Land use/cover change modelling and land degradation assessment in the Keiskamma catchment using remote sensing and GIS
- Authors: Mhangara, Paidamwoyo
- Date: 2011
- Subjects: Land use -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Keiskamma River (South Africa)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10647 , http://hdl.handle.net/10948/1467 , Land use -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Keiskamma River (South Africa)
- Description: Land degradation in most communal parts of the Keiskamma catchment has reached alarming proportions. The Keiskamma catchment is particularly predisposed to severe land degradation associated with soil erosion, thicket degradation and deteriorating riparian vegetation. There is a close coupling between land use/cover dynamics and degradation trends witnessed in the catchment. Soil erosion is prevalent in most of the communal areas in the catchment. The principal aim of this study was to investigate land use/cover trends, model the spatial patterns of soil loss and predict future land use/cover scenarios as a means of assessing land degradation in the Keiskamma catchment. Multi-temporal Landsat satellite imagery from 1972 to 2006 was used for land use/cover change analyses using object-oriented post-classification comparison. Fragmentation analysis was performed by computing and analyzing landscape metrics in the riparian and adjacent hillslope areas to determine the land cover structural changes that have occurred since 1972. The landscape function analysis was used to validate the current rangeland conditions in the communal areas and the former commercial farms. The current condition of the riparian zones and proximal hillslopes was assessed using the Rapid Appraisal of Riparian Condition and future land use/cover scenarios were simulated using the Markovcellular automata model. Spatial patterns of soil loss in the Keiskamma catchment were determined using the Sediment Assessment Tool for Effective Erosion Control (SATEEC), which is a GIS based RUSLE model that integrates sediment delivery ratios. Object oriented classification was used to map soil erosion surfaces and valley infill in ephemeral stream channels as a means of demonstrating the major sediment transfer processes operating in the Keiskamma catchment. The Mahalanobis distance method was used to compute the topographic thresholds for gully erosion. To understand the effect of soil characteristics in severe forms of erosion, laboratory analyses were undertaken to determine the physico-chemical soil properties. iv The temporal land use/cover analysis done using the post-classification change detection indicated that intact vegetation has undergone a significant decline from 1972 to 2006. The temporal changes within the intermediate years are characterized by cyclic transitions of decline and recovery of intact vegetation. An overall decline in intact vegetation cover, an increase in degraded vegetation and bare eroded soil was noted. Fragmentation analyses done in the communal villages of the central Keiskamma catchment indicated increasing vegetation fragmentation manifested by an increase in smaller and less connected vegetation patches, and a subsequent increase of bare and degraded soil patches which are much bigger and more connected. The Landscape Organisation Index revealed very low vegetation connectivity in the communal rangelands that have weak local traditional institutions. Fragmentation analyses in the riparian and proximal hillslopes revealed evidence of increasing vegetation fragmentation from 1972 to 2006. The Markov Cellular Automata simulation predicted a decline in intact vegetation and an increase in bare and degraded soil in 2019. The Keiskamma catchment was noted as experiencing high rates of soil loss that are above provincial and national averages. The classification of erosion features and valley infill showcased the vegetation enrichment in the ephemeral streams which is occurring at the expense of high soil losses from severe gully erosion on the hillslopes. This in turn has led to an inversion of grazing patterns within the catchment, such that grazing is now concentrated within the ephemeral stream channels. Soil chemical analyses revealed a high sodium content and low soluble salt concentration, which promote soil dispersion, piping and gully erosion. The presence of high amounts of illite-smectite in the catchment also accounts for the highly dispersive nature of the soil even at low SAR values. Significant amounts of swelling 2:1 silicate clays such as smectites cause cracking and contribute to the development of piping and gullying in the catchment. Given the worsening degradation trends in the communal areas, a systematic re-allocation of state land in sections of the catchment that belonged to the former commercial farms is recommended to alleviate anthropogenic pressure. Strengthening local institutions that effectively monitor and manage natural resources will be required in order to maintain v optimum flow regimes in rivers and curb thicket degradation. Measures to curb environmental degradation in the Keiskamma catchment should encompass suitable ecological interventions that are sensitive to the socio-economic challenges facing the people in communal areas.
