesis (PhD)--Rhodes University, Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Dirwai, Crispen
- Date: 2021-04
- Subjects: Crops and climate -- Zimbabwe -- Mutasa District , Livestock -- Climatic factors -- Zimbabwe -- Mutasa District , Social learning -- Zimbabwe -- Mutasa District , Community-supported agriculture -- Zimbabwe -- Mutasa District , Environmental education -- Zimbabwe -- Mutasa District , Climatic changes -- Social aspects -- Zimbabwe -- Mutasa District , Critical realism
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/174526 , vital:42485 , https://doi.org/10.21504/10962/174526
- Description: This thesis, ‘Exploring social learning within the context of community-based farming: Implications for farmers’ agency and capabilities’, provided an opportunity to investigate how community-based farmers engaged a social learning process in adjusting their practices to the observed climate change and variability risks and vulnerabilities. The social learning and pedagogic trajectory towards climate change adaptation, involved a multi-sectoral approach in a community of practice that was inclusive of extension service, developmental agencies, a university, climate change activists, a primary school, a university, the agro-industrial community, the urban open market and the local standards association. Social learning, in this community of practice, took place during field days, field tours, focus groups and observations in a multi-case study approach. The main research question addressed in this thesis was ‘How can and does social learning facilitate or constrain the conversion of resources into functionings and new adaptation capabilities of communal farmers in Muchena village in the face of increasing climate change and associated climate variability related socio-ecological risks and vulnerabilities?’ In order to address this main research question and its corresponding sub-questions, two main categories of climate change adaptive agricultural practices, crop and non-crop, were studied in the context of social learning and collective and individual capabilities and agency. The research ontology and epistemology were grounded in critical realism, with the epistemic work in the multiple case study being drawing on a constructivist approach where eleven Farmers’ Case Stories [FCS] from crop and non-crop community-based farmers were purposively followed throughout this thesis journey, while the ontological dynamics were pursued through critical realist depth ontological enquiry. The theoretical framework for this thesis encompassed Bhaskar’s (1998; 2016) dialectical critical realist MELD schema, which underlabours conversion factors from Sen’s (1993; 2005) capabilities theory mobilised via the six sequential moments of the pedagogic practice of social learning as articulated by Wals (2007). This gave the theoretical framework a multi-dimensional facet. In this multi-dimensional theoretical framework, the ontologically influential generative mechanisms identified at 1M, were droughts, food insecurity, economic poverty, poor farming methods, floods, pests, socio-political stress, socio-cultural and intergenerational knowledge transfer, government policies and market forces. Effort was made to absent these ills at 2E, through knowledge co-creation within the communities of practice, through individual and collective reflexivity and was guided by the six sequential moments of Wals’ (2007) social learning pedagogic trajectory and by the three capabilities conversion factors; personal, environmental and social. At 3L’s totalities (laminated) and false totalities and compromises, the community-based farmers came to realise, appreciate and utilised the benefits of individual and collective agency as knowledge generation. In the theoretical framework, the social learning process was a product of collective and individual agency, a product of co-creation, co-sharing and co-monitoring and mentoring of each other’s work in a non-linear process towards transformation at 4D. The thesis identified the following capability sets and their corresponding functionings: education with the new achieved functionings of knowledge on market oriented economy with more functionings such as apiary, dendrology, aqua-culture and horticultural practices, partnerships including contract farming and company registration; health as a capability set had the new functionings of improved people’s and soil’s health from organic and conservation production practices; nutrition as a capability set with new functionings of organic and conservation farming as well as, through testing of products and soils to ascertain nutritional parameters, nutritional functionings. These identified capability sets as valued beings and doings all attempted to absent climate change induced droughts, food insecurity and economic poverty through the social learning process. The new achieved functionings of knowledge on related market oriented economy, were used for food security as farmers were able to buy maize, the staple food, which has been constrained by climate change induced droughts and pests. The new capability sets and achieved functionings in alternatives to maize crop farming could be viewed in this thesis as a positive emancipatory cyclic movement in the community-based farmers from non-being to agency [1M to 4D]. The thesis found that for the social learning process to be transformative, the community-based farmers had to reflect as individuals and collectively as a community from T1 [social learning layer 1] to T00 [social learning as multi-layered and infinite]. Learning starts from T1 by engaging the ontological and epistemological question ‘what?’ and the pedagogical question, ‘how?’, in order to understand existing ills and how best to absent them. Tensions existed as the community still take maize meal as their staple food and yet maize production is less resilient to droughts in the absence of water harvesting for irrigation. Despite realising the nutritional value of small grains, the research findings claimed that small grains were difficult to process into a mealie-meal and so, could not replace maize as a staple food. Theoretical contributions from this thesis entailed both epistemological and ontological implications as the community-based farmers started to question positivism as the only benchmark for organic standards by sending what they self-perceived as ‘organic’ products and soils, for verification from observed laboratory tests. This might have indicated a recognised shift in the epistemology of the poor community-based farmer, who are widely viewed in literature, as non-being and subsistence, towards an organised transformative market oriented practice. In this regard, transformative social learning catalysed by the thesis, contributed towards an organic practice characterised by absenting synthetic fertilisers and certain heavy elements from the soils and from the products, thereby adapting and mitigating to global climate change at a micro-scale. The study, though small scale, might be viewed as having global policy implications. For SGD:2 FCS 1, VS absented hunger by transforming from zero tonnage in 2012 to an estimated harvest of four tonnes in 2017. For SDG:3, FCS 3, LN produced close to a tonne of organic peas that passed through laboratory testing for nutritional parameters and testing against heavy metals during the 2018 and 2019 farming season. SDG: 1 could be assessed and reflected through improved livelihoods from income raised under market gardening as shown in FCS 3, LN; FCS, 4 SM2; FCS 5 SS and FCS 6 JM2. Also from SDG 1, were alternatives to maize crop farming and climate change adaptation market oriented apiary practiced by FCS 7, LM2 & FCS 8, LM3 and market oriented dendrology from FCS, 10, VC & FCS 11, JC. FCS 10, VC, managed to register a small company while FCS 11, JC managed to get contracts from reputable tobacco companies in the country and he also managed to access bank loans to purchase a small truck to absent the transport ills that constrained the youths who finally moved out of the achieved functioning of dendrology. FCS, 3, LN and the group of youths valued sending their products and soils for laboratory tests, an indicator of the quality of education that they attained through Social learning process’ communities of practice engagement. By supplying part of their products as raw materials to an agro-industry, the newly achieved functioning of market oriented agriculture from FCS 3, LN and FCS 4, SM2 could be viewed as a move towards SDG: 9. In terms of SDG: 12, the farming practices studied in this thesis were deemed environmentally friendly, green and so were adaptations to climate change which could be read along with SDG: 13. The thesis findings thus could be viewed as those that could open up some ways of assessing and providing practical implementation pathways for some of the sustainable development goals as well as providing a platform to interrogate other ways of understanding critical realism’s underlying generative mechanisms as enablers and constrainers to shaping social learning and people’s measurable functionings in the context of education for sustainable development and the global action programme (GAP) and its immanent successor, the ESD Agenda 2030 framework. The research is therefore well poised to inform this agenda. The study concludes that in order to enhance community-based farmers’ social learning and agency towards climate change adaptation, extension service, the standards association institution, agro-industry, the university as well as the media, might need to engage pro-actively with the farmers’ capabilities and agency. The thesis also attempted to inform the university institution’s community engagement, thereby giving practical meaning to the whole institution approaches to ESD as promoted in the UNESCO ESD Global Action Programme, and the emerging ESD 2030 Agenda. The thesis therefore has potential to inform pedagogic practices at the formal, non-formal and the informal learning sectors. The thesis concludes that the social learning process, when coupled with critical realism and the capabilities theories, could facilitate the conversion of resources into new adaptive functionings. The social learning process is transformative, reflexive and recursive, but might have to start from 1M to 4D and from T1 to T00. Moreover, the thesis concludes that poverty remained one of the major disablers of the farmers’ capabilities and agency in this thesis. , Thesis (PhD)--Rhodes University, Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-04
Indigenous knowledge of ecosystem services in rural communities of the Eastern Cape, South Africa
- Authors: Murata, Chenai
- Date: 2021-04
- Subjects: Ethnoscience -- South Africa -- Eastern Cape , Ecosystem management -- South Africa -- Eastern Cape , Nature -- Effect of human beings on -- South Africa -- Eastern Cape , Human ecology -- South Africa -- Eastern Cape , Human beings -- Effect of environment on -- South Africa -- Eastern Cape , South Africa -- Eastern Cape -- Rural conditions
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177929 , vital:42891 , 10.21504/10962/177929
- Description: This thesis is on indigenous knowledge of ecosystem services. The ecosystem service framework and its associated concepts are fairly young, having been introduced in the ecological discipline in the 1980s. The ecosystem service framework posits that the wellbeing of humans and their communities is dependent on services supplied by ecosystems. It emphasises that for the ecosystems to be able to supply the services, they need to be in a well-functioning state. This idea of well-functioning is predicated on the argument that the ecosystem service framework enjoins resource users to exercise responsible stewardship to prevent degradation and overharvesting. Moreover, the concept of dependence suggests that ecosystem services are of value to humans. The dominant means of measuring the value of ecosystem services has been the economic valuation method in which the contribution that each service makes to human wellbeing is quantified into monetary units. The framework disaggregates the services into four groups, namely provisioning, cultural, supporting and regulatory and seeks to all the pillars of human wellbeing including health, subsistence and spirituality into each of these groups. In doing all this, the framework significantly reconfigures the way we look at and present human-nature relations. This change has the potential to influence significant shifts in how ecological research and intervention programmes are conducted in the foreseeable future. However, the reality that the ecosystem service framework was formulated within, and is informed by the scientific epistemology begs the question: what do traditional rural communities who depend mainly on indigenous knowledge systems (IKS) for shaping and interoperating their relations with nature know of the ecosystem service concept? Rural communities are the ones who interact directly with nature on a day-to-day basis. This makes them a very critical component in the ecosystem service framework. Although South Africa has had studies in the ecosystem service theme, little has been done to attempt to investigate and document indigenous knowledge of ecosystem services that rural communities possess. By focusing only on scientific knowledge of ecosystem services, the South African literature does not do justice to the plural epistemologies of the ecosystem service users in the country. More importantly, the continued dearth of public information on indigenous knowledge of ecosystem services can potentially obstruct implementation of locally sensitive intervention programmes because nothing is known about how the local communities conceptualise the ecosystem service framework. All this presents a crucial gap in the South African research; one that unless effort is made to contribute towards filling it, our knowledge of how communities experience the ecosystem service framework in South Africa will remain skewed. This study set out to investigate and document indigenous knowledge of ecosystem services in order to contribute towards filling this gap. Indigenous knowledge system is an umbrella epistemic system that includes lay ecological knowledge (LEK), traditional ecological knowledge (TEK) and many other related organized systems of knowing. Although the thesis has a chapter on LEK, its primary focus was TEK because the thesis was interested in unravelling how aspects of tradition including taboos, customs, traditional rules and belief in ancestral forces influence local communities’ knowledge of some key aspects of the ecosystem service framework including knowledge of various ecosystem services, valuation of ecosystem services, management of ecosystem services and perceptions of the management practices. The decision to focus on TEK was based on the reasoning that rural communities of the Eastern Cape boast a strong reputation of being traditional, recognizing ancestral spirits, legends and taboos as critical tools of knowledge generation and transmission. Using both mixed methods in some chapters and the qualitative approach alone in others, the study collected data in five villages of Mgwalana, Mahlungulu, Colana, Gogela and Nozitshena located in the north eastern part of Eastern Cape Province of South Africa, a region formerly called Transkei. The data were collected not on ecosystem services; but on the local people’s knowledge of ecosystem services. Although literature was consulted, the study regarded respondents as the primary source of data, hence the findings and conclusions presented in this thesis are about what local people know about ecosystem services. The study uses critical realist theoretical lenses to interpret respondents’ reports. The lenses included the principle of the separation between ontology and epistemology, the iceberg metaphor of ontology, epistemological pluralism and the hermeneutic dimension. These lenses were used to make sense of both the knowledge system of local people and the things about which their knowledge was. As part of discussing the local people’s knowledge, the study sometimes refers to science. This is not because I expected them to demonstrate knowledge similar to science. Instead, it was a critical realist dialectical way of explaining what something is by demonstrating what it is not. The study made a couple of key findings that can potentially enhance the growth of the South African ecosystem service discipline. First, respondents demonstrated knowledge of ecosystem services by mentioning a range of them such as drinking water, medicinal plants, cultural plants and fuelwood and how they affect the wellbeing of humans. However, what they did not have good knowledge of is that nature services can be classified into the four groups of supporting, regulatory, cultural and provisioning. Among the four ecosystem services groups, respondents could identify two only; provisional and cultural. Second, local communities depend heavily on ecosystem services for their well-being. The services include fuelwood, construction timber, medicinal plants, wild fruits, wild fish, cultural services and thatch grass. Although they appreciate that ecosystem services have value to their wellbeing, local people found it difficult to represent the value in monetary units. The conditions that make it difficult for local people to perceive ecosystem services as commodities include the absence of well-defined property system, lack of a quantitative consumer tradition and absence of an economic conception of nature. Third, local people understand the need to keep ecosystems in a well-functioning state hence they implement several traditional practices to manage ecosystem services. These practices include taboos, designating certain resources as sacred, legends, customary law, as well as some secular practices including gelesha and stone terracing. However, it is not easy to understand how traditional management practices work because they are not empirically observable. Fourth, local people possess knowledge of the reality that if not well managed, ecosystems can undergo degradation and hence fail to supply the services needed for human wellbeing. However, they explain the causes of degradation in terms of changes observable at the empirical level and the invisible causal power of supernatural forces. The inclusion of natural forces in degradation explanations marks a departure from the scientific explanations that revolve around biophysical processes. Fifth, the use of traditional management practices such as taboos to management ecosystems is under threat at the local communities. The threat can be attributed to three groups of causes, namely changes in worldviews due to adoption of formal education and Christianity, institutional disharmony playing out between the state and local traditional leadership, and lifestyle changes. These challenges constrain the opportunity for local people to apply traditional management practices to prevent the degradation of ecosystems. The net implication of this is that it renders it difficult for researchers and policy makers to assess the effectiveness of traditional management practices because they are not being implemented in full. In light of all these findings, the thesis concludes that TEK is underlabouring for the ecosystem service framework in the sense that it is used by local communities to generate knowledge of ecological concepts and phenomena. This means that TEK does not exist for the sake of its own self. Drawing from this finding, the study proposes a framework of analysing TEK as an underlabourer for social-ecological triggers or issues. Nonetheless, there are few factors that can be sources of limitation to the study. These include the reality that it was difficult to access pure traditional knowledge because over the years the local communities have received many state-sponsored ecological intervention programmes and a possible personal bias given the reality that I grew up in a traditional household and my father was a key holder or TEK. , Thesis (PhD) -- Faculty of Science, Environmental Science, 2021 , Thesis chapter to be published in 'Green and Low-Carbon Economy'. Journal available: https://ojs.bonviewpress.com/index.php/GLCE/index
