A framework for the implementation of e-government as a service delivery mechanism in South Africa: The case of the Eastern Cape Thusong Service Centres
- Authors: Madyibi, Ayanda
- Date: 2020
- Subjects: Electronic government information Technological innovations Information technology
- Language: English
- Type: Thesis , Doctoral , PhD(Information Systems)
- Identifier: http://hdl.handle.net/10353/18908 , vital:42997
- Description: E-government has emerged as an effective means of delivering much-needed online services to the citizens, businesses and other government institutions. This emanates from the advancement of Information and Communication Technology (ICT), the internet and the emerging technologies associated with the Fourth Industrial Revolution (4IR). E-government has essentially transformed the culture, structure and the way of doing business by public institutions in providing government services. In the past, e-government has been popular in developed countries but recently many developing countries are starting to appreciate the need to implement the initiative. However, the implementation of e-government has various challenges that have been identified through research and include technological, organisational and environmental aspects. Therefore, the researcher was motivated to study e-government to improve the delivery of services to citizens in South Africa. The objective of the research was to develop a framework for the implementation of egovernment as a service delivery mechanism in South Africa. The research process led to the identification of challenges that impact the implementation of e-government by applying an underlying Information Systems (IS) theoretical model, namely the Technology-OrganisationEnvironment (TOE) framework. The review of literature allowed the researcher to construct a conceptual theoretical framework which was then applied to the case study in order to understand the factors affecting the implementation of e-government in South Africa. Qualitative research data was collected using Thusong Service Centres in the Eastern Cape as a case study. Thusong Service Centres are government service centres based in rural communities which are used for the provision of online government services to these communities. The empirical data was collected using 22 respondents from five organisational and user perspectives: (1) State Information Technology Agency (SITA) as an agency of government responsible for ICT in South Africa, (2) the Senior ICT Managers from various National, Provincial and Local government entities, (3) Thusong Service Centre Managers, (4) Thusong Service Centre End-Users and (5) Expert Reviews. Documents that included the National e-Government Strategy, e-Government Policy, National Broadband Policy, ICT Policy White Paper were also consulted as secondary data. The conceptual theoretical framework was then revised based on the empirical evidence using the interpretive exploratory approach and triangulated data. The consolidated data from both the literature review and empirical evidence assisted in closing the gap between e-government implementation theory and practice. A detailed e-government implementation framework was then developed with the critical factors that impact the successful implementation of e- ii | P a g e government. E-government subject experts were also given the mandate to review the interview questions and the framework. The use of this framework was then explained in terms of how it can assist government decision-makers in South Africa for the effective and efficient delivery of services to the citizens. The research study has contributed to the e-government body of knowledge through the identified factors utilising the TOE framework at an organisational level for developing countries like South Africa.
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- Date Issued: 2020
A framework for the management of environmental information in Higher Education Institutions
- Authors: Jonamu, Blessing Tapiwa
- Date: 2014
- Subjects: Sustainability , Universities and colleges , Environmental management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10492 , http://hdl.handle.net/10948/d1020620
- Description: Higher Education Institutions (HEIs) are not immune to the global environment problems. An increasing awareness of the environmental responsibilities of HEIs has led researchers to investigate the role of environmental information and Environmental Management Information Systems (EMISs) in HEIs. EMISs play a major role in environmental management and environmental decision making in HEIs. Internationally, an increasing number of HEIs are embracing the concept of ‘sustainable HEIs’ by undertaking green campus initiatives. HEIs often use diverse information systems, some of which are manual systems, proven to be inefficient and this gives rise to redundant and inconsistent databases which result in non-compliance with regulations, confusion and lack of co-ordinated effort. There is therefore need for an integrated, comprehensive software system and framework which can assist with the efficient management of environmental information at South African HEIs. This study fills a gap in the field of environmental sustainability at HEIs as the evaluation of existing sustainability programs has shown common weakness such as: Failure to effectively set baselines, flaws in data acquisition and management and missing documentation. The aim of this study is to propose a framework for Environmental Information Management (EIM) in HEIs. The framework includes guidelines related to the components of the framework which can also be used to perform a gap analysis to facilitate the improved design of effective and efficient EIM processes and data stores. The Design Science Research (DSR) methodology is the research methodology used in the development of the two artifacts of this study namely: The EIM framework for HEIs and an EMIS prototype to serve as proof of concept. Problem identification and motivation was the first activity of the DSR which was done through a rigorous literature review and an investigation and evaluation of extant systems. This resulted in the design of an initial EIM framework for HEIs. Nelson Mandela Metropolitan University (NMMU) was the HEI used as the case study. The EIM framework was applied at NMMU and this enabled the researcher to understand the current As-Is EIM processes at NMMU and this resulted in clear objectives of a solution. The EMIS prototype (data warehouse) was then designed and implemented based on the theoretical framework. Three sets of evaluations were done to determine the acceptance of the EIM framework for HEIs and the performance of the EMIS prototype. The EIM framework was generally positively accepted and minor suggestions were made. An updated version of the EIM framework was proposed and evaluated. The experimental evaluation results showed that the EMIS prototype was efficient and effective. The contribution of this study is an EIM framework for HEIs and an implementation of an EMIS (EnviroDW) at NMMU that could be utilised by other HEIs.