- Full Text:
- Date Issued: 2011
- Authors: Mhangara, Paidamwoyo
- Date: 2011
- Subjects: Land use -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Keiskamma River (South Africa)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10647 , http://hdl.handle.net/10948/1467 , Land use -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Keiskamma River (South Africa)
- Description: Land degradation in most communal parts of the Keiskamma catchment has reached alarming proportions. The Keiskamma catchment is particularly predisposed to severe land degradation associated with soil erosion, thicket degradation and deteriorating riparian vegetation. There is a close coupling between land use/cover dynamics and degradation trends witnessed in the catchment. Soil erosion is prevalent in most of the communal areas in the catchment. The principal aim of this study was to investigate land use/cover trends, model the spatial patterns of soil loss and predict future land use/cover scenarios as a means of assessing land degradation in the Keiskamma catchment. Multi-temporal Landsat satellite imagery from 1972 to 2006 was used for land use/cover change analyses using object-oriented post-classification comparison. Fragmentation analysis was performed by computing and analyzing landscape metrics in the riparian and adjacent hillslope areas to determine the land cover structural changes that have occurred since 1972. The landscape function analysis was used to validate the current rangeland conditions in the communal areas and the former commercial farms. The current condition of the riparian zones and proximal hillslopes was assessed using the Rapid Appraisal of Riparian Condition and future land use/cover scenarios were simulated using the Markovcellular automata model. Spatial patterns of soil loss in the Keiskamma catchment were determined using the Sediment Assessment Tool for Effective Erosion Control (SATEEC), which is a GIS based RUSLE model that integrates sediment delivery ratios. Object oriented classification was used to map soil erosion surfaces and valley infill in ephemeral stream channels as a means of demonstrating the major sediment transfer processes operating in the Keiskamma catchment. The Mahalanobis distance method was used to compute the topographic thresholds for gully erosion. To understand the effect of soil characteristics in severe forms of erosion, laboratory analyses were undertaken to determine the physico-chemical soil properties. iv The temporal land use/cover analysis done using the post-classification change detection indicated that intact vegetation has undergone a significant decline from 1972 to 2006. The temporal changes within the intermediate years are characterized by cyclic transitions of decline and recovery of intact vegetation. An overall decline in intact vegetation cover, an increase in degraded vegetation and bare eroded soil was noted. Fragmentation analyses done in the communal villages of the central Keiskamma catchment indicated increasing vegetation fragmentation manifested by an increase in smaller and less connected vegetation patches, and a subsequent increase of bare and degraded soil patches which are much bigger and more connected. The Landscape Organisation Index revealed very low vegetation connectivity in the communal rangelands that have weak local traditional institutions. Fragmentation analyses in the riparian and proximal hillslopes revealed evidence of increasing vegetation fragmentation from 1972 to 2006. The Markov Cellular Automata simulation predicted a decline in intact vegetation and an increase in bare and degraded soil in 2019. The Keiskamma catchment was noted as experiencing high rates of soil loss that are above provincial and national averages. The classification of erosion features and valley infill showcased the vegetation enrichment in the ephemeral streams which is occurring at the expense of high soil losses from severe gully erosion on the hillslopes. This in turn has led to an inversion of grazing patterns within the catchment, such that grazing is now concentrated within the ephemeral stream channels. Soil chemical analyses revealed a high sodium content and low soluble salt concentration, which promote soil dispersion, piping and gully erosion. The presence of high amounts of illite-smectite in the catchment also accounts for the highly dispersive nature of the soil even at low SAR values. Significant amounts of swelling 2:1 silicate clays such as smectites cause cracking and contribute to the development of piping and gullying in the catchment. Given the worsening degradation trends in the communal areas, a systematic re-allocation of state land in sections of the catchment that belonged to the former commercial farms is recommended to alleviate anthropogenic pressure. Strengthening local institutions that effectively monitor and manage natural resources will be required in order to maintain v optimum flow regimes in rivers and curb thicket degradation. Measures to curb environmental degradation in the Keiskamma catchment should encompass suitable ecological interventions that are sensitive to the socio-economic challenges facing the people in communal areas.