- Full Text:
- Date Issued: 2021-04
- Authors: Murata, Chenai
- Date: 2021-04
- Subjects: Ethnoscience -- South Africa -- Eastern Cape , Ecosystem management -- South Africa -- Eastern Cape , Nature -- Effect of human beings on -- South Africa -- Eastern Cape , Human ecology -- South Africa -- Eastern Cape , Human beings -- Effect of environment on -- South Africa -- Eastern Cape , South Africa -- Eastern Cape -- Rural conditions
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177929 , vital:42891 , 10.21504/10962/177929
- Description: This thesis is on indigenous knowledge of ecosystem services. The ecosystem service framework and its associated concepts are fairly young, having been introduced in the ecological discipline in the 1980s. The ecosystem service framework posits that the wellbeing of humans and their communities is dependent on services supplied by ecosystems. It emphasises that for the ecosystems to be able to supply the services, they need to be in a well-functioning state. This idea of well-functioning is predicated on the argument that the ecosystem service framework enjoins resource users to exercise responsible stewardship to prevent degradation and overharvesting. Moreover, the concept of dependence suggests that ecosystem services are of value to humans. The dominant means of measuring the value of ecosystem services has been the economic valuation method in which the contribution that each service makes to human wellbeing is quantified into monetary units. The framework disaggregates the services into four groups, namely provisioning, cultural, supporting and regulatory and seeks to all the pillars of human wellbeing including health, subsistence and spirituality into each of these groups. In doing all this, the framework significantly reconfigures the way we look at and present human-nature relations. This change has the potential to influence significant shifts in how ecological research and intervention programmes are conducted in the foreseeable future. However, the reality that the ecosystem service framework was formulated within, and is informed by the scientific epistemology begs the question: what do traditional rural communities who depend mainly on indigenous knowledge systems (IKS) for shaping and interoperating their relations with nature know of the ecosystem service concept? Rural communities are the ones who interact directly with nature on a day-to-day basis. This makes them a very critical component in the ecosystem service framework. Although South Africa has had studies in the ecosystem service theme, little has been done to attempt to investigate and document indigenous knowledge of ecosystem services that rural communities possess. By focusing only on scientific knowledge of ecosystem services, the South African literature does not do justice to the plural epistemologies of the ecosystem service users in the country. More importantly, the continued dearth of public information on indigenous knowledge of ecosystem services can potentially obstruct implementation of locally sensitive intervention programmes because nothing is known about how the local communities conceptualise the ecosystem service framework. All this presents a crucial gap in the South African research; one that unless effort is made to contribute towards filling it, our knowledge of how communities experience the ecosystem service framework in South Africa will remain skewed. This study set out to investigate and document indigenous knowledge of ecosystem services in order to contribute towards filling this gap. Indigenous knowledge system is an umbrella epistemic system that includes lay ecological knowledge (LEK), traditional ecological knowledge (TEK) and many other related organized systems of knowing. Although the thesis has a chapter on LEK, its primary focus was TEK because the thesis was interested in unravelling how aspects of tradition including taboos, customs, traditional rules and belief in ancestral forces influence local communities’ knowledge of some key aspects of the ecosystem service framework including knowledge of various ecosystem services, valuation of ecosystem services, management of ecosystem services and perceptions of the management practices. The decision to focus on TEK was based on the reasoning that rural communities of the Eastern Cape boast a strong reputation of being traditional, recognizing ancestral spirits, legends and taboos as critical tools of knowledge generation and transmission. Using both mixed methods in some chapters and the qualitative approach alone in others, the study collected data in five villages of Mgwalana, Mahlungulu, Colana, Gogela and Nozitshena located in the north eastern part of Eastern Cape Province of South Africa, a region formerly called Transkei. The data were collected not on ecosystem services; but on the local people’s knowledge of ecosystem services. Although literature was consulted, the study regarded respondents as the primary source of data, hence the findings and conclusions presented in this thesis are about what local people know about ecosystem services. The study uses critical realist theoretical lenses to interpret respondents’ reports. The lenses included the principle of the separation between ontology and epistemology, the iceberg metaphor of ontology, epistemological pluralism and the hermeneutic dimension. These lenses were used to make sense of both the knowledge system of local people and the things about which their knowledge was. As part of discussing the local people’s knowledge, the study sometimes refers to science. This is not because I expected them to demonstrate knowledge similar to science. Instead, it was a critical realist dialectical way of explaining what something is by demonstrating what it is not. The study made a couple of key findings that can potentially enhance the growth of the South African ecosystem service discipline. First, respondents demonstrated knowledge of ecosystem services by mentioning a range of them such as drinking water, medicinal plants, cultural plants and fuelwood and how they affect the wellbeing of humans. However, what they did not have good knowledge of is that nature services can be classified into the four groups of supporting, regulatory, cultural and provisioning. Among the four ecosystem services groups, respondents could identify two only; provisional and cultural. Second, local communities depend heavily on ecosystem services for their well-being. The services include fuelwood, construction timber, medicinal plants, wild fruits, wild fish, cultural services and thatch grass. Although they appreciate that ecosystem services have value to their wellbeing, local people found it difficult to represent the value in monetary units. The conditions that make it difficult for local people to perceive ecosystem services as commodities include the absence of well-defined property system, lack of a quantitative consumer tradition and absence of an economic conception of nature. Third, local people understand the need to keep ecosystems in a well-functioning state hence they implement several traditional practices to manage ecosystem services. These practices include taboos, designating certain resources as sacred, legends, customary law, as well as some secular practices including gelesha and stone terracing. However, it is not easy to understand how traditional management practices work because they are not empirically observable. Fourth, local people possess knowledge of the reality that if not well managed, ecosystems can undergo degradation and hence fail to supply the services needed for human wellbeing. However, they explain the causes of degradation in terms of changes observable at the empirical level and the invisible causal power of supernatural forces. The inclusion of natural forces in degradation explanations marks a departure from the scientific explanations that revolve around biophysical processes. Fifth, the use of traditional management practices such as taboos to management ecosystems is under threat at the local communities. The threat can be attributed to three groups of causes, namely changes in worldviews due to adoption of formal education and Christianity, institutional disharmony playing out between the state and local traditional leadership, and lifestyle changes. These challenges constrain the opportunity for local people to apply traditional management practices to prevent the degradation of ecosystems. The net implication of this is that it renders it difficult for researchers and policy makers to assess the effectiveness of traditional management practices because they are not being implemented in full. In light of all these findings, the thesis concludes that TEK is underlabouring for the ecosystem service framework in the sense that it is used by local communities to generate knowledge of ecological concepts and phenomena. This means that TEK does not exist for the sake of its own self. Drawing from this finding, the study proposes a framework of analysing TEK as an underlabourer for social-ecological triggers or issues. Nonetheless, there are few factors that can be sources of limitation to the study. These include the reality that it was difficult to access pure traditional knowledge because over the years the local communities have received many state-sponsored ecological intervention programmes and a possible personal bias given the reality that I grew up in a traditional household and my father was a key holder or TEK. , Thesis (PhD) -- Faculty of Science, Environmental Science, 2021 , Thesis chapter to be published in 'Green and Low-Carbon Economy'. Journal available: https://ojs.bonviewpress.com/index.php/GLCE/index
- Full Text:
- Date Issued: 2021-04
Investigating the factors that influence use of ICTs for citizen engagement in Malawi
- Authors: Sibande, Rachel Chavula
- Date: 2021-04
- Subjects: Information technology -- Malawi , Political participation -- Malawi , Mobile apps -- Malawi , UTAUT , Mzinda
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177019 , vital:42782 , 10.21504/10962/177019
- Description: Literature has suggested that Malawians are keen to participate. Malawian’s willingness to participate is evident as the country has recorded high voter turnouts during the elections in recent decades. However, literature also suggests that there is minimal citizen engagement in between elections. Elsewhere, Information and Communication Technologies (ICTs) have been used to enhance citizen engagement, but ICT led citizen engagement is still an emerging field and yet to be explored as an area of research particularly in Malawi. We thus sought to explore if the use of ICTs could improve citizen engagement with councils, councilors, and utility companies that provide water and electricity in Malawi. We developed and deployed an ICT platform called Mzinda which means My location in Malawi’s populous Chichewa language. The platform provided various channels for citizens and duty bearers to engage via SMS, USSD, web and a mobile application. We sought to understand the factors that influence citizen’s behavior intention to use an ICT platform to engage. We applied the modified UTAUT model by including Attitude and Self Efficacy social constructs that have among others been cited as limitations of the UTAUT model. We conducted factor loadings of six social constructs of the modified UTAUT model to validate content and reexamine the model in the context of citizen engagement using ICTs in Malawi. We found that, Attitude and Self Efficacy were not significant determinants of the Behaviour Intention for citizens to use the ICT platform. However, 75% of the Behaviour Intention was influenced by Perfomance Expectancy and Effort Expectancy as moderated by age and gender. Empirical evidence showed that responsiveness and actionability of councils and councillors had improved. We also learned that citizens believed that service delivery had improved and that they had more influence over councils, councillors, and the utility companies because of using the ICT platform. We conclude by noting that improvements in service delivery; enhanced responsiveness and actionability of councils, councillors and the utility companies were not necessarily as a result of the ICT platform alone; but a combination of ICTs and non-technology mechanisms of engaging the stakeholders through community campaigns, radio programs, print media engagement, community meetings and debates among others. It is evident that ICTs are not the panacea of all citizen engagement problems. This research can be useful to researchers and practitioners in the technology and citizen engagement domains. , Thesis (MSc) -- Faculty of Science, Department of Computer Science, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Sibande, Rachel Chavula
- Date: 2021-04
- Subjects: Information technology -- Malawi , Political participation -- Malawi , Mobile apps -- Malawi , UTAUT , Mzinda
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177019 , vital:42782 , 10.21504/10962/177019
- Description: Literature has suggested that Malawians are keen to participate. Malawian’s willingness to participate is evident as the country has recorded high voter turnouts during the elections in recent decades. However, literature also suggests that there is minimal citizen engagement in between elections. Elsewhere, Information and Communication Technologies (ICTs) have been used to enhance citizen engagement, but ICT led citizen engagement is still an emerging field and yet to be explored as an area of research particularly in Malawi. We thus sought to explore if the use of ICTs could improve citizen engagement with councils, councilors, and utility companies that provide water and electricity in Malawi. We developed and deployed an ICT platform called Mzinda which means My location in Malawi’s populous Chichewa language. The platform provided various channels for citizens and duty bearers to engage via SMS, USSD, web and a mobile application. We sought to understand the factors that influence citizen’s behavior intention to use an ICT platform to engage. We applied the modified UTAUT model by including Attitude and Self Efficacy social constructs that have among others been cited as limitations of the UTAUT model. We conducted factor loadings of six social constructs of the modified UTAUT model to validate content and reexamine the model in the context of citizen engagement using ICTs in Malawi. We found that, Attitude and Self Efficacy were not significant determinants of the Behaviour Intention for citizens to use the ICT platform. However, 75% of the Behaviour Intention was influenced by Perfomance Expectancy and Effort Expectancy as moderated by age and gender. Empirical evidence showed that responsiveness and actionability of councils and councillors had improved. We also learned that citizens believed that service delivery had improved and that they had more influence over councils, councillors, and the utility companies because of using the ICT platform. We conclude by noting that improvements in service delivery; enhanced responsiveness and actionability of councils, councillors and the utility companies were not necessarily as a result of the ICT platform alone; but a combination of ICTs and non-technology mechanisms of engaging the stakeholders through community campaigns, radio programs, print media engagement, community meetings and debates among others. It is evident that ICTs are not the panacea of all citizen engagement problems. This research can be useful to researchers and practitioners in the technology and citizen engagement domains. , Thesis (MSc) -- Faculty of Science, Department of Computer Science, 2021
- Full Text:
- Date Issued: 2021-04
Mapping the pyrroloiminoquinone diversity produced by latrunculid sponges using tandem mass spectrometry-driven molecular networking
- Authors: Kalinski, Jarmo-Charles
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178468 , vital:42942
- Description: Access restricted until April 2023. , Thesis (PhD) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Kalinski, Jarmo-Charles
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178468 , vital:42942
- Description: Access restricted until April 2023. , Thesis (PhD) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-04
The development of an ionospheric storm-time index for the South African region
- Authors: Tshisaphungo, Mpho
- Date: 2021-04
- Subjects: Ionospheric storms -- South Africa , Global Positioning System , Neural networks (Computer science) , Regression analysis , Ionosondes , Auroral electrojet , Geomagnetic indexes , Magnetic storms -- South Africa
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178409 , vital:42937 , 10.21504/10962/178409