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- Date Issued: 2014
A framework for transmitting and entrenching values in indigenous black South African family businesses
- Authors: Kupangwa, Welcome
- Date: 2021-12
- Subjects: Family-owned business enterprises -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/53991 , vital:46171
- Description: Family businesses are the predominant form of business globally and their importance to the economies of countries and job creation are often highlighted. In comparison to non-family businesses, family businesses are often described as having several unique characteristics such as a long-term orientation, being more emotions-laden, and having multiple family generations work in the business. Family businesses are also more deeply rooted in their cultures and values than non-family businesses are, and it is these values that contribute to their uniqueness and longevity. The dominant cultures and values found in family businesses are often associated with those of the founders and their families, and most founders want successive generations to run their family businesses according to established traditions and core values. Despite their importance in both developed and developing economies, family businesses face significant challenges to survive and prosper across generations. One such challenge involves the transmission of values from business founders and/or current leaders to the next generation of family members. If these values are not transmitted to and shared by the next generation, and not entrenched into the functions and processes of their family business, the functioning of the family and the family business are at risk. Existing research on values in family businesses reveals limited knowledge of values transmission to the next generation of family members. In addition, questions remain unanswered as to how values are institutionalised and entrenched into family businesses, and how these values contribute to their longevity and success. Given the need to understand the role of values in the transgenerational success of family businesses, many research calls have been made to investigate the nature of values, values transmission and values entrenchment among family businesses, including those in developing countries. In response to these calls the primary objective of this study was to provide a framework for explaining how values are transmitted among indigenous Black South African business owning families and how these values are entrenched into their family businesses. Investigating values in the context of indigenous Black South African business owning families highlights the influence of indigenous culture on the transmission and entrenchment processes. This study is positioned in the interpretivism and the postmodernism research paradigm. Both deductive and inductive reasoning to theory development and qualitative methodological approach were adopted to create new and richer understandings and interpretations of the phenomena under investigation. Utilising a multiple and descriptive case study methodology, data was collected from seven indigenous Black South African family businesses through semi-structured interviews. To corroborate the interview findings, observations, document analysis and field notes were also used for data collection, which was then analysed utilising reflexive thematic analysis. , Thesis (PhD) -- Faculty of Business and Economic Sciences, 2021
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- Date Issued: 2021-12
A framework of macroeconomic factors to be considered when evaluating commercial real estate development in sub-Saharan Africa
- Authors: Lawson, Stephen
- Date: 2019
- Subjects: Commercial real estate -- Development -- Sub-Saharan Africa , Real estate investment -- Sub-Saharan Africa Macroeconomics
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/40072 , vital:35745
- Description: Sub-Saharan Africa as a region is one with great potential given the positive demographic trends experienced in recent history, trends expected to continue into the future. The factors contributing to this positive demographic trend include, improved healthcare, education and life expectancy, all of which have contributed to a younger and growing population. The younger and growing population, the majority of which are located within the working age group, have resulted in high rates of urbanisation as the populous move from traditional rural areas to more urbanised areas and cities in search of greater opportunities, employment, and ultimately, better quality of life. The positive population growth and urbanisation trends exhibited in the region provide an opportunity to the role players in industry and commerce, as they seek to take advantage of the growing consumer base. Accordingly, commercial real estate developers active within the region have an opportunity to satisfy the growing needs of the market given the low levels of commercial real estate stock available in the region. However, historically the region has served as a poor investment destination for commercial real estate given the dynamic and occasionally volatile political, economic and legal environments. The opportunity presented to commercial real estate developers as a result of the positive demographic trends is met with large scale risks in the form of a dynamic and ever-changing macroeconomic environment within the region. To ensure the success, profitability and longevity of their commercial real estate developments, active real estate developers and in pursuit of commercial real estate development in sub-Saharan Africa need to approach the opportunities in a cautious and informed manner. The purpose of the study is to develop a framework which will identify a common set of macroeconomic factors and associated variables in order to assist South African real estate developers in the identification, mitigation and management of macroeconomic risks when evaluating commercial real estate in sub- Saharan Africa. A frame of reference was developed on the PESTEL Analysis in order to identify factors within the macroeconomic environment, following which a literature-driven framework was developed after an extensive literature review process, which identified macroeconomic risk variables associated with each of the factors identified. The literature-driven framework was then tested through a series of semi-structured interviews, which comprised five suitably qualified and experienced respondents who are real estate developers currently active in pursuit of commercial real estate development in sub-Saharan Africa and are currently employed by or own a real estate development organisation. Following the data analysis of the respondent interviews, a proposed framework was developed which detailed the macroeconomic factors and associated variables to be considered when evaluating commercial real estate development in sub-Saharan Africa, by providing a ranked scale of relevance for the variables associated with the respective macroeconomic risk factors identified. The development of the proposed framework is intended to assist South African real estate developers in the identification, mitigation and management of macroeconomic risks when evaluating the development of commercial real estate in sub-Saharan Africa.