- Full Text:
- Date Issued: 2011
An examination of international trophy hunters' South African hunting experiences
- Authors: Han, Xiliang
- Date: 2010
- Subjects: Hunting trophies -- South Africa , Big game hunting -- South Africa , Big game animals -- South Africa , Safaris -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9362 , http://hdl.handle.net/10948/1244 , Hunting trophies -- South Africa , Big game hunting -- South Africa , Big game animals -- South Africa , Safaris -- South Africa
- Description: The diversity of wildlife resources and the highly-developed trophy hunting and game ranching industry make South Africa a sought-after destination for travelling hunters. Significant economic, social and ecological benefits result from the annual visits of 16 000 hunters. These benefits, in turn, accelerate industry competition. To maintain or increase the clientele base, hunting providers should continue to manage and improve their clients’ safari experiences. This research investigated visiting hunters’ South African safari experiences by measuring their perceptions of service quality, satisfaction and behavioural intention. The results of the research could assist hunting providers in identifying areas where service expectations are not met and understanding the impact of service quality and satisfaction on clients’ loyalty. The literature study contextualised the South African trophy hunting industry within the tourism environment, the realms of wildlife tourism, and the characteristics of hunting tourism. An overview of tourism services, service quality, customer satisfaction, and behavioural intention was also provided. The resulting conceptual model hypothesised relationships among the safari experience variables (service quality, satisfaction and behavioural intention). ii The empirical data were collected by means of a mail survey, using a self-administered questionnaire distributed to 2 000 foreign hunters who had participated in a South African hunting safari at least once between 2003 and 2007. Two hundred and thirty six completed questionnaires were returned, giving a response rate of 13.2%. The majority of the hunters were male, aged between 40 and 60 years, and from the United States of America and Europe. Hunters perceived the level of service quality delivery by hunting providers to be relatively high and were generally satisfied with their South African safaris. As a result, they were willing to return for another hunting experience and were very likely to speak positively about their experiences. By performing exploratory and confirmatory factor analyses, a three-factor (augmented services, core services and supporting services) service quality construct was identified and confirmed. Multiple regression analyses found that core services was the strongest predictor of overall satisfaction; overall satisfaction was significantly related to revisit intention; and revisit intention significantly predicted word-of-mouth intention. An empirical model was accordingly constructed to replace the original conceptual model. iii It is recommended that South African hunting safari providers should: {u10007A} use the suggested measuring instrument to monitor their performance of service quality delivery on a regular basis; {u10007A} train their employees to ensure that they are knowledgeable and well prepared for field guidance and to promote ethical hunting practices; {u10007A} ensure an abundance of game and a wilderness atmosphere in the hunting area; {u10007A} conduct focus group studies to further understand the factors that shape clients’ perceptions of the safari experience; and {u10007A} invest in developing long-term relationships with existing clients.
- Full Text:
- Date Issued: 2010
- Authors: Han, Xiliang
- Date: 2010
- Subjects: Hunting trophies -- South Africa , Big game hunting -- South Africa , Big game animals -- South Africa , Safaris -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9362 , http://hdl.handle.net/10948/1244 , Hunting trophies -- South Africa , Big game hunting -- South Africa , Big game animals -- South Africa , Safaris -- South Africa
- Description: The diversity of wildlife resources and the highly-developed trophy hunting and game ranching industry make South Africa a sought-after destination for travelling hunters. Significant economic, social and ecological benefits result from the annual visits of 16 000 hunters. These benefits, in turn, accelerate industry competition. To maintain or increase the clientele base, hunting providers should continue to manage and improve their clients’ safari experiences. This research investigated visiting hunters’ South African safari experiences by measuring their perceptions of service quality, satisfaction and behavioural intention. The results of the research could assist hunting providers in identifying areas where service expectations are not met and understanding the impact of service quality and satisfaction on clients’ loyalty. The literature study contextualised the South African trophy hunting industry within the tourism environment, the realms of wildlife tourism, and the characteristics of hunting tourism. An overview of tourism services, service quality, customer satisfaction, and behavioural intention was also provided. The resulting conceptual model hypothesised relationships among the safari experience variables (service quality, satisfaction and behavioural intention). ii The empirical data were collected by means of a mail survey, using a self-administered questionnaire distributed to 2 000 foreign hunters who had participated in a South African hunting safari at least once between 2003 and 2007. Two hundred and thirty six completed questionnaires were returned, giving a response rate of 13.2%. The majority of the hunters were male, aged between 40 and 60 years, and from the United States of America and Europe. Hunters perceived the level of service quality delivery by hunting providers to be relatively high and were generally satisfied with their South African safaris. As a result, they were willing to return for another hunting experience and were very likely to speak positively about their experiences. By performing exploratory and confirmatory factor analyses, a three-factor (augmented services, core services and supporting services) service quality construct was identified and confirmed. Multiple regression analyses found that core services was the strongest predictor of overall satisfaction; overall satisfaction was significantly related to revisit intention; and revisit intention significantly predicted word-of-mouth intention. An empirical model was accordingly constructed to replace the original conceptual model. iii It is recommended that South African hunting safari providers should: {u10007A} use the suggested measuring instrument to monitor their performance of service quality delivery on a regular basis; {u10007A} train their employees to ensure that they are knowledgeable and well prepared for field guidance and to promote ethical hunting practices; {u10007A} ensure an abundance of game and a wilderness atmosphere in the hunting area; {u10007A} conduct focus group studies to further understand the factors that shape clients’ perceptions of the safari experience; and {u10007A} invest in developing long-term relationships with existing clients.