- Description: This thesis presents the development of a regional ionospheric storm-time model which forms the foundation of an index to provide a quick view of the ionospheric storm effects over South African mid-latitude region. The model is based on the foF2 measurements from four South African ionosonde stations. The data coverage for the model development over Grahamstown (33.3◦S, 26.5◦E), Hermanus (34.42◦S, 19.22◦E), Louisvale (28.50◦S, 21.20◦E), and Madimbo (22.39◦S, 30.88◦E) is 1996-2016, 2009-2016, 2000-2016, and 2000-2016 respectively. Data from the Global Positioning System (GPS) and radio occultation (RO) technique were used during validation. As the measure of either positive or negative storm effect, the variation of the critical frequency of the F2 layer (foF2) from the monthly median values (denoted as _foF2) is modeled. The modeling of _foF2 is based on only storm time data with the criteria of Dst 6 -50 nT and Kp > 4. The modeling methods used in the study were artificial neural network (ANN), linear regression (LR) and polynomial functions. The approach taken was to first test the modeling techniques on a single station before expanding the study to cover the regional aspect. The single station modeling was developed based on ionosonde data over Grahamstown. The inputs for the model which related to seasonal variation, diurnal variation, geomagnetic activity and solar activity were considered. For the geomagnetic activity, three indices namely; the symmetric disturbance in the horizontal component of the Earth’s magnetic field (SYM − H), the Auroral Electrojet (AE) index and local geomagnetic index A, were included as inputs. The performance of a single station model revealed that, of the three geomagnetic indices, SYM − H index has the largest contribution of 41% and 54% based on ANN and LR techniques respectively. The average correlation coefficients (R) for both ANN and LR models was 0.8, when validated during the selected storms falling within the period of model development. When validated using storms that fall outside the period of model development, the model gave R values of 0.6 and 0.5 for ANN and LR respectively. In addition, the GPS total electron content (TEC) derived measurements were used to estimate foF2 data. This is because there are more GPS receivers than ionosonde locations and the utilisation of this data increases the spatial coverage of the regional model. The estimation of foF2 from GPS TEC was done at GPS-ionosonde co-locations using polynomial functions. The average R values of 0.69 and 0.65 were obtained between actual and derived _foF2 over the co-locations and other GPS stations respectively. Validation of GPS TEC derived foF2 with RO data over regions out of ionospheric pierce points coverage with respect to ionosonde locations gave R greater than 0.9 for the selected storm period of 4-8 August 2011. The regional storm-time model was then developed based on the ANN technique using the four South African ionosonde stations. The maximum and minimum R values of 0.6 and 0.5 were obtained over ionosonde and GPS locations respectively. This model forms the basis towards the regional ionospheric storm-time index. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Tshisaphungo, Mpho
- Date: 2021-04
- Subjects: Ionospheric storms -- South Africa , Global Positioning System , Neural networks (Computer science) , Regression analysis , Ionosondes , Auroral electrojet , Geomagnetic indexes , Magnetic storms -- South Africa
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178409 , vital:42937 , 10.21504/10962/178409
- Description: This thesis presents the development of a regional ionospheric storm-time model which forms the foundation of an index to provide a quick view of the ionospheric storm effects over South African mid-latitude region. The model is based on the foF2 measurements from four South African ionosonde stations. The data coverage for the model development over Grahamstown (33.3◦S, 26.5◦E), Hermanus (34.42◦S, 19.22◦E), Louisvale (28.50◦S, 21.20◦E), and Madimbo (22.39◦S, 30.88◦E) is 1996-2016, 2009-2016, 2000-2016, and 2000-2016 respectively. Data from the Global Positioning System (GPS) and radio occultation (RO) technique were used during validation. As the measure of either positive or negative storm effect, the variation of the critical frequency of the F2 layer (foF2) from the monthly median values (denoted as _foF2) is modeled. The modeling of _foF2 is based on only storm time data with the criteria of Dst 6 -50 nT and Kp > 4. The modeling methods used in the study were artificial neural network (ANN), linear regression (LR) and polynomial functions. The approach taken was to first test the modeling techniques on a single station before expanding the study to cover the regional aspect. The single station modeling was developed based on ionosonde data over Grahamstown. The inputs for the model which related to seasonal variation, diurnal variation, geomagnetic activity and solar activity were considered. For the geomagnetic activity, three indices namely; the symmetric disturbance in the horizontal component of the Earth’s magnetic field (SYM − H), the Auroral Electrojet (AE) index and local geomagnetic index A, were included as inputs. The performance of a single station model revealed that, of the three geomagnetic indices, SYM − H index has the largest contribution of 41% and 54% based on ANN and LR techniques respectively. The average correlation coefficients (R) for both ANN and LR models was 0.8, when validated during the selected storms falling within the period of model development. When validated using storms that fall outside the period of model development, the model gave R values of 0.6 and 0.5 for ANN and LR respectively. In addition, the GPS total electron content (TEC) derived measurements were used to estimate foF2 data. This is because there are more GPS receivers than ionosonde locations and the utilisation of this data increases the spatial coverage of the regional model. The estimation of foF2 from GPS TEC was done at GPS-ionosonde co-locations using polynomial functions. The average R values of 0.69 and 0.65 were obtained between actual and derived _foF2 over the co-locations and other GPS stations respectively. Validation of GPS TEC derived foF2 with RO data over regions out of ionospheric pierce points coverage with respect to ionosonde locations gave R greater than 0.9 for the selected storm period of 4-8 August 2011. The regional storm-time model was then developed based on the ANN technique using the four South African ionosonde stations. The maximum and minimum R values of 0.6 and 0.5 were obtained over ionosonde and GPS locations respectively. This model forms the basis towards the regional ionospheric storm-time index. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2021
- Full Text:
- Date Issued: 2021-04
The effect of various substrate pretreatment methods on the enzymatic degradability of a Eucalyptus sp. – a potential feedstock for producing fermentable sugars
- Authors: Thoresen, Mariska
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178580 , vital:42952
- Description: Access restricted until April 2022. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Thoresen, Mariska
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178580 , vital:42952
- Description: Access restricted until April 2022. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
The effects of aspect, directional heating and depth on bedrock temperatures and the potential relationship with thermal fatigue weathering
- Authors: Breytenbach, Izak Johannes
- Date: 2021-04
- Subjects: Weathering -- South Africa -- Karoo , Shields (Geology) -- South Africa -- Karoo , Shields (Geology) -- Thermal properties , Tillite -- South Africa -- Karoo
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177688 , vital:42847 , 10.21504/10962/177688
- Description: Geomorphological weathering processes and their relationship with temperature fluctuations are frequently researched. These research efforts are mostly restricted to surface conditions where soils, loose-lying rocks or rock outcrops are assessed. However, there is a shortcoming in the understanding of the thermal properties in a rock mass, particularly in the upper metres below the surface, as this has not been investigated or researched in any great detail. The research reported here is unique in this regard as it exploited the use of rotary core boreholes in tillite bedrock in the Karoo (Western Cape, South Africa) which were drilled as part of an invasive materials investigation for a proposed new hard rock quarry to supply road stone. Temperature data were captured on a bedrock ridge hosting tillite outcrop with a strong east to west orientation. The site work was done in two separate phases. The initial phase of research saw data being captured for one year on two aspects (i.e. north and south) at a depth of 0.3 m. This was followed by the second (more detailed) phase, where three aspects were assessed (i.e. north, south and a flat crest), but at depths of 0.3 m, 2.0 m and 6.0 m, totalling nine data acquisition points. The second investigation phase gathered data for seven months. Supplementary weather data were also captured for the site. Subsequent data analyses revealed that there is much to learn about the thermal behaviour of bedrock in the upper metres below the surface, and that the temperature properties or thermal regimes are not as simple as often assumed. Temperature differences related to aspect are not only surficial, but are transmitted to underlying bedrock, and notable temperature differences were measurable to a depth of at least 6.0 m. Seasonal temperature fluctuations also have a pronounced effect on the rock mass temperatures and it was proven that deeper parts of the bedrock accumulate and dissipate heat at different (i.e. retarded) rates compared with shallower parts of the rock mass, creating suitable thermal conditions to induce thermal fatigue. Thermal properties were also proven to be non-linear. During analyses, the concept of temperature inversions was proven, whereby one part of the bedrock becomes hotter or cooler relative to another/adjacent part of the bedrock, compared with its earlier temperature state. It was argued that these temperature inversions may exacerbate thermal fatigue. This research proved that aspect (i.e. directional heating) and depth need to be considered when analysing thermal regimes in a rock mass, as these have a distinct influence. The effects which manifest themselves create suitable conditions for thermal fatigue, not only near the surface but also at depth in the bedrock. Lastly, the effects of meteorological conditions on shallow bedrock temperatures were assessed. Preliminary findings suggest that boundary conditions and meteorological processes may indeed affect shallow bedrock temperatures, but only under certain circumstances and not to the same extent as reported in the literature for conditions researched at the surface. Wind temperature relative to the rock temperature, as well as a combination of wind and rain were found to be the most significant factors. , Thesis (PhD) -- Faculty of Science, Geography, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Breytenbach, Izak Johannes
- Date: 2021-04
- Subjects: Weathering -- South Africa -- Karoo , Shields (Geology) -- South Africa -- Karoo , Shields (Geology) -- Thermal properties , Tillite -- South Africa -- Karoo
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177688 , vital:42847 , 10.21504/10962/177688
- Description: Geomorphological weathering processes and their relationship with temperature fluctuations are frequently researched. These research efforts are mostly restricted to surface conditions where soils, loose-lying rocks or rock outcrops are assessed. However, there is a shortcoming in the understanding of the thermal properties in a rock mass, particularly in the upper metres below the surface, as this has not been investigated or researched in any great detail. The research reported here is unique in this regard as it exploited the use of rotary core boreholes in tillite bedrock in the Karoo (Western Cape, South Africa) which were drilled as part of an invasive materials investigation for a proposed new hard rock quarry to supply road stone. Temperature data were captured on a bedrock ridge hosting tillite outcrop with a strong east to west orientation. The site work was done in two separate phases. The initial phase of research saw data being captured for one year on two aspects (i.e. north and south) at a depth of 0.3 m. This was followed by the second (more detailed) phase, where three aspects were assessed (i.e. north, south and a flat crest), but at depths of 0.3 m, 2.0 m and 6.0 m, totalling nine data acquisition points. The second investigation phase gathered data for seven months. Supplementary weather data were also captured for the site. Subsequent data analyses revealed that there is much to learn about the thermal behaviour of bedrock in the upper metres below the surface, and that the temperature properties or thermal regimes are not as simple as often assumed. Temperature differences related to aspect are not only surficial, but are transmitted to underlying bedrock, and notable temperature differences were measurable to a depth of at least 6.0 m. Seasonal temperature fluctuations also have a pronounced effect on the rock mass temperatures and it was proven that deeper parts of the bedrock accumulate and dissipate heat at different (i.e. retarded) rates compared with shallower parts of the rock mass, creating suitable thermal conditions to induce thermal fatigue. Thermal properties were also proven to be non-linear. During analyses, the concept of temperature inversions was proven, whereby one part of the bedrock becomes hotter or cooler relative to another/adjacent part of the bedrock, compared with its earlier temperature state. It was argued that these temperature inversions may exacerbate thermal fatigue. This research proved that aspect (i.e. directional heating) and depth need to be considered when analysing thermal regimes in a rock mass, as these have a distinct influence. The effects which manifest themselves create suitable conditions for thermal fatigue, not only near the surface but also at depth in the bedrock. Lastly, the effects of meteorological conditions on shallow bedrock temperatures were assessed. Preliminary findings suggest that boundary conditions and meteorological processes may indeed affect shallow bedrock temperatures, but only under certain circumstances and not to the same extent as reported in the literature for conditions researched at the surface. Wind temperature relative to the rock temperature, as well as a combination of wind and rain were found to be the most significant factors. , Thesis (PhD) -- Faculty of Science, Geography, 2021
- Full Text:
- Date Issued: 2021-04
The further development, application and evaluation of a sediment yield model (WQSED) for catchment management in African catchments
- Authors: Gwapedza, David
- Date: 2021-04
- Subjects: Sedimentation and deposition -- South Africa , Sedimentation and deposition -- Zimbabwe , Watersheds -- South Africa , Watersheds -- Zimbabwe , Watershed management -- Africa , Water quality -- South Africa , Water quality -- Zimbabwe , Modified Universal Soil Loss Equation (MUSLE) , Water Quality and Sediment Model (WQSED) , Soil and Water Assessment Tool (SWAT)
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178376 , vital:42934 , 10.21504/10962/178376
- Description: Erosion and sediment transport are natural catchment processes that play an essential role in ecosystem functioning by providing habitat for aquatic organisms and contributing to the health of wetlands. However, excessive erosion and sedimentation, mostly driven by anthropogenic activity, lead to ecosystem degradation, loss of agricultural land, water quality problems, reduced reservoir storage capacity and damage to physical infrastructure. It is reported that up to 25% of dams in South Africa have lost approximately 30% of their initial storage capacity to sedimentation. Therefore, excessive sedimentation transcends from an ecological problem to a health, livelihood and water security issue. Erosion and sedimentation occur at variable temporal and spatial scales; therefore, monitoring of these processes can be difficult and expensive. Regardless of all these prohibiting factors, information on erosion and sediment remains an urgent requirement for the sustainable management of catchments. Models have evolved as tools to replicate and simulate complex natural processes to understand and manage these systems. Several models have been developed globally to simulate erosion and sediment transport. However, these models are not always applicable in Africa because 1) the conditions under which they were developed are not as relevant for African catchments 2) they have high data requirements and cannot be applied with ease in our data-scarce African catchments 3) they are sometimes complicated, and there are little training available or potential users simply have no time to dedicate towards learning these models. To respond to the problems of erosion, sedimentation, water quality and unavailability of applicable models, the current research further develops, applies and evaluates an erosion and sediment transport model, the Water Quality and Sediment Model (WQSED), for integration within the existing water resources framework in South Africa and application for practical catchment management. The WQSED was developed to simulate daily suspended sediment loads that are vital for water quality and quantity assessments. The WQSED was developed based on the Modified Universal Soil Loss Equation (MUSLE), and the Pitman model is a primary hydrological model providing forcing data, although flow data from independent sources may be used to drive the WQSED model. The MUSLE was developed in the United States of America, and this research attempts to improve the applicability of the MUSLE by identifying key issues that may impede its performance. Assessments conducted within the current research can be divided into scale assessment and application and evaluation assessment. The scale assessment involved evaluating spatial and temporal scale issues associated with the MUSLE. Spatial scale assessments were conducted using analytical and mathematical assessments on a hypothetical catchment. Temporal scale issues were assessed in terms of the vegetation cover (C) factor within the Tsitsa River catchment in South Africa. Model application