- Full Text:
- Date Issued: 2019
A framework to enhance Information and Communication Technology (ICT) readiness for business continuity at the South African Revenue Services (SARS)
- Authors: Mathase, Euphodia
- Date: 2020
- Subjects: Internet in public administration -- Taxation -- South Africa Electronic commerce -- Government policy -- South Africa
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/49496 , vital:41726
- Description: Many organisations, especially public sector organisations, are required to ensure that they are able to continue with their operation in cases of major disasters that affect the organisations. In the same light, the South African Revenue Services (SARS), being a quasi-government organisation, faces a similar phenomenon. The main purpose of conducting this research was to explore a problem in depth that was identified at the SARS. SARS does not have a comprehensive business continuity plan. The study therefore examined possible techniques or actions for ensuring information and communication technology (ICT) readiness and business continuity, explored various frameworks and policy documents which will assist public entities with readiness for business continuity, and identified frameworks that will assist SARS in implementing an effective ICT readiness for business continuity. The study adopted the design science research approach and aspects of design science research in information systems. Data gathered through the questionnaire instrument was used to design a framework that can be adopted at SARS to enhance ICT readiness for business continuity. The research findings show the importance of effective business continuity management (BCM) and a framework that can be used to implement an effective BCM.
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- Date Issued: 2020
A framework to enhance the mobile user experience in an Mlearning interaction
- Authors: Botha, Adele
- Date: 2011
- Subjects: Educational technology , Information technology , Educational innovations , Teaching -- Aids and devices
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9753 , http://hdl.handle.net/10948/d1008163 , Educational technology , Information technology , Educational innovations , Teaching -- Aids and devices
- Description: The new millennium is witness to a telecommunications world that is vastly different from even the recent past with developments in the mobile sector having dramatically changed the Information and Communication Technology (ICT) landscape. Mobile cellular technology has proliferated faster than any previous technology and is now the most ubiquitous technology in the world. The focus of this thesis is the development of a framework to enhance the Mobile User Experience in an Mlearning interaction. This research is contextualised by the goal-oriented use of mobile cellular technologies in a formal educational environment. As such the study, although residing in the field of Human-Computer Interaction (HCI), acknowledges issues arising in the Education Domain as a specific field of application. The aim of the research was to investigate the components of a framework to enhance the Mobile User Experience in an Mlearning interaction. The development of the framework was facilitated by the exploration of: the Mobile User Experience factors and their impact, on the Mobile User Experience of learners participating in a goal-oriented Mlearning interaction. These critical factors were documented in terms of the Mobile User Experience components, and the relationships of these components to each other as well as the Mobile User Experience of an Mlearning interaction. The research, grounded in a phenomenological research philosophy, applied an inductive reasoning approach, and was operationalised through a single case study methodology. A qualitative research strategy was considered appropriate, as the phenomenon of User Experience is linked to the hedonistic attributes of the interaction. This study was conducted in four phases with focus on three embedded units of analysis. The three units of analysis were identified as: The learner as end user in an Mlearning interaction; The educator as designer of the Mlearning interaction; and The Mlearning interaction. The research revealed that the Mobile User Experience of an Mlearning interaction is affected by the mobile user, mobile use, mobile device, mobile business practices, mobile networks, mobile interaction and mobile context. Within the Mlearning interaction the significant components are the learners as mobile users, the enhance interactions, removal of barriers to the interaction, goal-oriented nature of the interaction and the ducational context. Identifying these components and their associated Mobile User Experience factors and impacts, present the main contribution of this thesis. In conclusion, the limitations of the study are documented and topics for future research are outlined.
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- Date Issued: 2011
A framework to influence the behavioural intention of adults to monitor their health using gamification: a case of discovery vitality in East London, South Africa.