- Full Text:
- Date Issued: 2010
Generating guidance on public preferences for the location of wind turbine farms in the Eastern Cape
- Authors: Hosking, Jessica Lee
- Date: 2012
- Subjects: Power resources -- South Africa -- Eastern Cape , Energy industries -- South Africa -- Eastern Cape , Wind power plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:8989 , http://hdl.handle.net/10948/d1009439 , Power resources -- South Africa -- Eastern Cape , Energy industries -- South Africa -- Eastern Cape , Wind power plants -- South Africa -- Eastern Cape
- Description: There is consensus that Eskom, South Africa’s main energy supplier, needs to expand its energy generating capacity in order to satisfy the growing demand for electricity, but there is less agreement on how it should do this. The existing supply is heavily reliant on thermal generation using coal, but the combustion of fossil fuels for electricity generation may contribute to climate change because it causes harmful greenhouse gases to be emitted into the atmosphere. This emission is something South Africa has committed itself to reducing. One way of achieving this is by the adoption of cleaner technologies for energy generation. One of these technologies is harnessing wind energy. The problem with harnessing wind energy is where to locate the turbines to harness the wind because these turbines ‘industrialise’ the environment in which they are located. They are a source of increased noise, a visual disturbance, cause increased instances of bird and bat mortality and the destruction of flora or the naturalness of the landscape in the areas in which they are located. The residents located near wind farm developments are most negatively affected and bear the greatest cost in this regard. A proper social appraisal of wind turbine projects would have to take this cost into account. Before such developments are approved there should be an assessment made of the impact on the residents, these impacts should be incorporated into the cost-benefit analysis. The negatively affected residents should also be compensated. The objective of this study was not to undertake a cost-benefit analysis of such a wind farm proposal, but to estimate the negative external cost imposed on nearby residents of such an industry, and thereby calculate appropriate compensation to be paid to these residents. Quantifying preferences for proposed, but not-yet developed, wind farms may be done by applying non-market valuation techniques, e.g. through one of the stated preference methodologies, such as a discrete choice experiment. The selected study site for providing guidance was one where Red Cap Investments Pty (Ltd) has proposed the development of a wind farm - in the Kouga local municipality. The basis for drawing conclusions was the analysis of the response samples of two groups of Kouga residents, distinguished by socio economic status; 270 from each group, 540 in total. The methodology applied to analyse the responses was a discrete choice experiment. The questionnaire administered included attitude, knowledge and demographic questions as well as a choice experiment section. The choice experiment section of the questionnaire required that the respondents choose between two different hypothetical onshore wind energy development scenarios and a status quo option. The hypothetical scenarios comprised different levels of wind farm attributes. The attributes included in the experiment were determined by international studies and focus group meetings. These attributes were: distance between the wind turbines and residential area, clustering of the turbines (job opportunities created by the wind farm development for underprivileged respondent group), number of turbines and subsidy allocated to each household. Three different choice experiment models were estimated for each socio-economic group: a conditional logit (CL), nested logit (NL) and a random parameters logit (RPL) model. It was found that, in the affluent respondent group, the simpler CL model provided the best fit. In the underprivileged respondent group, the RPL model, with the number of jobs created by the wind farm project as a random parameter1, explained by the gender of the respondent, provided the best fit. The estimated models identified distance as an important factor in both sampled respondent groups. Both respondent groups preferred that the wind farm be located further away from their residential areas. In addition to distance, the underprivileged respondent group also valued new job opportunities as an important determinant of choice. The affluent respondent group were very sensitive to densely clustered turbines but were almost indifferent between two of the effects coded levels of the clustering attribute “moderately close together” and “widely spaced apart”. Welfare estimates for the significant attributes in each socio-economic group were computed from the best fit models. Table 1 shows the resulting willingness to accept (WTA) compensation measures for distance in both socio-economic respondent groups.