and evaluation involved applying and calibrating the model to simulate daily time-series sediment yield. The model was applied to calibrated and validated (split-sample validation) in two catchments in South Africa, two catchments in Zimbabwe and three catchments were selected from the USA and associated territories for further testing as continuous daily time-series observed sediment data could not be readily accessed for catchments in the Southern African region. The catchments where the model was calibrated and validated range in size from 50 km2 to 20 000 km2. Additionally, the model was applied to thirteen ‘ungauged’ catchments selected from across South Africa, where only long-term reservoir sedimentation rates were available to compare with long term model simulations converted to sediment yield rates. The additional thirteen catchments were selected from areas of different climatic, vegetation and soils conditions characterising South Africa and range in size from 30 km2 to 2 500 km2. The current research results are split into a) MUSLE scale dependency and b) WQSED testing and evaluation. Scale dependency testing showed that the MUSLE could be spatially scale-dependent, particularly when a lumped approach is used, resulting in simulations of up to 30% more sediment. Spatial scale dependence in the MUSLE was found to be related to the runoff and topographic factors used and how they are calculated. The current study resorted to adopting a reference grid in applying the MUSLE, followed by scaling up the outputs to the total catchment area. Using a reference grid resulted in a general avoidance of the problem of spatial scale. The adoption of a seasonal vegetation cover factor was shown to significantly account for temporal changes of vegetation cover within a year and reduce over-estimations in sediment output. The temporal scale evaluation demonstrated the uncertainties associated with using a fixed vegetation cover factor in a catchment with variable rainfall and runoff pattern. The WQSED model evaluation showed that the model could be calibrated and validated to provide consistent results. Satisfactory model evaluation statistics were obtained for most catchments to which the model was applied, based on general model evaluation guidelines (Nash Sutcliffe Efficiency and R2 > 0.5). The model also performed generally well compared to established models that had been previously applied in some of the study catchments. The highest sediment yields recorded per country were 153 t km-2 year-1 (Tsitsa River; South Africa), 90 t km-2 year-1 (Odzi River; Zimbabwe) and 340 t km-2 year-1 (Rio Tanama; Puerto Rico). The results also displayed consistent underestimations of peak sediment yield events, partly attributed to sediment emanating from gullies that are not explicitly accounted for in the WQSED model structure. Furthermore, the calibration process revealed that the WQSED storage model is generally challenging to calibrate. An alternative simpler version of the storage model was easier to calibrate, but the model may still be challenging to apply to catchments where calibration data are not available. The additional evaluation of the WQSED simulated sediment yield rates against observed reservoir sediment rates showed a broad range of differences between the simulated and observed sediment yield rates. Differences between WQSED simulated sediment and observed reservoir sediment ranges from a low of 30% to a high of > 40 times. The large differences were partly attributed to WQSED being limited to simulating suspended sediment from sheet and rill processes, whereas reservoir sediment is generated from more sources that include bedload, channel and gully processes. Nevertheless, the model simulations replicated some of the regional sediment yield patterns and are assumed to represent sheet and rill contributions to reservoir sediment in selected catchments. The outcome of this study is an improved WQSED model that has successfully undergone preliminary testing and evaluation. Therefore, the model is sufficiently complete to be used by independent researchers and water resources managers to simulate erosion and sediment transport. However, the model is best applicable to areas where some observed data or regional information are available to calibrate the storage components and constrain model outputs. The report on potential MUSLE scale dependencies is relevant globally to all studies applying the MUSLE model and, therefore, can improve MUSLE application in future studies. The WQSED model offers a relatively simple, effective and applicable tool that is set to provide information to enhance catchment, land and water resources management in catchments of Africa. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Gwapedza, David
- Date: 2021-04
- Subjects: Sedimentation and deposition -- South Africa , Sedimentation and deposition -- Zimbabwe , Watersheds -- South Africa , Watersheds -- Zimbabwe , Watershed management -- Africa , Water quality -- South Africa , Water quality -- Zimbabwe , Modified Universal Soil Loss Equation (MUSLE) , Water Quality and Sediment Model (WQSED) , Soil and Water Assessment Tool (SWAT)
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178376 , vital:42934 , 10.21504/10962/178376
- Description: Erosion and sediment transport are natural catchment processes that play an essential role in ecosystem functioning by providing habitat for aquatic organisms and contributing to the health of wetlands. However, excessive erosion and sedimentation, mostly driven by anthropogenic activity, lead to ecosystem degradation, loss of agricultural land, water quality problems, reduced reservoir storage capacity and damage to physical infrastructure. It is reported that up to 25% of dams in South Africa have lost approximately 30% of their initial storage capacity to sedimentation. Therefore, excessive sedimentation transcends from an ecological problem to a health, livelihood and water security issue. Erosion and sedimentation occur at variable temporal and spatial scales; therefore, monitoring of these processes can be difficult and expensive. Regardless of all these prohibiting factors, information on erosion and sediment remains an urgent requirement for the sustainable management of catchments. Models have evolved as tools to replicate and simulate complex natural processes to understand and manage these systems. Several models have been developed globally to simulate erosion and sediment transport. However, these models are not always applicable in Africa because 1) the conditions under which they were developed are not as relevant for African catchments 2) they have high data requirements and cannot be applied with ease in our data-scarce African catchments 3) they are sometimes complicated, and there are little training available or potential users simply have no time to dedicate towards learning these models. To respond to the problems of erosion, sedimentation, water quality and unavailability of applicable models, the current research further develops, applies and evaluates an erosion and sediment transport model, the Water Quality and Sediment Model (WQSED), for integration within the existing water resources framework in South Africa and application for practical catchment management. The WQSED was developed to simulate daily suspended sediment loads that are vital for water quality and quantity assessments. The WQSED was developed based on the Modified Universal Soil Loss Equation (MUSLE), and the Pitman model is a primary hydrological model providing forcing data, although flow data from independent sources may be used to drive the WQSED model. The MUSLE was developed in the United States of America, and this research attempts to improve the applicability of the MUSLE by identifying key issues that may impede its performance. Assessments conducted within the current research can be divided into scale assessment and application and evaluation assessment. The scale assessment involved evaluating spatial and temporal scale issues associated with the MUSLE. Spatial scale assessments were conducted using analytical and mathematical assessments on a hypothetical catchment. Temporal scale issues were assessed in terms of the vegetation cover (C) factor within the Tsitsa River catchment in South Africa. Model application and evaluation involved applying and calibrating the model to simulate daily time-series sediment yield. The model was applied to calibrated and validated (split-sample validation) in two catchments in South Africa, two catchments in Zimbabwe and three catchments were selected from the USA and associated territories for further testing as continuous daily time-series observed sediment data could not be readily accessed for catchments in the Southern African region. The catchments where the model was calibrated and validated range in size from 50 km2 to 20 000 km2. Additionally, the model was applied to thirteen ‘ungauged’ catchments selected from across South Africa, where only long-term reservoir sedimentation rates were available to compare with long term model simulations converted to sediment yield rates. The additional thirteen catchments were selected from areas of different climatic, vegetation and soils conditions characterising South Africa and range in size from 30 km2 to 2 500 km2. The current research results are split into a) MUSLE scale dependency and b) WQSED testing and evaluation. Scale dependency testing showed that the MUSLE could be spatially scale-dependent, particularly when a lumped approach is used, resulting in simulations of up to 30% more sediment. Spatial scale dependence in the MUSLE was found to be related to the runoff and topographic factors used and how they are calculated. The current study resorted to adopting a reference grid in applying the MUSLE, followed by scaling up the outputs to the total catchment area. Using a reference grid resulted in a general avoidance of the problem of spatial scale. The adoption of a seasonal vegetation cover factor was shown to significantly account for temporal changes of vegetation cover within a year and reduce over-estimations in sediment output. The temporal scale evaluation demonstrated the uncertainties associated with using a fixed vegetation cover factor in a catchment with variable rainfall and runoff pattern. The WQSED model evaluation showed that the model could be calibrated and validated to provide consistent results. Satisfactory model evaluation statistics were obtained for most catchments to which the model was applied, based on general model evaluation guidelines (Nash Sutcliffe Efficiency and R2 > 0.5). The model also performed generally well compared to established models that had been previously applied in some of the study catchments. The highest sediment yields recorded per country were 153 t km-2 year-1 (Tsitsa River; South Africa), 90 t km-2 year-1 (Odzi River; Zimbabwe) and 340 t km-2 year-1 (Rio Tanama; Puerto Rico). The results also displayed consistent underestimations of peak sediment yield events, partly attributed to sediment emanating from gullies that are not explicitly accounted for in the WQSED model structure. Furthermore, the calibration process revealed that the WQSED storage model is generally challenging to calibrate. An alternative simpler version of the storage model was easier to calibrate, but the model may still be challenging to apply to catchments where calibration data are not available. The additional evaluation of the WQSED simulated sediment yield rates against observed reservoir sediment rates showed a broad range of differences between the simulated and observed sediment yield rates. Differences between WQSED simulated sediment and observed reservoir sediment ranges from a low of 30% to a high of > 40 times. The large differences were partly attributed to WQSED being limited to simulating suspended sediment from sheet and rill processes, whereas reservoir sediment is generated from more sources that include bedload, channel and gully processes. Nevertheless, the model simulations replicated some of the regional sediment yield patterns and are assumed to represent sheet and rill contributions to reservoir sediment in selected catchments. The outcome of this study is an improved WQSED model that has successfully undergone preliminary testing and evaluation. Therefore, the model is sufficiently complete to be used by independent researchers and water resources managers to simulate erosion and sediment transport. However, the model is best applicable to areas where some observed data or regional information are available to calibrate the storage components and constrain model outputs. The report on potential MUSLE scale dependencies is relevant globally to all studies applying the MUSLE model and, therefore, can improve MUSLE application in future studies. The WQSED model offers a relatively simple, effective and applicable tool that is set to provide information to enhance catchment, land and water resources management in catchments of Africa. , Thesis (PhD) -- Faculty of Science, Institute for Water Research, 2021
- Full Text:
- Date Issued: 2021-04
The impact of translanguaging and acculturation towards implementation of the Incremental Indigenous African Languages programme in former Model-C schools (Alfred Nzo West District, Eastern Cape)
- Authors: Lepheana, Jeremia
- Date: 2021-04
- Subjects: Translanguaging (Linguistics) , Acculturation -- South Africa -- Eastern Cape , Model C schools (South Africa) , Multilingual education -- South Africa -- Eastern Cape , Multicultural education -- South Africa -- Eastern Cape , Incremental Indigenous African Languages Programme
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177236 , vital:42802 , 10.21504/10962/177236
- Description: This thesis explores the possibilities of multilingual language instruction within multi-ethnic classrooms in former Model-C schools shaped by multiple discursive practices. The researcher reviews current research on multilingualism and teaching and proposes strategies for overcoming the English prescriptivism, and monolingual mind-set in education. The research reported in this dissertation is both a qualitative and quantitative study, which sought to investigate the patterns of translanguaging in classrooms in five primary schools in Alfred Nzo West district (Maluti sub-district). In quantitative research, questionnaires were used to gather data from teachers and learners. In the qualitative research methodology, document analysis method of collecting data was employed. Purposive sampling was the major sampling method to ensure that relevant data was collected. Language in Education Policy formed the major analytical framework for this study. The aim of the study was to investigate the impact of translanguaging as it is used by teachers and learners in the class in selected primary schools in Alfred Nzo West district. The research focuses on how primary school learners and their teachers engage with teaching and learning, and the strategies that teachers use to promote the use of two or three languages in classrooms to help learners to understand content and concepts in English, Sesotho and isiXhosa as there are multi-ethnic classrooms in the district. The dissertation concludes with some reflections on the findings, implications of the findings for future research and training, and recommendations to use the languages of school children as rich resources for teaching and learning. The Socio-cultural theory formed the theoretical framework that guided this study. According to Vygotsky’s theory of cognitive development, children learn through social interaction that includes collaborative and cooperative dialogue with someone who is more skilled in tasks they are trying to learn. The findings of this study show the misunderstandings of the LiEP, translanguaging and multilingual education. The study also shows the lack of confidence in the ability of African languages to provide quality education. , Thesis (PhD) -- Faculty of Humanities, School of Languages, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Lepheana, Jeremia
- Date: 2021-04
- Subjects: Translanguaging (Linguistics) , Acculturation -- South Africa -- Eastern Cape , Model C schools (South Africa) , Multilingual education -- South Africa -- Eastern Cape , Multicultural education -- South Africa -- Eastern Cape , Incremental Indigenous African Languages Programme
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177236 , vital:42802 , 10.21504/10962/177236
- Description: This thesis explores the possibilities of multilingual language instruction within multi-ethnic classrooms in former Model-C schools shaped by multiple discursive practices. The researcher reviews current research on multilingualism and teaching and proposes strategies for overcoming the English prescriptivism, and monolingual mind-set in education. The research reported in this dissertation is both a qualitative and quantitative study, which sought to investigate the patterns of translanguaging in classrooms in five primary schools in Alfred Nzo West district (Maluti sub-district). In quantitative research, questionnaires were used to gather data from teachers and learners. In the qualitative research methodology, document analysis method of collecting data was employed. Purposive sampling was the major sampling method to ensure that relevant data was collected. Language in Education Policy formed the major analytical framework for this study. The aim of the study was to investigate the impact of translanguaging as it is used by teachers and learners in the class in selected primary schools in Alfred Nzo West district. The research focuses on how primary school learners and their teachers engage with teaching and learning, and the strategies that teachers use to promote the use of two or three languages in classrooms to help learners to understand content and concepts in English, Sesotho and isiXhosa as there are multi-ethnic classrooms in the district. The dissertation concludes with some reflections on the findings, implications of the findings for future research and training, and recommendations to use the languages of school children as rich resources for teaching and learning. The Socio-cultural theory formed the theoretical framework that guided this study. According to Vygotsky’s theory of cognitive development, children learn through social interaction that includes collaborative and cooperative dialogue with someone who is more skilled in tasks they are trying to learn. The findings of this study show the misunderstandings of the LiEP, translanguaging and multilingual education. The study also shows the lack of confidence in the ability of African languages to provide quality education. , Thesis (PhD) -- Faculty of Humanities, School of Languages, 2021