- Authors: Ntshona, Linda
- Date: 2021-09
- Subjects: Autonomy (Psychology) , Medical telematics. , Patient self-monitoring.
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22242 , vital:52005
- Description: The epidemic of overweight or obesity conditions has become a public health concern in South Africa, and signifies major challenges of chronic diseases affecting the healthcare sector. Recent years have noted the increasing prevalence of gamification and development across all age groups. The rapid adoption and use of gamification as a tool to improve adult motivation and engagement when monitoring their health and wellness is an essential form of health intervention. Gamification allows its users to keep track of their health in real time and encourages an active healthy lifestyle behaviour. Research has found that there are factors that may inhibit the behavioural intention of adults to use gamification for health monitoring in the long term. These factors include cost or membership fees associated with gamification that uses Discovery Vitality and privacy concerns. The main aim of this research study was to develop a framework to influence the behavioural intention of adults to monitor their health through gamification making use of Discovery Vitality as the case study. The self-determination theory was used as the theoretical framework to ensure continuance usage of gamification for sustained health monitoring. A qualitative research approach was chosen for this study. The purposive sampling technique was selected to identify 20 adults between the ages of 18-59 years that are members of Discovery Vitality in East London, South Africa. Interviews were conducted with the 20 participants to identify the factors that will influence their behavioural intention to make use of gamification to monitor their health. After data collection, thematic analysis was used to analyse the data and the data provided by the participants was organised and summarised into relevant themes to answer the main research question. The study developed a framework which incorporated the four constructs of the self-determination theory, namely perceived autonomy, competence, relatedness and satisfaction of basic psychological needs for sustained health monitoring. The study also developed the five factors influencing the behavioural intention of adults to continue using gamification for sustained health monitoring. These factors are known as: broad appeal, applicability and accessibility through mobile technology and pervasive sensors, development and accomplishment, employment of creativity and feedback, and lastly social influence and relatedness. The recognition of weight loss, tracking and monitoring of physical activities and medication adherence was found to positively influence the behavioural intention of adults to continuosly use gamification to monitor their health. , Thesis (MCom) (Information Systems) -- University of Fort Hare, 2021
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- Date Issued: 2021-09
A gatherer’s paradise? early humans and plant foraging on the Cape south coast, South Africa
- Authors: Botha, Maria Susan
- Date: 2019
- Subjects: Plant remains (Archaeology) -- South Africa , Plant physiology Plant ecology Botany -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/37139 , vital:34124
- Description: Humans were driven to refugia during the cold and dry glacial Marine Isotope Stage 6 (MIS6) (~195–125 ka); only a few places, including the Cape south coast, show archaeological evidence of continuous human occupation. It has been hypothesised that the Cape south coast provided the requisite shelter to ensure human’s earliest survival because it provided all the right ingredients. The shores offer abundant shellfish, the land a diverse array of plants, and the climate was ameliorated due to the proximity of the then exposed Palaeo-Agulhas Plain to the warm Agulhas current. The aim of this study is to determine whether the indigenous flora of this region could have provided a sufficient edible resource for early humans. Residents of the Cape south coast have genetic ancestry linking them to the Khoe-San, the original inhabitants of the area, and still have an extensive knowledge of the local edible plants. With their help, I set out to determine a) whether humans have been utilising the same plant species over time, b) what the foraging potential of the edible plants in the region is and c) how resilient these plants are to human foraging. If we know whether the plant species known and used today were the same as those that were utilised by past humans, we can then use the contemporary knowledge to make predictions about past utilisation. To answer this question, I collated two databases: archaeological (all plant species found in archaeological sites [dating 0 to 80,000 BP]) and contemporary (all plant species in the modern-day ethnographic literature [last 400 years]) that occur within the Greater Cape Floristic Region(GCFR). I found a significant number of plant species shared between the two databases, which suggests that at least some plant species have been used by humans over a long period of time. To determine the indigenous plant foraging potential of the region, I foraged for food in the Cape south coast (451 bouts) monthly over a two-year period with the help of local inhabitants. The findings show that edible plant resources are distributed patchily and focusing on specific vegetation types would greatly enhance chances of harvesting 2,000 kcal per day, which is considered the daily calorific requirements for a typical hunter-gatherer. I then sought to understand how resilient these plants [(with an emphasis on plants with an underground storage organ (USO)] would be to human foraging. To do this, I set out plots and harvested all edible foods for three consecutive years with the help of foragers. Results indicate that there was a significant reduction in edible weight only in the third year of consecutive harvesting. In conclusion, using various approaches, this study investigates the plant food potential of the Cape south coast from the perspective of early human consumers. The findings suggest that knowledge regarding useful plants dates back to at least 80,000 BP. Food resources are patchily distributed across the main vegetation types found within the Cape south coast and occur in hotspots, i.e. concentrated areas hosting high densities of edible plant foods, surrounded by areas with very low plant food densities. Foragers could have harvested their daily calorific quota more easily if they focused their harvesting efforts in specific vegetation types found in the Cape south coast. Furthermore, many USOs circumvent climatic fluctuations, herbivory or both by staggering their emergence over multiple years, which implies they have some resilience to human foraging.