- Full Text:
- Date Issued: 2012
Generating guidance on public preferences for the location of wind turbine farms in the Eastern Cape
- Authors: Hosking, Jessica Lee
- Date: 2012
- Subjects: Power resources -- South Africa -- Eastern Cape , Energy industries -- South Africa -- Eastern Cape , Wind power plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:8989 , http://hdl.handle.net/10948/d1009439 , Power resources -- South Africa -- Eastern Cape , Energy industries -- South Africa -- Eastern Cape , Wind power plants -- South Africa -- Eastern Cape
- Description: There is consensus that Eskom, South Africa’s main energy supplier, needs to expand its energy generating capacity in order to satisfy the growing demand for electricity, but there is less agreement on how it should do this. The existing supply is heavily reliant on thermal generation using coal, but the combustion of fossil fuels for electricity generation may contribute to climate change because it causes harmful greenhouse gases to be emitted into the atmosphere. This emission is something South Africa has committed itself to reducing. One way of achieving this is by the adoption of cleaner technologies for energy generation. One of these technologies is harnessing wind energy. The problem with harnessing wind energy is where to locate the turbines to harness the wind because these turbines ‘industrialise’ the environment in which they are located. They are a source of increased noise, a visual disturbance, cause increased instances of bird and bat mortality and the destruction of flora or the naturalness of the landscape in the areas in which they are located. The residents located near wind farm developments are most negatively affected and bear the greatest cost in this regard. A proper social appraisal of wind turbine projects would have to take this cost into account. Before such developments are approved there should be an assessment made of the impact on the residents, these impacts should be incorporated into the cost-benefit analysis. The negatively affected residents should also be compensated. The objective of this study was not to undertake a cost-benefit analysis of such a wind farm proposal, but to estimate the negative external cost imposed on nearby residents of such an industry, and thereby calculate appropriate compensation to be paid to these residents. Quantifying preferences for proposed, but not-yet developed, wind farms may be done by applying non-market valuation techniques, e.g. through one of the stated preference methodologies, such as a discrete choice experiment. The selected study site for providing guidance was one where Red Cap Investments Pty (Ltd) has proposed the development of a wind farm - in the Kouga local municipality. The basis for drawing conclusions was the analysis of the response samples of two groups of Kouga residents, distinguished by socio economic status; 270 from each group, 540 in total. The methodology applied to analyse the responses was a discrete choice experiment. The questionnaire administered included attitude, knowledge and demographic questions as well as a choice experiment section. The choice experiment section of the questionnaire required that the respondents choose between two different hypothetical onshore wind energy development scenarios and a status quo option. The hypothetical scenarios comprised different levels of wind farm attributes. The attributes included in the experiment were determined by international studies and focus group meetings. These attributes were: distance between the wind turbines and residential area, clustering of the turbines (job opportunities created by the wind farm development for underprivileged respondent group), number of turbines and subsidy allocated to each household. Three different choice experiment models were estimated for each socio-economic group: a conditional logit (CL), nested logit (NL) and a random parameters logit (RPL) model. It was found that, in the affluent respondent group, the simpler CL model provided the best fit. In the underprivileged respondent group, the RPL model, with the number of jobs created by the wind farm project as a random parameter1, explained by the gender of the respondent, provided the best fit. The estimated models identified distance as an important factor in both sampled respondent groups. Both respondent groups preferred that the wind farm be located further away from their residential areas. In addition to distance, the underprivileged respondent group also valued new job opportunities as an important determinant of choice. The affluent respondent group were very sensitive to densely clustered turbines but were almost indifferent between two of the effects coded levels of the clustering attribute “moderately close together” and “widely spaced apart”. Welfare estimates for the significant attributes in each socio-economic group were computed from the best fit models. Table 1 shows the resulting willingness to accept (WTA) compensation measures for distance in both socio-economic respondent groups.
- Full Text:
- Date Issued: 2012
- «
- ‹
- 1
- ›
- »