- Full Text:
- Date Issued: 2021-04
The Influence of Clientelism on the Informal Sector in Zimbabwe : a Case Study of Glen View 8 Complex, Harare
- Authors: Tandire, Justin
- Date: 2021-04
- Subjects: Patron and client -- Zimbabwe -- Harare , Informal sector (Economics) -- Zimbabwe -- Harare , Informal sector (Economics) -- Political aspects -- Zimbabwe -- Harare , Patronage, Political -- Zimbabwe -- Harare , ZANU-PF (Organization : Zimbabwe) , Zimbabwe -- Social conditions , Glen View Complex 8 (Zimbabwe)
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177986 , vital:42896 , 10.21504/10962/177986
- Description: This study focuses on the influence of clientelism in the informal sector of Zimbabwe in Glen View 8 (Complex). The study used the case of Glen view 8 (complex) in Harare Province. The study focused on political dynamics in the informal sector; livelihood strategies employed by informal sector operators; manifestation of “Big Men”, social networks in the informal sector; and different strategies employed by operators to overcome the problems of political manipulation, clientelism and patronage. It employs a qualitative research methodology to enable a nuanced comprehension of the clientelistic relationships that take place in the informal sector of Zimbabwe. Through in-depth interviews, focus group discussions, narratives and in-depth interviews with key informants, the study explored the clientelistic nature of the informal sector. The major findings of the study are that the informal sector in Zimbabwe is influenced by political patronage. It was established that patronage influences the informal sector in Zimbabwe in general and at Glen View Complex 8 in particular. Some of the operators revealed that patronage negatively affects their business as they are sometimes forced to attend political party meetings either at the complex or at ZANU-PF star rallies in town. The operators experience a plethora of problems such as lack of security, poor sanitation, stiff competition, poor infrastructure, lack of insurance and fire outbreaks. It has been revealed that most of the problems experienced at the complex are a result of the politicisation of the informal sector particularly by the ZANU-PF party. Operators at the complex have described the politicisation of the informal sector as a major drawback to their efforts of realising maximum benefits from their work. Therefore, the thrust of this thesis is premised on the de-politicisation of the informal sector as the starting point in the transformation of the activities of the operators. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Tandire, Justin
- Date: 2021-04
- Subjects: Patron and client -- Zimbabwe -- Harare , Informal sector (Economics) -- Zimbabwe -- Harare , Informal sector (Economics) -- Political aspects -- Zimbabwe -- Harare , Patronage, Political -- Zimbabwe -- Harare , ZANU-PF (Organization : Zimbabwe) , Zimbabwe -- Social conditions , Glen View Complex 8 (Zimbabwe)
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177986 , vital:42896 , 10.21504/10962/177986
- Description: This study focuses on the influence of clientelism in the informal sector of Zimbabwe in Glen View 8 (Complex). The study used the case of Glen view 8 (complex) in Harare Province. The study focused on political dynamics in the informal sector; livelihood strategies employed by informal sector operators; manifestation of “Big Men”, social networks in the informal sector; and different strategies employed by operators to overcome the problems of political manipulation, clientelism and patronage. It employs a qualitative research methodology to enable a nuanced comprehension of the clientelistic relationships that take place in the informal sector of Zimbabwe. Through in-depth interviews, focus group discussions, narratives and in-depth interviews with key informants, the study explored the clientelistic nature of the informal sector. The major findings of the study are that the informal sector in Zimbabwe is influenced by political patronage. It was established that patronage influences the informal sector in Zimbabwe in general and at Glen View Complex 8 in particular. Some of the operators revealed that patronage negatively affects their business as they are sometimes forced to attend political party meetings either at the complex or at ZANU-PF star rallies in town. The operators experience a plethora of problems such as lack of security, poor sanitation, stiff competition, poor infrastructure, lack of insurance and fire outbreaks. It has been revealed that most of the problems experienced at the complex are a result of the politicisation of the informal sector particularly by the ZANU-PF party. Operators at the complex have described the politicisation of the informal sector as a major drawback to their efforts of realising maximum benefits from their work. Therefore, the thrust of this thesis is premised on the de-politicisation of the informal sector as the starting point in the transformation of the activities of the operators. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2021
- Full Text:
- Date Issued: 2021-04
The role of open government data in the repurposing of land administration in postapartheid South Africa : an exploration
- Authors: Manona, Siyabulela Sobantu
- Date: 2021-04
- Subjects: Transparency in government -- South Africa , Land reform -- South Africa , Qualitative research -- Methodology , Postcolonialism -- South Africa , Post-apartheid era -- South Africa , South Africa -- Economic conditions -- 1991- , South Africa -- Social conditions -- 1994- , South Africa -- Politics and government -- 1994- , Open Government Data (OGD)
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178397 , vital:42936 , 10.21504/10962/178397
- Description: Almost three decades after the official end of the apartheid, South Africa has been on a sturdy path that is characterised by deepening spatial economic inequalities. A plethora of policy instruments unleashed since 1994 had not only failed to stem the tide of poverty and inequality, but had deepened them. As part of this, South Africa’s most ambitious social engineering programme – land reform -- had disappointing outcomes. Premised on a view that these apartheid continuities were embedded in South Africa’s land administration system – which was incoherent and fragmented and requiring a systemic overhaul -- the study sought to explore the potential role of Open Government Data (OGD) in the repurposing of land administration system in the post-apartheid South Africa. To achieve this goal, the study was guided by the following objectives: to explore the ontology and the state of land governance and administration in the context of the post-apartheid South Africa; to undertake an evaluation or assessment of South Africa’s land data ecosystem; and to explore the potential role of OGD in the repurposing of land administration system in the postapartheid of South Africa. This study was steeped in qualitative research methods, underpinned by primary and secondary literature review. While the study was primarily pitched on a national scale – the combination of the systems and multiple scales approaches – yielded results which dislodges solutions that are required outside of the domain of a single state. This is one glaring example of land governance complexities that straddle beyond national scale – specifically in respect of new policy trajectories on trans-national boundaries and governance of water resources. Based on the holistic ontology of land, this study concludes that land administration and land governance overarching conceptual orientation -- concerned with land use decisions made by humans at various scales from a praxis and policy perspective –constitute two sides of the same coin, the former steeped towards practice and the latter steeped towards policy. Drawing from decolonial theories the study concludes that land does not only have multiple dimensions, but it also has multiple meanings, in a manner that calls for an ontological shift away from the western ontology, towards an inclusive and holistic conceptualisation. Historiography that is anchored in de-colonial thinking of South Africa’s land governance helps us understand how and why – colonial/apartheid norms acrimoniously found their way into the post-apartheid order -- the post-apartheid institutions of modernity rest on the same hierarchies of identities, classification and pathologisation. The study concludes that, while the colonial/apartheid administration may be gone, it’s underlying power matrices continue -- i.e. capitalism/European/patriachal/white – in a manner which explains the continuities of South Africa’s spatial inequalities and the associated economic inequalities. The organising principle for land relations (including opportunities) continues to be underpinned by gender, race and class, in ways that expose the mythical dimensions of the 'post-apartheid' underbelly. While identifying the need for homogenisation and rationalistion of colonial, apartheid and post-apartheid institutions (on a national scale) that is insufficient for the transformation of the colonial situation of what is in essence a part of the global system, the study advocates for the ‘repurposing of land governance and administration’ – underpinned by de-colonial thinking. Repurposing is seen as political imaginary that would entail uncoupling thought processes and praxis from the colonial matrices of power. The study goes on to conclude that there is a definite role for Open Government Data in repurposing of land administration in the post-apartheid South Africa – as a necessary, though in and of it’s own it is an insufficient condition to achieve that ideal -- but presents an opportunity to enhance transdisciplinarity approaches and efficiencies in internal government functioning and evidence-based decision making and policy formulation processes. , Thesis (PhD) -- Faculty of Science, Geography, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Manona, Siyabulela Sobantu
- Date: 2021-04
- Subjects: Transparency in government -- South Africa , Land reform -- South Africa , Qualitative research -- Methodology , Postcolonialism -- South Africa , Post-apartheid era -- South Africa , South Africa -- Economic conditions -- 1991- , South Africa -- Social conditions -- 1994- , South Africa -- Politics and government -- 1994- , Open Government Data (OGD)
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178397 , vital:42936 , 10.21504/10962/178397
- Description: Almost three decades after the official end of the apartheid, South Africa has been on a sturdy path that is characterised by deepening spatial economic inequalities. A plethora of policy instruments unleashed since 1994 had not only failed to stem the tide of poverty and inequality, but had deepened them. As part of this, South Africa’s most ambitious social engineering programme – land reform -- had disappointing outcomes. Premised on a view that these apartheid continuities were embedded in South Africa’s land administration system – which was incoherent and fragmented and requiring a systemic overhaul -- the study sought to explore the potential role of Open Government Data (OGD) in the repurposing of land administration system in the post-apartheid South Africa. To achieve this goal, the study was guided by the following objectives: to explore the ontology and the state of land governance and administration in the context of the post-apartheid South Africa; to undertake an evaluation or assessment of South Africa’s land data ecosystem; and to explore the potential role of OGD in the repurposing of land administration system in the postapartheid of South Africa. This study was steeped in qualitative research methods, underpinned by primary and secondary literature review. While the study was primarily pitched on a national scale – the combination of the systems and multiple scales approaches – yielded results which dislodges solutions that are required outside of the domain of a single state. This is one glaring example of land governance complexities that straddle beyond national scale – specifically in respect of new policy trajectories on trans-national boundaries and governance of water resources. Based on the holistic ontology of land, this study concludes that land administration and land governance overarching conceptual orientation -- concerned with land use decisions made by humans at various scales from a praxis and policy perspective –constitute two sides of the same coin, the former steeped towards practice and the latter steeped towards policy. Drawing from decolonial theories the study concludes that land does not only have multiple dimensions, but it also has multiple meanings, in a manner that calls for an ontological shift away from the western ontology, towards an inclusive and holistic conceptualisation. Historiography that is anchored in de-colonial thinking of South Africa’s land governance helps us understand how and why – colonial/apartheid norms acrimoniously found their way into the post-apartheid order -- the post-apartheid institutions of modernity rest on the same hierarchies of identities, classification and pathologisation. The study concludes that, while the colonial/apartheid administration may be gone, it’s underlying power matrices continue -- i.e. capitalism/European/patriachal/white – in a manner which explains the continuities of South Africa’s spatial inequalities and the associated economic inequalities. The organising principle for land relations (including opportunities) continues to be underpinned by gender, race and class, in ways that expose the mythical dimensions of the 'post-apartheid' underbelly. While identifying the need for homogenisation and rationalistion of colonial, apartheid and post-apartheid institutions (on a national scale) that is insufficient for the transformation of the colonial situation of what is in essence a part of the global system, the study advocates for the ‘repurposing of land governance and administration’ – underpinned by de-colonial thinking. Repurposing is seen as political imaginary that would entail uncoupling thought processes and praxis from the colonial matrices of power. The study goes on to conclude that there is a definite role for Open Government Data in repurposing of land administration in the post-apartheid South Africa – as a necessary, though in and of it’s own it is an insufficient condition to achieve that ideal -- but presents an opportunity to enhance transdisciplinarity approaches and efficiencies in internal government functioning and evidence-based decision making and policy formulation processes. , Thesis (PhD) -- Faculty of Science, Geography, 2021
- Full Text:
- Date Issued: 2021-04
An investigation into the mediation of the representation of gender roles in God of women : a critical discourse analysis of pedagogic practices in selected Namibian schools
- Nghikefelwa, Josephine Mwasheka
- Authors: Nghikefelwa, Josephine Mwasheka
- Date: 2021
- Subjects: Nyati, Sifiso. God of women , Stereotypes (Social psychology) in literature , Women in literature , English literature -- Study and teaching (Secondary) -- Namibia , Women's rights in literature , Women's rights -- Study and teaching (Secondary)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172389 , vital:42195 , 10.21504/10962/172389
- Description: This is a qualitative study designed to investigate the role of pedagogical practices in the mediation of stereotypical gender representations in the drama God of Women by Sifiso Nyathi (1998). This drama is one of the literature setworks for Grade 9 English Second Language learners in Namibian Secondary schools. Fairclough’s (2012) Critical Discourse Analysis was used as a research design, as well as the conceptual and analytical framework. The analysis of this drama by teachers during the teaching and learning process, pedagogic practices they employ, learners’ engagement in classroom activities, and the nature of comments that teachers write on students’ assignment, based on God of Women, formed part of the unit of analysis. The study explored teachers’ pedagogical practices during English Literature teaching to gain insight into whether and how teachers shape learners’ engagement with literature to promote critical thinking. Focus on the mediation process (‘teacher talks around the text’) concerned a close analysis of teachers’ engagement with the text during lessons. Semi-structured interviews, classroom observation and documentary evidence were used to generate data. The research site and study participants were purposively sampled.
- Full Text:
- Date Issued: 2021
- Authors: Nghikefelwa, Josephine Mwasheka
- Date: 2021
- Subjects: Nyati, Sifiso. God of women , Stereotypes (Social psychology) in literature , Women in literature , English literature -- Study and teaching (Secondary) -- Namibia , Women's rights in literature , Women's rights -- Study and teaching (Secondary)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172389 , vital:42195 , 10.21504/10962/172389
- Description: This is a qualitative study designed to investigate the role of pedagogical practices in the mediation of stereotypical gender representations in the drama God of Women by Sifiso Nyathi (1998). This drama is one of the literature setworks for Grade 9 English Second Language learners in Namibian Secondary schools. Fairclough’s (2012) Critical Discourse Analysis was used as a research design, as well as the conceptual and analytical framework. The analysis of this drama by teachers during the teaching and learning process, pedagogic practices they employ, learners’ engagement in classroom activities, and the nature of comments that teachers write on students’ assignment, based on God of Women, formed part of the unit of analysis. The study explored teachers’ pedagogical practices during English Literature teaching to gain insight into whether and how teachers shape learners’ engagement with literature to promote critical thinking. Focus on the mediation process (‘teacher talks around the text’) concerned a close analysis of teachers’ engagement with the text during lessons. Semi-structured interviews, classroom observation and documentary evidence were used to generate data. The research site and study participants were purposively sampled.