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- Date Issued: 2019
A genetic analysis of the species and intraspecific lineages of Dactylopius Costa (Hemiptera: Dactylopiidae)
- Authors: Van Steenderen, Clarke
- Date: 2020
- Subjects: Dactylopius
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/151491 , vital:39135
- Description: The Cactaceae family comprises 15 genera and nearly 2000 species. With one exception, these are all native to the Americas. Numerous cactaceous species are invasive in other parts of the world, resulting in considerable damage to ecosystem functioning and agricultural practices. The most successful biological control agents used to combat invasive Cactaceae belong to the Dactylopius genus (Hemiptera: Dactylopiidae), comprising eleven species. The Dactylopiidae are exclusively cactophagous and are usually host-specific. Some intraspecific lineages of dactylopiids, often referred to as `biotypes', also display host-specificity, and are used to control particular species of invasive Cactaceae. To date, two lineages within Dactylopius opuntiae (`ficus' and `stricta'), and two within D. tomentosus (`cholla' and `imbricata') have been released in South Africa to control Opuntia ficus-indica and O. stricta, and Cylindropuntia fulgida and C. imbricata, respectively. The `californica var. parkeri' lineage is currently under consideration for release in South Africa for the control of C. pallida. Australia has already released these five lineages, and approved the release of an additional three in 2017; namely D. tomentosus `bigelovii', `cylindropuntia sp.', and `acanthocarpa x echinocarpa'. Many of the Dactylopius species are so morphologically similar, and in the case of lineages, identical, that numerous misidentifications have been made in the past. These errors have had serious implications, such as failed attempts at the biological control of cactus weeds. This thesis aimed to generate a multi-locus genetic database to enable the identification of the species and lineages in the Dactylopiidae family, and to test its accuracy. Seven species were included in the analysis, including two lineages within D. opuntiae and six within D. tomentosus. Genetic characterisation was achieved through the DNA sequencing of three gene regions; namely mitochondrial 12S rRNA and cytochrome c oxidase I (COI), nuclear 18S rRNA, and fragment analysis using two inter-simple sequence repeats (ISSRs). Nucleotide sequences were very effective for species-level identification, where the 12S, 18S, and COI regions showed 100%, 94.59%, and 100% identification accuracy rates, respectively. Additionally, the 12S and COI markers distinguished between half of the D. tomentosus lineages (`californica', `cholla', and `imbricata'), with identification accuracies of 100%. The `echinocarpa x acanthocarpa', `bigelovii', and `cylindropuntia sp.' lineages formed one clade. None of the DNA genetic markers showed a separation between the `ficus' and `stricta' lineages within D. opuntiae. Fragment analysis through the use of ISSRs provided higher-resolution results, and addressed this gap by showing a well-supported separation between the two lineages, and between wild populations collected in the Eastern Cape Province in South Africa. The identification accuracy of the `ficus' and `stricta' lineages was 81.82%. This is the first time that a method has been developed that can distinguish between these lineages. An additional component of this thesis was the creation of three user-friendly R-based programs to assist with: 1. ISSR data processing. 2. The identification of query Dactylopius nucleotide sequences relative to the gene databases created here. 3. A graphical user interface (GUI) version of the R package `SPIDER', which is useful for the assessment of the accuracy of genetic barcode data. A successful biological control programme relies on the correct identification of the agent in question, and so it is imperative that cactus biological control practitioners are able to distinguish between Dactylopius species and lineages in order to release the most effective ones onto target Cactaceae. The laboratory protocols reported, and data processing tools created here, have largely addressed this need and offer valuable practical applications. These include: 1. The flagging of potential new species, cryptic species, and lineages of dactylopiid species released as new biocontrol agents. 2. Validating the identifications made by taxonomists based on morphology. 3. Confirming to which species, and, where applicable, to which lineage, a field-collected sample belongs. 4. Identifying hybrids resulting from lineage crosses. Ensuring that the correct Dactylopius species are utilised for biological control will improve the control of invasive Cactaceae and protect biodiversity and agricultural productivity.