- Full Text:
- Date Issued: 2021
Chave Chemutengure Vhiri Rengoro : Husarungano Nerwendo Rwengano Dzevashona
- Authors: Mabasa, Ignatius T
- Date: 2021
- Subjects: Ethnology -- Zimbabwe , Zimbabwe -- Folklore , Shona (African people) -- Folklore , Ethnoscience , Decolonization in literature , Decolonization -- Africa , Autoethnography , Chemutengure , Subaltern
- Language: Shona
- Type: text , Thesis , Doctoral , PHD
- Identifier: http://hdl.handle.net/10962/174198 , vital:42454 , http://doi.org/10.21504/10962/174198
- Description: Tsvakurudzo ino inyaya yangu sasarungano nemunyori weChiShona, asiwo iri nyaya yevanhu veChiShona. Inyaya yekurerwa kwandakaitwa nengano, ndikaona ngano dzakandirera dzichipinzwa muzvikoro, dzichisangana nechirungu, dzichifambidzana nechirungu, nekuzopedzisira dzazvara mimwe misambo yengano. Basa rino maonero angu ndichishandisa nzira yetsvakurudzo inonzi husarungano, kureva muono wasarungano. Izvi zvinoreva kududzira nekutsanangura, kufungisisa nekupenengura humhizha hunowanikwa mutsika nemagariro angu, sasarungano ari kupfuurira mberi nekuita ngano munyika yazara chirungu. Naizvozvo, ini ndini musoro wenyaya yandiri kutaura, asiwo ndirini zvakare muiti wetsvakurudzo. Ndichishandisa zvandakasangana nazvo, nezvandinofunga nekuona sasarungano – ndinodzokera kuchimbo chinotaura nyaya yevaShona pakapinda vachena munyika yeZimbabwe. Ndinotsanangura zvinoreva Chemutengure, uye nekukosha kwacho mukufambisa ruzivo, mashoko nekutsanangura hupenyu hwedu sevanhu vatema vakanga vakadzvanyiriwa. Chemutengure mafungiro, imhenenguro, iyambiro nehungwaru. Ndinotsanangura ruzivo rwevanhu vangu nekushanduka kwarwo kwakakonzerwa nechirungu. Ndinoita izvi ndichipenengura ngano, mabhuku, nziyo, mafungiro nezvimwe zvimutengure zvakatakura ngano. Otoetinogirafu iyo yandichapa zita rekuti husarungano imhando yekuvhiya uchiita tsvakurudzo, uye inowanikwa pakati pehumhizha hwekunyora nyaya nekupenengura zvine chekuita nehumhizha hwetsika nemagariro evanhu. Husarungano hunovhurira musiwo vanhu vanowanzovharirwa kunze netsvakurudzo dzinoitwa mumayunivhesiti dzine mitauro isiri yavo uyewo dzimwe nguva isinganzwisisike zviri nyn’ore. Husarungano hunoshandisa rondedzero nengano kuti zvinhu zvinosanganisira hukama nezvakasanganikwa nazvo nevanhu zvinzwisisike, panguva imwechete pachiumbwa hukama pakati penguva dzakare nazvino, hukama pakati pevanoita tsvakurudzo nevavari kuita tsvakurudzo pamusoro pavo, hukama pakati pevanyori nevaverengi, vanasarungano nevateereri vengano (Adams nevamwe, 2015). Tsvakurudzo ino haisi kuzopedza zvese zvinofanira kutaurwa pamusoro pengano, tsika nemagariro evanhu vatema, kunyorwa kwemabhuku nezvimwe zvakawanda zvainobata nekutarisa, asi riripo kuratidza simba nehupfumi huri muruzivo rwevaShona rwuri kurariswa muberere memba, chirungu chichirariswa mumba. Shanduko yandiri kutarisa mubasa rino inoda kuti isu vanhu vatema tisarambe tichiverengera kuti tirongeke nekuronga mafambiro nemararamiro achaita ruzivo rwedu munyika iri kukoshesa ruzivo, maitiro nezvinhu zvinogadzirwa nevarungu. Kana tikasaronga kuti tipembedze nekuwanisa ruzivo rwedu mukana, tichaita mufakose – kurasikirwa nezvedu, nekusakwana kana kunyatsonzwisisa zvevamwe zvatiri kukoshesa. Ruzivo rwandakashandisa mubasa rino rwunosanganisira zvakaitika kwandiri kubva pandakatanga kuziva ngano dzandakaudzwa nambuya vangu, kubatsirwa kwangu nengano kuchikoro, kuve munyori wemabhuku, nekuenda kwangu mhiri kwemakungwa sasarungano. Zvakarewo ndiri kutarisa ngano dzakaunganidzwa nekunyorwa nemamishenari, ngano dzakanyorwa kare muNative Afffairs Department Annual (NADA), ngano dzakaitwa senziyo, ngano dzakaitwa neLiterature Bureau, nengano dzandave kuita dzemanon-governmental organisations (NGO), panhepfenyuro, paTwitter nezvimwe zvimutengure zvakasiyana-siyana. Hupfumi huri mungano, mazano ekuri kuenda ngano dzedu, nezvinoreva chemutengure senzira yemafungiro zvinobuda mutsvakurudzo ino. Chitsauko 1 ndicho chinozama kutevedza nzira yekuita tsvakurudzo inozivikanwa, asi Chitsauko 2 inyunyuto inoburitsa mukundo une chirungu sekuunzwa kwachakaitwa naCecil John Rhodes. Chitsauko 3 chinotambanudza nekujekesa kukosha kwechimbo Chemutengure, uyewo nekuti sezano, chemutengure chinotibata sei nhasi uno. Chitsauko 4 chinoronda nzira dzakafamba nadzo ngano dzekunze dzichipinda matiri, uyewo nezvakaitwa nengano dzedu pamusoro peshanduko yakanga yauya. Chitsauko 5 chinopa mienzaniso yezviteshi zvakamira ngano dzevatema padzakabva mumisha dzichienda kuzvikoro kusvika dzazove muzvimwe zvimutengure zvakadziendesa kure nasarungano. Chitsauko 6 chinotarisa dambudziko rine chirungu muhupenyu hwevanhu vatema, nekukosha kwekudada nerudzi rwedu. Chitsauko 7 chinopeta basa chichipa mazano, chichiratidza kuti ngano hadzifanire kufa nekuti dzakagara dzine simba rekufambirana nenguva. , This research is my story as a Shona folklorist and creative writer, but it is also the story of the Shona people. It is a story of how I am “a child” of storytelling, and how the stories that raised me got appropriated and incorporated into the colonial school system where they converged and mixed with western forms of storytelling to create hybrids. As a storyteller I use autoethnography – which offers an insider’s perspective - to interpret and explain, to reflect and analyse the art of storytelling in my culture. The alienation of indigenous knowledge and cultural practices – specifically storytelling, is what necessitates the use of autoethnography for this study. Autoethnography is a qualitative research method of writing and storytelling where the researcher is the subject and the researcher's experiences are the data. I, being a Shona storyteller and creative writer, will systematically journey back and analyse personal experiences in order to make sense of the Shona people’s cultural experiences. The research process will see me running away from depending on other people’s records about my people’s cultural history. Instead, I traverse back in time to consult and extract a theory from the Shona song called Chemutengure from around 1890 that tells the story of British colonisation from the perspective of the colonised. I theorise and explain Chemutengure’s pedagogical and epistemological significance in critiquing the plight of Africans suffering contact-induced change. I apply the Chemutengure theory to folktales, books, songs, paradigms and other agents that played an active role in producing new forms of storytelling and worldviews. Autoethnography is a type of research method that blends engaging creative writing and analysis of cultural experiences. It opens doors of research to the subalterns who are usually shut out by research that is done in universities. “Rather than producing esoteric, jargon-laden texts, many auto-ethnographers recognize a need to speak also to nonacademic audiences,” (Adams et al, 2015: 42) employing narrative and story-telling to give meaning to identities, relationships, and experiences, and to create relationships between past and present, researchers and participants, writers and readers, tellers and audiences, (Adams et al, 2015:23). This research will not exhaust all that needs to be explored and said about Shona folktales, creativity and culture, or its literature and the many cultural aspects it looks at. Rather, it seeks to highlight, decolonize and deconstruct colonial mentalities, while emancipating the Shona worldview that has been put on leash by colonialism and western capitalistic tendencies. The study also looks at positive change that occurs when cultures inform one another, but without turning a blind eye to the lack of mutuality and how the logic of capitalism has left Africa hemorrhaging ideologically. Drawing from personal experiences when I listened to my grandmother’s stories, the study looks at the influence of folktales on my creative writing career. I reflect on my experiences as a Fulbright Scholar, as well as my Canadian experiences as storyteller and writer-in-residence at the University of Manitoba. Besides analysing stories written by missionaries in early Shona school readers, I also discuss folktales published in the Native Affairs Department Annual (NADA); the folktales performed as songs; the comic tales published by the Literature Bureau; tales developed for private institutions, government and non-governmental organisations; stories on radio, Twitter and many other forms. Besides giving the subaltern a voice, this research attempts to artistically demonstrate the power and versatility of the Shona folktale, as well as the genre’s potential for growth and development. Chapter 1 introduces the autoethngraphy method as well as what I hope to achieve through the methodology and style of writing. Chapter 2 is a conversation between a representative of the colonised and Cecil John Rhodes the imperialist. Besides pointing out imperialism’s damage to indigenous identities, the chapter discusses how Africa and Europe’s paradigms are diametrically conflicting. Chapter 3 introduces, explains and analyses the song/theory Chemutengure, and how it applies to the condition of the native in postcolonial Africa today. Chapter 4 tracks the trajectory of foreign tales in Zimbabwe, and how they influenced native folktales. The response of local tales is also critiqued. Chapter 5 looks at the milestones in the structural transformation of indigenous folktales, and how they were appropriated and hitched a ride in the wagon of change. Chapter 6 is a reflection on the impact of westernisation and globalisation in the lives of Africans, and how confused the native has become without his cultural anchor. Chapter 7 concludes by acknowledging the inevitability of change, and suggests how cultural practices and perspectives must respond to social change so as to remain relevant.
- Full Text:
- Date Issued: 2021
- Authors: Mabasa, Ignatius T
- Date: 2021
- Subjects: Ethnology -- Zimbabwe , Zimbabwe -- Folklore , Shona (African people) -- Folklore , Ethnoscience , Decolonization in literature , Decolonization -- Africa , Autoethnography , Chemutengure , Subaltern
- Language: Shona
- Type: text , Thesis , Doctoral , PHD
- Identifier: http://hdl.handle.net/10962/174198 , vital:42454 , http://doi.org/10.21504/10962/174198
- Description: Tsvakurudzo ino inyaya yangu sasarungano nemunyori weChiShona, asiwo iri nyaya yevanhu veChiShona. Inyaya yekurerwa kwandakaitwa nengano, ndikaona ngano dzakandirera dzichipinzwa muzvikoro, dzichisangana nechirungu, dzichifambidzana nechirungu, nekuzopedzisira dzazvara mimwe misambo yengano. Basa rino maonero angu ndichishandisa nzira yetsvakurudzo inonzi husarungano, kureva muono wasarungano. Izvi zvinoreva kududzira nekutsanangura, kufungisisa nekupenengura humhizha hunowanikwa mutsika nemagariro angu, sasarungano ari kupfuurira mberi nekuita ngano munyika yazara chirungu. Naizvozvo, ini ndini musoro wenyaya yandiri kutaura, asiwo ndirini zvakare muiti wetsvakurudzo. Ndichishandisa zvandakasangana nazvo, nezvandinofunga nekuona sasarungano – ndinodzokera kuchimbo chinotaura nyaya yevaShona pakapinda vachena munyika yeZimbabwe. Ndinotsanangura zvinoreva Chemutengure, uye nekukosha kwacho mukufambisa ruzivo, mashoko nekutsanangura hupenyu hwedu sevanhu vatema vakanga vakadzvanyiriwa. Chemutengure mafungiro, imhenenguro, iyambiro nehungwaru. Ndinotsanangura ruzivo rwevanhu vangu nekushanduka kwarwo kwakakonzerwa nechirungu. Ndinoita izvi ndichipenengura ngano, mabhuku, nziyo, mafungiro nezvimwe zvimutengure zvakatakura ngano. Otoetinogirafu iyo yandichapa zita rekuti husarungano imhando yekuvhiya uchiita tsvakurudzo, uye inowanikwa pakati pehumhizha hwekunyora nyaya nekupenengura zvine chekuita nehumhizha hwetsika nemagariro evanhu. Husarungano hunovhurira musiwo vanhu vanowanzovharirwa kunze netsvakurudzo dzinoitwa mumayunivhesiti dzine mitauro isiri yavo uyewo dzimwe nguva isinganzwisisike zviri nyn’ore. Husarungano hunoshandisa rondedzero nengano kuti zvinhu zvinosanganisira hukama nezvakasanganikwa nazvo nevanhu zvinzwisisike, panguva imwechete pachiumbwa hukama pakati penguva dzakare nazvino, hukama pakati pevanoita tsvakurudzo nevavari kuita tsvakurudzo pamusoro pavo, hukama pakati pevanyori nevaverengi, vanasarungano nevateereri vengano (Adams nevamwe, 2015). Tsvakurudzo ino haisi kuzopedza zvese zvinofanira kutaurwa pamusoro pengano, tsika nemagariro evanhu vatema, kunyorwa kwemabhuku nezvimwe zvakawanda zvainobata nekutarisa, asi riripo kuratidza simba nehupfumi huri muruzivo rwevaShona rwuri kurariswa muberere memba, chirungu chichirariswa mumba. Shanduko yandiri kutarisa mubasa rino inoda kuti isu vanhu vatema tisarambe tichiverengera kuti tirongeke nekuronga mafambiro nemararamiro achaita ruzivo rwedu munyika iri kukoshesa ruzivo, maitiro nezvinhu zvinogadzirwa nevarungu. Kana tikasaronga kuti tipembedze nekuwanisa ruzivo rwedu mukana, tichaita mufakose – kurasikirwa nezvedu, nekusakwana kana kunyatsonzwisisa zvevamwe zvatiri kukoshesa. Ruzivo rwandakashandisa mubasa rino rwunosanganisira zvakaitika kwandiri kubva pandakatanga kuziva ngano dzandakaudzwa nambuya vangu, kubatsirwa kwangu nengano kuchikoro, kuve munyori wemabhuku, nekuenda kwangu mhiri kwemakungwa sasarungano. Zvakarewo ndiri kutarisa ngano dzakaunganidzwa nekunyorwa nemamishenari, ngano dzakanyorwa kare muNative Afffairs Department Annual (NADA), ngano dzakaitwa senziyo, ngano dzakaitwa neLiterature Bureau, nengano dzandave kuita dzemanon-governmental organisations (NGO), panhepfenyuro, paTwitter nezvimwe zvimutengure zvakasiyana-siyana. Hupfumi huri mungano, mazano ekuri kuenda ngano dzedu, nezvinoreva chemutengure senzira yemafungiro zvinobuda mutsvakurudzo ino. Chitsauko 1 ndicho chinozama kutevedza nzira yekuita tsvakurudzo inozivikanwa, asi Chitsauko 2 inyunyuto inoburitsa mukundo une chirungu sekuunzwa kwachakaitwa naCecil John Rhodes. Chitsauko 3 chinotambanudza nekujekesa kukosha kwechimbo Chemutengure, uyewo nekuti sezano, chemutengure chinotibata sei nhasi uno. Chitsauko 4 chinoronda nzira dzakafamba nadzo ngano dzekunze dzichipinda matiri, uyewo nezvakaitwa nengano dzedu pamusoro peshanduko yakanga yauya. Chitsauko 5 chinopa mienzaniso yezviteshi zvakamira ngano dzevatema padzakabva mumisha dzichienda kuzvikoro kusvika dzazove muzvimwe zvimutengure zvakadziendesa kure nasarungano. Chitsauko 6 chinotarisa dambudziko rine chirungu muhupenyu hwevanhu vatema, nekukosha kwekudada nerudzi rwedu. Chitsauko 7 chinopeta basa chichipa mazano, chichiratidza kuti ngano hadzifanire kufa nekuti dzakagara dzine simba rekufambirana nenguva. , This research is my story as a Shona folklorist and creative writer, but it is also the story of the Shona people. It is a story of how I am “a child” of storytelling, and how the stories that raised me got appropriated and incorporated into the colonial school system where they converged and mixed with western forms of storytelling to create hybrids. As a storyteller I use autoethnography – which offers an insider’s perspective - to interpret and explain, to reflect and analyse the art of storytelling in my culture. The alienation of indigenous knowledge and cultural practices – specifically storytelling, is what necessitates the use of autoethnography for this study. Autoethnography is a qualitative research method of writing and storytelling where the researcher is the subject and the researcher's experiences are the data. I, being a Shona storyteller and creative writer, will systematically journey back and analyse personal experiences in order to make sense of the Shona people’s cultural experiences. The research process will see me running away from depending on other people’s records about my people’s cultural history. Instead, I traverse back in time to consult and extract a theory from the Shona song called Chemutengure from around 1890 that tells the story of British colonisation from the perspective of the colonised. I theorise and explain Chemutengure’s pedagogical and epistemological significance in critiquing the plight of Africans suffering contact-induced change. I apply the Chemutengure theory to folktales, books, songs, paradigms and other agents that played an active role in producing new forms of storytelling and worldviews. Autoethnography is a type of research method that blends engaging creative writing and analysis of cultural experiences. It opens doors of research to the subalterns who are usually shut out by research that is done in universities. “Rather than producing esoteric, jargon-laden texts, many auto-ethnographers recognize a need to speak also to nonacademic audiences,” (Adams et al, 2015: 42) employing narrative and story-telling to give meaning to identities, relationships, and experiences, and to create relationships between past and present, researchers and participants, writers and readers, tellers and audiences, (Adams et al, 2015:23). This research will not exhaust all that needs to be explored and said about Shona folktales, creativity and culture, or its literature and the many cultural aspects it looks at. Rather, it seeks to highlight, decolonize and deconstruct colonial mentalities, while emancipating the Shona worldview that has been put on leash by colonialism and western capitalistic tendencies. The study also looks at positive change that occurs when cultures inform one another, but without turning a blind eye to the lack of mutuality and how the logic of capitalism has left Africa hemorrhaging ideologically. Drawing from personal experiences when I listened to my grandmother’s stories, the study looks at the influence of folktales on my creative writing career. I reflect on my experiences as a Fulbright Scholar, as well as my Canadian experiences as storyteller and writer-in-residence at the University of Manitoba. Besides analysing stories written by missionaries in early Shona school readers, I also discuss folktales published in the Native Affairs Department Annual (NADA); the folktales performed as songs; the comic tales published by the Literature Bureau; tales developed for private institutions, government and non-governmental organisations; stories on radio, Twitter and many other forms. Besides giving the subaltern a voice, this research attempts to artistically demonstrate the power and versatility of the Shona folktale, as well as the genre’s potential for growth and development. Chapter 1 introduces the autoethngraphy method as well as what I hope to achieve through the methodology and style of writing. Chapter 2 is a conversation between a representative of the colonised and Cecil John Rhodes the imperialist. Besides pointing out imperialism’s damage to indigenous identities, the chapter discusses how Africa and Europe’s paradigms are diametrically conflicting. Chapter 3 introduces, explains and analyses the song/theory Chemutengure, and how it applies to the condition of the native in postcolonial Africa today. Chapter 4 tracks the trajectory of foreign tales in Zimbabwe, and how they influenced native folktales. The response of local tales is also critiqued. Chapter 5 looks at the milestones in the structural transformation of indigenous folktales, and how they were appropriated and hitched a ride in the wagon of change. Chapter 6 is a reflection on the impact of westernisation and globalisation in the lives of Africans, and how confused the native has become without his cultural anchor. Chapter 7 concludes by acknowledging the inevitability of change, and suggests how cultural practices and perspectives must respond to social change so as to remain relevant.
- Full Text:
- Date Issued: 2021
Coastal pH variability and the eco-physiological and behavioural response of a coastal fish species in light of future ocean acidification
- Authors: Edworthy, Carla
- Date: 2021
- Subjects: Ocean acidification , Diplodus capensis (Blacktail) , Diplodus -- South Africa -- Algoa Bay , Diplodus -- Metabolism , Diplodus -- Food , Diplodus -- Larvae , Marine ecology -- South Africa -- Algoa Bay , Carbon dioxide -- Physiological effect , Respiration -- Measurement
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/176793 , vital:42759 , 10.21504/10962/176793
- Description: Ocean acidification (OA) is a global phenomenon referring to a decrease in ocean pH and a perturbation of the seawater carbonate system due to ever-increasing atmospheric CO2 concentrations. In coastal environments, identifying the impacts of OA is complex due to the multiple contributors to pH variability by coastal processes, such as freshwater inflow, upwelling, hydrodynamic processes, and biological activity. The aim of this PhD study was to quantify the local processes occurring in a temperate coastal embayment, Algoa Bay in South Africa, that contribute to pH and carbonate chemistry variability over time (monthly and 24-hour) and space (~10 km) and examine how this variability impacts a local fish species, Diplodus capensis, also commonly known as ‘blacktail’. Algoa Bay, known for its complex oceanography, is an interesting location in which to quantify carbonate chemistry variability. To assess this variability, monitoring sites were selected to coincide with the Algoa Bay Sentinel Site long-term ecological research (LTER) and continuous monitoring (CMP) programmes. The average pH at offshore sites in the bay was 8.03 ± 0.07 and at inshore sites was 8.04 ± 0.15. High pH variability (~0.55–0.61 pH units) was recorded at both offshore (>10 m depth) and inshore sites (intertidal surf zones). Many sites in the bay, especially the atypical site at Cape Recife, exhibit higher than the average pH levels (>8.04), suggesting that pH variability may be biologically driven. This is further evidenced by high diurnal variability in pH (~0.55 pH units). Although the specific drivers of the high pH variability in Algoa Bay could not be identified, baseline carbonate chemistry conditions were identified, which is necessary information to design and interpret biological experiments. Long-term, continuous monitoring is required to improve understanding of the drivers of pH variability in understudied coastal regions, like Algoa Bay. A local fisheries species, D. capensis, was selected as a model species to assess the impacts of future OA scenarios in Algoa Bay. It was hypothesized that this temperate, coastally distributed species would be adapted to naturally variable pH conditions and thus show some tolerance to low pH, considering that they are exposed to minimum pH levels of 7.77 and fluctuations of up to 0.55 pH units. Laboratory perturbation experiments were used to expose early postflexion stage of D. capensis to a range of pH treatments that were selected based on the measured local variability (~8.0–7.7 pH), as well as future projected OA scenarios (7.6–7.2 pH). Physiological responses were estimated using intermittent flow respirometry by quantifying routine and active metabolic rates as well as relative aerobic scope at each pH treatment. The behavioural responses of the larvae were also assessed at each pH treatment, as activity levels, by measuring swimming distance and speed in video-recording experiments, as well as feeding rates. D. capensis had sufficient physiological capacity to maintain metabolic performance at pH levels as low as 7.27, as evidenced by no changes in any of the measured metabolic rates (routine metabolic rate, active metabolic rate, and relative aerobic scope) after exposure to the range of pH treatments (8.02–7.27). Feeding rates of D. capensis were similarly unaffected by pH treatment. However, it appears that subtle increases in activity level (measured by swimming distance and swimming speed experiments) occur with a decrease in pH. These changes in activity level were a consequence of a change in behaviour rather than metabolic constraints. This study concludes, however, that based on the parameters measured, there is no evidence for survival or fitness related consequences of near future OA on D. capensis. OA research is still in its infancy in South Africa, and the potential impacts of OA to local marine resources has not yet been considered in local policy and resource management strategies. Integrating field monitoring and laboratory perturbation experiments is emerging as best practice in OA research. This is the first known study on the temperate south coast of South Africa to quantify local pH variability and to use this information to evaluate the biological response of a local species using relevant local OA scenarios as treatment levels for current and near future conditions. Research on local conditions in situ and the potential impacts of future OA scenarios on socio-economically valuable species, following the model developed in this study, is necessary to provide national policy makers with relevant scientific data to inform climate change management policies for local resources.
- Full Text:
- Date Issued: 2021
- Authors: Edworthy, Carla
- Date: 2021
- Subjects: Ocean acidification , Diplodus capensis (Blacktail) , Diplodus -- South Africa -- Algoa Bay , Diplodus -- Metabolism , Diplodus -- Food , Diplodus -- Larvae , Marine ecology -- South Africa -- Algoa Bay , Carbon dioxide -- Physiological effect , Respiration -- Measurement
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/176793 , vital:42759 , 10.21504/10962/176793
- Description: Ocean acidification (OA) is a global phenomenon referring to a decrease in ocean pH and a perturbation of the seawater carbonate system due to ever-increasing atmospheric CO2 concentrations. In coastal environments, identifying the impacts of OA is complex due to the multiple contributors to pH variability by coastal processes, such as freshwater inflow, upwelling, hydrodynamic processes, and biological activity. The aim of this PhD study was to quantify the local processes occurring in a temperate coastal embayment, Algoa Bay in South Africa, that contribute to pH and carbonate chemistry variability over time (monthly and 24-hour) and space (~10 km) and examine how this variability impacts a local fish species, Diplodus capensis, also commonly known as ‘blacktail’. Algoa Bay, known for its complex oceanography, is an interesting location in which to quantify carbonate chemistry variability. To assess this variability, monitoring sites were selected to coincide with the Algoa Bay Sentinel Site long-term ecological research (LTER) and continuous monitoring (CMP) programmes. The average pH at offshore sites in the bay was 8.03 ± 0.07 and at inshore sites was 8.04 ± 0.15. High pH variability (~0.55–0.61 pH units) was recorded at both offshore (>10 m depth) and inshore sites (intertidal surf zones). Many sites in the bay, especially the atypical site at Cape Recife, exhibit higher than the average pH levels (>8.04), suggesting that pH variability may be biologically driven. This is further evidenced by high diurnal variability in pH (~0.55 pH units). Although the specific drivers of the high pH variability in Algoa Bay could not be identified, baseline carbonate chemistry conditions were identified, which is necessary information to design and interpret biological experiments. Long-term, continuous monitoring is required to improve understanding of the drivers of pH variability in understudied coastal regions, like Algoa Bay. A local fisheries species, D. capensis, was selected as a model species to assess the impacts of future OA scenarios in Algoa Bay. It was hypothesized that this temperate, coastally distributed species would be adapted to naturally variable pH conditions and thus show some tolerance to low pH, considering that they are exposed to minimum pH levels of 7.77 and fluctuations of up to 0.55 pH units. Laboratory perturbation experiments were used to expose early postflexion stage of D. capensis to a range of pH treatments that were selected based on the measured local variability (~8.0–7.7 pH), as well as future projected OA scenarios (7.6–7.2 pH). Physiological responses were estimated using intermittent flow respirometry by quantifying routine and active metabolic rates as well as relative aerobic scope at each pH treatment. The behavioural responses of the larvae were also assessed at each pH treatment, as activity levels, by measuring swimming distance and speed in video-recording experiments, as well as feeding rates. D. capensis had sufficient physiological capacity to maintain metabolic performance at pH levels as low as 7.27, as evidenced by no changes in any of the measured metabolic rates (routine metabolic rate, active metabolic rate, and relative aerobic scope) after exposure to the range of pH treatments (8.02–7.27). Feeding rates of D. capensis were similarly unaffected by pH treatment. However, it appears that subtle increases in activity level (measured by swimming distance and swimming speed experiments) occur with a decrease in pH. These changes in activity level were a consequence of a change in behaviour rather than metabolic constraints. This study concludes, however, that based on the parameters measured, there is no evidence for survival or fitness related consequences of near future OA on D. capensis. OA research is still in its infancy in South Africa, and the potential impacts of OA to local marine resources has not yet been considered in local policy and resource management strategies. Integrating field monitoring and laboratory perturbation experiments is emerging as best practice in OA research. This is the first known study on the temperate south coast of South Africa to quantify local pH variability and to use this information to evaluate the biological response of a local species using relevant local OA scenarios as treatment levels for current and near future conditions. Research on local conditions in situ and the potential impacts of future OA scenarios on socio-economically valuable species, following the model developed in this study, is necessary to provide national policy makers with relevant scientific data to inform climate change management policies for local resources.
- Full Text:
- Date Issued: 2021
Defended subjectivity in service-learning:a psychosocial analysis of students’ talk about service-learning in psychology
- Authors: Haselau, Tracey Laura
- Date: 2021
- Subjects: Service learning -- Case studies -- South Africa -- Makhanda , Rhodes University -- Students -- Attitudes , Psychology students -- Attitudes -- South Africa -- Makhanda
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/170810 , vital:41962 , 10.21504/10962/170810
- Description: The purpose of this qualitative study was to analyse students’ talk about their service-learning experiences in psychology, in South Africa, from a psychosocial perspective. The research aims to identify dominant and subjugated discourses about service-learning in psychology, and to explore why students invest in particular discourses over others. Furthermore, the research aims to explore the intersubjective contexts that mediate students’ talk about their service-learning and their emotional investments in the discourses employed in their talk, drawing on the concept of mentalization. Eight psychology students were interviewed toward the end of their participation in a service-learning psychology honours course. Transcripts from the interviews as well as entries from students’ reflective journals were analysed using a psychosocial methodology. The key findings from this research point to the ways in which students oscillate between employing two competing sets of discourses about their service learning. At times, students drew on what I have referred to as a ‘discourse of rapture’, characterised by fascination with the ‘other’ and the maintenance of power imbalances. This discourse draws on a liberal traditional discourse of learning and a charity discourse of service-learning. In other parts of their talk, students draw on what I have called a ‘discourse of ruptura’, characterised by an inward curiosity about the outward fascination with the ‘other’. This discourse draws on constructivist accounts of service-learning. Findings suggest that students’ emotional investments in discourses of service-learning are mediated by defensive positions caused by the anxieties incurred in service-learning contexts. An important consideration to take forward from this research is the way in which anxieties in service-learning experiences may be contained (or not), and to be aware of the problematic outcomes that may arise from not containing anxieties, such as the perpetuation of prejudicial attitudes and othering. The intersectionality of ‘race’ and disability in the specific service-learning programme under investigation in this study is an important consideration in implementing careful supervision of programmes such as this one, so that students’ rapture with the ‘other’ is not compounded and reinforced by the service-learning experience.
- Full Text:
- Date Issued: 2021
- Authors: Haselau, Tracey Laura
- Date: 2021
- Subjects: Service learning -- Case studies -- South Africa -- Makhanda , Rhodes University -- Students -- Attitudes , Psychology students -- Attitudes -- South Africa -- Makhanda
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/170810 , vital:41962 , 10.21504/10962/170810
- Description: The purpose of this qualitative study was to analyse students’ talk about their service-learning experiences in psychology, in South Africa, from a psychosocial perspective. The research aims to identify dominant and subjugated discourses about service-learning in psychology, and to explore why students invest in particular discourses over others. Furthermore, the research aims to explore the intersubjective contexts that mediate students’ talk about their service-learning and their emotional investments in the discourses employed in their talk, drawing on the concept of mentalization. Eight psychology students were interviewed toward the end of their participation in a service-learning psychology honours course. Transcripts from the interviews as well as entries from students’ reflective journals were analysed using a psychosocial methodology. The key findings from this research point to the ways in which students oscillate between employing two competing sets of discourses about their service learning. At times, students drew on what I have referred to as a ‘discourse of rapture’, characterised by fascination with the ‘other’ and the maintenance of power imbalances. This discourse draws on a liberal traditional discourse of learning and a charity discourse of service-learning. In other parts of their talk, students draw on what I have called a ‘discourse of ruptura’, characterised by an inward curiosity about the outward fascination with the ‘other’. This discourse draws on constructivist accounts of service-learning. Findings suggest that students’ emotional investments in discourses of service-learning are mediated by defensive positions caused by the anxieties incurred in service-learning contexts. An important consideration to take forward from this research is the way in which anxieties in service-learning experiences may be contained (or not), and to be aware of the problematic outcomes that may arise from not containing anxieties, such as the perpetuation of prejudicial attitudes and othering. The intersectionality of ‘race’ and disability in the specific service-learning programme under investigation in this study is an important consideration in implementing careful supervision of programmes such as this one, so that students’ rapture with the ‘other’ is not compounded and reinforced by the service-learning experience.