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- Date Issued: 2020
A genetic and ecophysiological comparison of co-occuring indigenous (Perna perna) and invasive (Mytilus galloprovincialis) intertidal mussels
- Authors: Zardi, G I
- Date: 2006
- Subjects: Perna -- South Africa Mytilus galloprovincialis -- South Africa Mussels -- South Africa Mytilidae -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5613 , http://hdl.handle.net/10962/d1003066
- Description: The Mediterranean mussel Mytilus galloprovincialis is the most successful marine invasive species in South Africa. Its presence has had significant ecological consequences on the intertidal communities of the west coast. On the south coast, M galloprovincialis co-exists and competes with the indigenous intertidal mussel Perna perna in the lower balanoid zone, where they show partial habitat segregation. The upper and the lower mussel zones are dominated by M. galloprovincialis and P. perna respectively while they co-occur in the mid zone. In this thesis M. galloprovincialis and P. perna are compared in terms of their population genetics and their ecophysiology. The success of an invader depends on its ability to react to new environmental factors, especially when compared to indigenous species. The distribution and diversity of intertidal species throughout the world are strongly influenced by periodic sand inundation and hydrodynamic stress. Occupying the lower intertidal zone, P. perna is more strongly influenced by sand (burial and sand in suspension) than M. galioprovincialis. Despite this, P. perna is more vulnerable to the effects of sand, showing higher mortality rates under experimental conditions in both the laboratory and the field. M. galioprovincialis has longer labial palps than P. perna, indicating a better ability to sort particles. This, and a higher tolerance to anoxia, explains its lower mortality rates when exposed to burial or suspended sand. Habitat segregation is often explained by physiological tolerances, but in this case, such explanations fail. The ability of a mussel to withstand wave-generated hydrodynamic stress depends mainly on its byssal attachment strength. The higher attachment strength of P. perna compared to M. galioprovincialis and of solitary mussels compared to mussels living within a bed (bed mussels) can be explained by more and thicker byssal threads. M galloprovincialis also has a wider shell, is subjected to higher hydrodynamic loads than P. perna and shows a higher theoretical probability of dislodgement, this is borne out under field conditions. The attachment strength of both species increased from higher to lower shore, in parallel to a gradient of a stronger wave action. Monthly measurements showed that P. perna is always more strongly attached than M. galloprovincialis and revealed seasonal fluctuations of attachment strength for both species in response to wave height. The gonad index of both species was negatively cross-correlated with attachment strength. The results are discussed in the context of the evolutionary strategy of the alien mussel, which directs most of its energy to fast growth and high reproductive output, apparently at the cost of reduced attachment strength. This raises the prediction that its invasive impact will be more pronounced at sites subjected to low or moderate wave action at heavily exposed sites. The potential of a species for invasion is also determined by the ability of the invader to disperse. Population genetics provide indirect information about dispersal through a direct measurement of gene flow. The low genetic divergence (measured as mtDNA) of M. galloprovincialis confirms its recent arrival in South Africa. In contrast, the population genetics structure of P. perna revealed strong divergence on the south-east coast, resulting in a western lineage (straddling the distributional gap of the Benguela System), and an eastern lineage, with an overlap region of the two on the south coast between Kenton-on-Sea and Haga Haga. This genetic disjunction may be caused by Agulhas Current acting as an oceanographic barrier to larval dispersal, or by different environmental selective forces acting on regional populations. Over the last ten years, M. galloprovincialis has shown a decrease or cessation of its spread to the east in exactly the region of the genetic disjunction in P. perna, again suggesting either an oceanographic barrier to larval dispersal, or increasing selection driven by sharp gradients in environmental conditions.
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- Date Issued: 2006
A Geochemical Comparison of Southern African Stromatolites and Stromatolite Pools
- Authors: Dodd, Carla
- Date: 2020
- Subjects: Stromatolites
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48235 , vital:40527
- Description: Microbialite accretion takes place via either mineral precipitation, the trapping and binding of mineral and sediment grains, or a combination of the two. Recently, the geochemistry of carbonate deposits, including microbialites, has been used to reconstruct palaeoenvironments and infer biogenicity. Numerous modern stromatolite (layered microbialites) systems are located on the southern African coastline and are formed predominantly by mineral precipitation with minor detrital input. In order to better understand the environmental and biological processes influencing the formation of microbialites, the geochemistry of southern African coastalstromatolites is examined. This is done by a spatial comparison of the hydrochemistry as well as the major and trace element geochemistry of various coastal stromatolite systems. The influence of the underlying geology on the composition of the stromatolites forms a particular focus of the study. In addition, the effect of metazoans on the micro-fabrics and sediment incorporation into the stromatolite matrix is assessed. Finally, the trace element geochemistry of active, inactive, and ancient stromatolites is compared with a speleothem sample in order to test the validity of using trace elements as a means to determine biogenicity of deposition. Results show that the bulk geochemistry of the South African stromatolites is not a simple function of the associated bedrock lithologies, although certain parallels do exist. It was found that metazoans indirectly influence sediment incorporation by increasing porosity and thereby accommodation space for detrital input. Furthermore, trace element signatures could not be directly attributed to microbial influence in the deposition of the carbonates. Ultimately, this study provides valuable insights into the formation processes of the active South African stromatolites and the use of trace elements as a geochemical tool to investigate the evolution of life and determine past environmental conditions.
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- Date Issued: 2020
A geological evaluation of marine diamond placer deposits on the central Namibian inner shelf : a case study of the Hottentot Bay area
- Authors: Rau, Grant
- Date: 2004 , 2013-06-03
- Subjects: Diamond mines and mining -- Namibia , Ocean mining -- Namibia , Marine mineral resources
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5038 , http://hdl.handle.net/10962/d1007554 , Diamond mines and mining -- Namibia , Ocean mining -- Namibia , Marine mineral resources
- Description: This study focusses on the marine diamond placers within Exclusive Prospecting Licence 1950 and Mining Licence 103a, located northwest of the north-facing Hottentot Bay which is 60 km north of Lüderitz, along the central Namibian coastline. The thesis follows the natural geological evolution of the marine placer deposit from primary source, through alluvial and/or glacial transportation, concentration along the coastline by wave, aeolian and alluvial/sheet-wash processes and finally marine diamond placer preservation. All of these processes are reviewed as they are important in understanding of the evolution marine placer deposits. The poly-cyclic role of coastal aeolian, alluvial, and marine processes, in marine placer enrichment is shown to be particularly important in considered target identification and prioritisation. A detailed bathymetric, sonographic and seismic interpretation, is an integral part of diamond placer exploration, and was used to examine and describe surficial and sub-bottom characteristics within the study area. Marine placers are formed along palaeo-strandlines during periods of marine transgression and regression and are therefore fundamental in marine placer exploration. A detailed bathymetry map, compiled for this study, of the area between Lüderitz Bay and Clara Hill, provides the foundation for a detailed terrace level investigation. Regionally, twelve well-developed stillstand levels are identified, nine of which fall into the study area. These interpretations are compared with global eustatic as well as terrace and resource/reserve levels in the Lüderitz area and are found to correlate well. Sediment dynamic studies involve the use of accredited application software for wave refraction modelling, to determine the wave angle and orbital wave velocity at the seabed. Bedload velocities, required to move diamonds of specific sizes, can be empirically determined and therefore areas of diamond entrainment and deposition can be modelled and target features delineated and prioritised. These detailed interpretations provide a sound platform for evaluating diamond placer process models in the study area. By integrating both previously published and newly formulated ideas, a revised, holistic model for the formation of marine diamond placer deposits in central Namibian is postulated. The proposed model is tested by comparing it to the lateral distribution of presently defined resource/reserve areas in the Lüderitz area and shows a close correlation with most of these enriched deposits. Based on this model, a matrix for the delineation and prioritisation of marine placer deposits is developed and the best target features within the study area are identified. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2004
A goal-setting intervention with motocross racers : a case study investigating the effects of an intervention on perceived motivation, confidence, and self-efficacy
- Authors: Fleming, Tracey Laura
- Date: 2014
- Subjects: Motocross -- Psychological aspects -- Research , Motorcyclists -- Psychological aspects -- Research , Goal (Psychology) -- Research , Competition (Psychology) -- Research , Motivation (Psychology) -- Case studies , Confidence -- Case studies , Self-efficacy -- Case studies , Sports -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3224 , http://hdl.handle.net/10962/d1012996
- Description: This study aimed to investigate the effects that a specifically tailored goal-setting program would have on two motocross racers in terms of their self-efficacy and motivation, as well as the process of designing this intervention. This case-study approach involved a mixed methods approach, consisting of pre-intervention and post-intervention assessments, interviews, and performance profiles. The tools used include Vealey’s (1986) Competitive Orientation Inventory (COI), Gill and Deeter’s (1988) Sport Orientation Questionnaire (SOQ), performance profiles, and semi-structured interviews. The goal-setting intervention lasted a total of five weeks. The results from the preintervention and post-intervention assessments were compared to determine whether any changes in motivation or self-efficacy occurred during the intervention. For the first participant, significant changes in both motivation and self-efficacy were present in addition to significant changes in competitive orientation. For the second participant, there were no significant changes in either motivation or self-efficacy. However, for the second participant there was also no change in competitive orientation. Findings suggest that the focus and competitive orientation of an athlete have a significant influence on the types of goals set, and consequently on positive changes in motivation, confidence, and self-efficacy. The influence of the competitive orientation in athletes also highlighted the importance of attaining a balance between performance and outcome goal-related activities. It was also discovered through qualitative assessment that this program is suitable for particular groups of athletes such as those who are injured, display an external locus of causality or are otherwise not performing at their prime.