- Full Text:
- Date Issued: 2021
Design patterns and software techniques for large-scale, open and reproducible data reduction
- Authors: Molenaar, Gijs Jan
- Date: 2021
- Subjects: Radio astronomy -- Data processing , Radio astronomy -- Data processing -- Software , Radio astronomy -- South Africa , ASTRODECONV2019 dataset , Radio telescopes -- South Africa , KERN (omputer software)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172169 , vital:42172 , 10.21504/10962/172169
- Description: The preparation for the construction of the Square Kilometre Array, and the introduction of its operational precursors, such as LOFAR and MeerKAT, mark the beginning of an exciting era for astronomy. Impressive new data containing valuable science just waiting for discovery is already being generated, and these devices will produce far more data than has ever been collected before. However, with every new data instrument, the data rates grow to unprecedented quantities of data, requiring novel new data-processing tools. In addition, creating science grade data from the raw data still requires significant expert knowledge for processing this data. The software used is often developed by a scientist who lacks proper training in software development skills, resulting in the software not progressing beyond a prototype stage in quality. In the first chapter, we explore various organisational and technical approaches to address these issues by providing a historical overview of the development of radioastronomy pipelines since the inception of the field in the 1940s. In that, the steps required to create a radio image are investigated. We used the lessons-learned to identify patterns in the challenges experienced, and the solutions created to address these over the years. The second chapter describes the mathematical foundations that are essential for radio imaging. In the third chapter, we discuss the production of the KERN Linux distribution, which is a set of software packages containing most radio astronomy software currently in use. Considerable effort was put into making sure that the contained software installs appropriately, all items next to one other on the same system. Where required and possible, bugs and portability fixes were solved and reported with the upstream maintainers. The KERN project also has a website, and issue tracker, where users can report bugs and maintainers can coordinate the packaging effort and new releases. The software packages can be used inside Docker and Singularity containers, enabling the installation of these packages on a wide variety of platforms. In the fourth and fifth chapters, we discuss methods and frameworks for combining the available data reduction tools into recomposable pipelines and introduce the Kliko specification and software. This framework was created to enable end-user astronomers to chain and containerise operations of software in KERN packages. Next, we discuss the Common Workflow Language (CommonWL), a similar but more advanced and mature pipeline framework invented by bio-informatics scientists. CommonWL is supported by a wide range of tools already; among other schedulers, visualisers and editors. Consequently, when a pipeline is made with CommonWL, it can be deployed and manipulated with a wide range of tools. In the final chapter, we attempt something unconventional, applying a generative adversarial network based on deep learning techniques to perform the task of sky brightness reconstruction. Since deep learning methods often require a large number of training samples, we constructed a CommonWL simulation pipeline for creating dirty images and corresponding sky models. This simulated dataset has been made publicly available as the ASTRODECONV2019 dataset. It is shown that this method is useful to perform the restoration and matches the performance of a single clean cycle. In addition, we incorporated domain knowledge by adding the point spread function to the network and by utilising a custom loss function during training. Although it was not possible to improve the cleaning performance of commonly used existing tools, the computational time performance of the approach looks very promising. We suggest that a smaller scope should be the starting point for further studies and optimising of the training of the neural network could produce the desired results.
- Full Text:
- Date Issued: 2021
- Authors: Molenaar, Gijs Jan
- Date: 2021
- Subjects: Radio astronomy -- Data processing , Radio astronomy -- Data processing -- Software , Radio astronomy -- South Africa , ASTRODECONV2019 dataset , Radio telescopes -- South Africa , KERN (omputer software)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172169 , vital:42172 , 10.21504/10962/172169
- Description: The preparation for the construction of the Square Kilometre Array, and the introduction of its operational precursors, such as LOFAR and MeerKAT, mark the beginning of an exciting era for astronomy. Impressive new data containing valuable science just waiting for discovery is already being generated, and these devices will produce far more data than has ever been collected before. However, with every new data instrument, the data rates grow to unprecedented quantities of data, requiring novel new data-processing tools. In addition, creating science grade data from the raw data still requires significant expert knowledge for processing this data. The software used is often developed by a scientist who lacks proper training in software development skills, resulting in the software not progressing beyond a prototype stage in quality. In the first chapter, we explore various organisational and technical approaches to address these issues by providing a historical overview of the development of radioastronomy pipelines since the inception of the field in the 1940s. In that, the steps required to create a radio image are investigated. We used the lessons-learned to identify patterns in the challenges experienced, and the solutions created to address these over the years. The second chapter describes the mathematical foundations that are essential for radio imaging. In the third chapter, we discuss the production of the KERN Linux distribution, which is a set of software packages containing most radio astronomy software currently in use. Considerable effort was put into making sure that the contained software installs appropriately, all items next to one other on the same system. Where required and possible, bugs and portability fixes were solved and reported with the upstream maintainers. The KERN project also has a website, and issue tracker, where users can report bugs and maintainers can coordinate the packaging effort and new releases. The software packages can be used inside Docker and Singularity containers, enabling the installation of these packages on a wide variety of platforms. In the fourth and fifth chapters, we discuss methods and frameworks for combining the available data reduction tools into recomposable pipelines and introduce the Kliko specification and software. This framework was created to enable end-user astronomers to chain and containerise operations of software in KERN packages. Next, we discuss the Common Workflow Language (CommonWL), a similar but more advanced and mature pipeline framework invented by bio-informatics scientists. CommonWL is supported by a wide range of tools already; among other schedulers, visualisers and editors. Consequently, when a pipeline is made with CommonWL, it can be deployed and manipulated with a wide range of tools. In the final chapter, we attempt something unconventional, applying a generative adversarial network based on deep learning techniques to perform the task of sky brightness reconstruction. Since deep learning methods often require a large number of training samples, we constructed a CommonWL simulation pipeline for creating dirty images and corresponding sky models. This simulated dataset has been made publicly available as the ASTRODECONV2019 dataset. It is shown that this method is useful to perform the restoration and matches the performance of a single clean cycle. In addition, we incorporated domain knowledge by adding the point spread function to the network and by utilising a custom loss function during training. Although it was not possible to improve the cleaning performance of commonly used existing tools, the computational time performance of the approach looks very promising. We suggest that a smaller scope should be the starting point for further studies and optimising of the training of the neural network could produce the desired results.
- Full Text:
- Date Issued: 2021
Elucidating Tuta absoluta (Meyrick) invasion and enhancing its management in Eastern Africa : spread, socio-ecological impacts, and potential of a newly imported larval parasitoid for classical biological control Eastern in Africa
- Aigbedion-Atalor, Pascal Osabhahiemen
- Authors: Aigbedion-Atalor, Pascal Osabhahiemen
- Date: 2021
- Subjects: Tuta absoluta -- Biological control , Tomatoes -- Diseases and pests -- Africa, East , Braconidae , Gelechiidae -- Biological control -- Africa, East , Insects as biological pest control agents -- Africa, East
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/170421 , vital:41920 , 10.21504/10962/170421
- Description: Agriculture is a fundamental source of sustainable livelihoods in sub-Saharan Africa and millions of people in the region rely solely on small-scale farming for their food security. However, the impacts of invasive alien species (IAS) on crop production are serious, and there is no sign of this abating. Among the recent IAS that have invaded Africa in the last decade, the South American tomato pinworm Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) has been one of the most damaging. Following its first record in the Maghreb region of Africa in 2008, T. absoluta rapidly spread throughout Africa with substantial impacts on tomato production, often causing 100% yield loss. Management options adopted against T. absoluta by tomato growers in Africa have been based on the use of synthetic insecticides. While chemical insecticide applications are an important component of an integrated pest management programme, misuse and over-reliance often exacerbates the impacts of T. absolutadue to the development of resistance to commonly used active substances, increasing the fitness of the pest. This thesis sought to understand the socio-economic impacts of the spread of T. absoluta in Eastern Africa and provide effective sustainable pest management strategies to reduce its impacts below economic thresholds. Mapping surveys of Tabsoluta were conducted in 226 tomato agro-ecosystems across four eastern countries (Kenya, Sudan, Tanzania, and Uganda) Eastern Africa from 2016 to 2018 to determine the spatiotemporal distribution of the pest. The impacts of T. absoluta on the livelihoods of tomato growers were also assessed. Here, 200 tomato growers in Kenya were interviewed using a semi-structured questionnaire. Although T. absoluta, a recent invader, was distributed at high infestation levels throughout the subregion (all four countries) and was considered as the most damaging invasive alien species of agriculturally sustainable livelihoods. The arrival of T. absoluta in the subregion has resulted in livelihood losses and increased the cost of tomato production and price of the fruit, and the frequency of pesticide applications. The impact of this pest and the and the absence of effective indigenous natural enemies of the pest in Eastern Africa, was the rationale for the importation of a larval parasitoid, Dolichogenidea gelechiidivoris Marsh Syn.: Apanteles gelechiidivoris Marsh) (Hymenoptera: Braconidae), of T. absoluta from Peru into the quarantine facility of the International Centre of Insect Physiology and ecologyz(icipe), in Kenya. Pre-release assessments on the parasitzation potential of D. gelechiidivoris, encompassing host larval preference and the host suitability, and its reproductive strategy, for classical biological control of T. absoluta in Africa were conducted. Dolichogenidea gelechiidivoris females preferentially oviposited in early (1st and 2nd) larval instars of T. absoluta but parasitized and completed development in all four instars of the host. Host instar did not affect D. gelechiidivoris sex-ratio but females reared on the first instar had significantly fewer eggs than when reared in late larval instars (3rd and 4th). Females of the parasitoid emerged with a high mature egg load which peaked 2 d post-eclosion. The females of D. gelechiidivoris survived 8.51±0.65 d and produced 103±8 offspring per female at 26±4°C (range: 24 to 29°C) and 50–70% relative humidity (RH) in the presence of males and fed honey-water (80% honey). Increasing maternal age decreased the proportion of female offspring. Under the aforementioned laboratory conditions, the Gross and Net reproductive rates were 72 and 39.5 respectively, while the mean generation time was 20 d. The estimated intrinsic rate of natural increase was 0.18. These findings indicate that D. gelechiidivorisis a potential biological control agent of T. absoluta and should be considered for augmentative/inundative release in Kenya and across Africa following host specificity testing and risk assessments. The nature of the interaction between D. gelechidivoris and the predatory mirid bug Nesidiocoris tenuis(Reuter) (Hemiptera: Miridae), an important and widespread natural enemy of T. absoluta in Africa was evaluated because N. tenuis, although being a voracious predator of T. absoluta eggs, it can also prey on the early host larval instars (1st and 2nd) which are the preferred oviposition host stages of D. gelechiidivoris. Here, the impact of N. tenuis feeding on T. absoluta and the effects on D. gelechiidivoris performance was tested. Regardless of the order of introductions (i.e. the sequence of combination with D. gelechiidivoris) and densities (i.e. number of N. tenuis combined with D. gelechiidivoris), there was no intraguild predation by N. tenuis on D. gelechiidivorisas there was little host larval feeding behaviour. Also, the presence of N. tenuis did not affect the oviposition performance of D. gelechiidivoris. Further investigations revealed that the combined efficacy of N. tenuis and D. gelechiidivorison T. absoluta population was significantly higher than either natural enemy alone, thus contributes to the data supporting the release of D. gelechiidivoris in Africa. In concluding, integrating D. gelechiidivoris and N. tenuis in the management of T. absolut could potentially reduce yield losses in tomato in Eastern Africa where the socio-economic impacts of the pest are very serious.
- Full Text:
- Date Issued: 2021
- Authors: Aigbedion-Atalor, Pascal Osabhahiemen
- Date: 2021
- Subjects: Tuta absoluta -- Biological control , Tomatoes -- Diseases and pests -- Africa, East , Braconidae , Gelechiidae -- Biological control -- Africa, East , Insects as biological pest control agents -- Africa, East
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/170421 , vital:41920 , 10.21504/10962/170421
- Description: Agriculture is a fundamental source of sustainable livelihoods in sub-Saharan Africa and millions of people in the region rely solely on small-scale farming for their food security. However, the impacts of invasive alien species (IAS) on crop production are serious, and there is no sign of this abating. Among the recent IAS that have invaded Africa in the last decade, the South American tomato pinworm Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) has been one of the most damaging. Following its first record in the Maghreb region of Africa in 2008, T. absoluta rapidly spread throughout Africa with substantial impacts on tomato production, often causing 100% yield loss. Management options adopted against T. absoluta by tomato growers in Africa have been based on the use of synthetic insecticides. While chemical insecticide applications are an important component of an integrated pest management programme, misuse and over-reliance often exacerbates the impacts of T. absolutadue to the development of resistance to commonly used active substances, increasing the fitness of the pest. This thesis sought to understand the socio-economic impacts of the spread of T. absoluta in Eastern Africa and provide effective sustainable pest management strategies to reduce its impacts below economic thresholds. Mapping surveys of Tabsoluta were conducted in 226 tomato agro-ecosystems across four eastern countries (Kenya, Sudan, Tanzania, and Uganda) Eastern Africa from 2016 to 2018 to determine the spatiotemporal distribution of the pest. The impacts of T. absoluta on the livelihoods of tomato growers were also assessed. Here, 200 tomato growers in Kenya were interviewed using a semi-structured questionnaire. Although T. absoluta, a recent invader, was distributed at high infestation levels throughout the subregion (all four countries) and was considered as the most damaging invasive alien species of agriculturally sustainable livelihoods. The arrival of T. absoluta in the subregion has resulted in livelihood losses and increased the cost of tomato production and price of the fruit, and the frequency of pesticide applications. The impact of this pest and the and the absence of effective indigenous natural enemies of the pest in Eastern Africa, was the rationale for the importation of a larval parasitoid, Dolichogenidea gelechiidivoris Marsh Syn.: Apanteles gelechiidivoris Marsh) (Hymenoptera: Braconidae), of T. absoluta from Peru into the quarantine facility of the International Centre of Insect Physiology and ecologyz(icipe), in Kenya. Pre-release assessments on the parasitzation potential of D. gelechiidivoris, encompassing host larval preference and the host suitability, and its reproductive strategy, for classical biological control of T. absoluta in Africa were conducted. Dolichogenidea gelechiidivoris females preferentially oviposited in early (1st and 2nd) larval instars of T. absoluta but parasitized and completed development in all four instars of the host. Host instar did not affect D. gelechiidivoris sex-ratio but females reared on the first instar had significantly fewer eggs than when reared in late larval instars (3rd and 4th). Females of the parasitoid emerged with a high mature egg load which peaked 2 d post-eclosion. The females of D. gelechiidivoris survived 8.51±0.65 d and produced 103±8 offspring per female at 26±4°C (range: 24 to 29°C) and 50–70% relative humidity (RH) in the presence of males and fed honey-water (80% honey). Increasing maternal age decreased the proportion of female offspring. Under the aforementioned laboratory conditions, the Gross and Net reproductive rates were 72 and 39.5 respectively, while the mean generation time was 20 d. The estimated intrinsic rate of natural increase was 0.18. These findings indicate that D. gelechiidivorisis a potential biological control agent of T. absoluta and should be considered for augmentative/inundative release in Kenya and across Africa following host specificity testing and risk assessments. The nature of the interaction between D. gelechidivoris and the predatory mirid bug Nesidiocoris tenuis(Reuter) (Hemiptera: Miridae), an important and widespread natural enemy of T. absoluta in Africa was evaluated because N. tenuis, although being a voracious predator of T. absoluta eggs, it can also prey on the early host larval instars (1st and 2nd) which are the preferred oviposition host stages of D. gelechiidivoris. Here, the impact of N. tenuis feeding on T. absoluta and the effects on D. gelechiidivoris performance was tested. Regardless of the order of introductions (i.e. the sequence of combination with D. gelechiidivoris) and densities (i.e. number of N. tenuis combined with D. gelechiidivoris), there was no intraguild predation by N. tenuis on D. gelechiidivorisas there was little host larval feeding behaviour. Also, the presence of N. tenuis did not affect the oviposition performance of D. gelechiidivoris. Further investigations revealed that the combined efficacy of N. tenuis and D. gelechiidivorison T. absoluta population was significantly higher than either natural enemy alone, thus contributes to the data supporting the release of D. gelechiidivoris in Africa. In concluding, integrating D. gelechiidivoris and N. tenuis in the management of T. absolut could potentially reduce yield losses in tomato in Eastern Africa where the socio-economic impacts of the pest are very serious.
- Full Text:
- Date Issued: 2021