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- Date Issued: 2014
A hermeneutical study of the Midrashic influences of biblical literature on the narrative modes, aesthetics, and ethical concerns in the novels of George Eliot
- Authors: Law-Viljoen, Bronwyn
- Date: 1993
- Subjects: Eliot, George, 1819-1880 -- Criticism and interpretation Eliot, George, 1819-1880 -- Language Eliot, George, 1819-1880 - Style Eliot, George, 1819-1880. Daniel Deronda Eliot, George, 1819-1880. Felix Holt Eliot, George, 1819-1880. Adam Bede Eliot, George, 1819-1880. Mill on the Floss Midrash -- History and criticism Midrash -- Hermeneutics Prophecy in literature Judaism in literature Jews in literature Symbolism in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2236 , http://hdl.handle.net/10962/d1002279
- Description: The thesis will examine the influence of Biblical literature on some of the novels of George Eliot. In doing so it will consider the following aspects of Eliot criticism: current theoretical debate about the use of midrash; modes of discourse and narrative style; prophetic language and vision; the influence of Judaism and Jewish exegetical methods on Adam Bede, "The Lifted Veil", The Mill on the Floss, Felix Holt, and Daniel Deronda. Literary critics have, for a long time, been interested in the influence of the Bible and Biblical hermeneutics on literature and the extent to which Biblical narratives and themes are used typologically and allegorically in fiction has been well researched. In this regard, the concept of midrash is not a new one in literary theory. It refers both to a genre of writing and to an ancient Rabbinic method of exegesis. It has, however, been given new meaning by literary critics and theoriticians such as Frank Kermode, Harold Bloom, and Jacques Derrida. In The Genesis of Secrecy, Kermode gives a new nuance to the word and demonstrates how it may be used to read not only Biblical stories but secular literature as well. It is an innovative, self-reflexive, and intricate hermeneutic processs which has been used by scholars such as Geoffrey Hartman and Sanford Budick, editors of Midrash and Literature, a seminal work in this thesis. Eliot's interest in Judaism and her fascination with religion, religious writing, and religious characters are closely connected to her understanding of the novelist's role as an interpreter of stories. In this regard, the prophetic figure as poet, seer, and interpreter of the past, present, and future of society is of special significance. The thesis will investigate Eliot's reinterpretation of this important Biblical type as well as her retelling of Biblical stories. It will attempt to establish the extent to which Eliot's work may be called midrash, and enter the current debate on how and why literary works have been and can be interpreted. It will address the questions of why Eliot, who abjures normative religious faith, has such a profound interest in the Bible, how the Bible serves her creative purposes, why she is interested in Judaism, and to what extent the latter informs and permeates her novels.
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- Date Issued: 1993
A historic-hermeneutic critique of luthiery with specific reference to selected South African guiter builders
- Authors: Bower, Rudi
- Date: 2008
- Subjects: Guitar -- Construction , Guitar -- History
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8512 , http://hdl.handle.net/10948/779 , Guitar -- Construction , Guitar -- History
- Description: This study uses a general historical overview of luthiery that provides the reader with a basic understanding of construction techniques and terminology as a point of departure. From the outset the lack of consensus over an ideal or desired construction technique is highlighted. However, Torres is credited with the establishing of a perceived Spanish tradition of guitar construction and acknowledged as the “father” of the modern guitar. This will serve as a basic framework in which a discussion of six prominent past and present international luthiers can occur. These luthiers, namely Antonio de Torres, Hermann Hauser, Robert Bouchet, Daniel Friederich, Jose Romanillos and Greg Smallman are included in this study by virtue of their influence on the South African luthiers that are featured here. It is noted that these six luthiers, with the exception of Greg Smallman, all adhere to the “Spanish tradition” of guitar construction. Smallman can be considered a foremost proponent of a more recent “modern” school of guitar construction characterized by various innovative construction techniques. These are a result of new demands placed on the guitar as performance instrument because of larger concert venues and more collaboration with different instruments, resulting in a need for a stronger tone and more projection and penetration in sound. These two “poles” of luthiery are then manifested in the discussion on the seven featured South African luthiers. Alistair Thompson, Colin Cleveland, Mervyn Davis, Garth Pickard, Marc Maingard, Rodney Stedall and Hans van den Berg are discussed with special mention made of the features of their instruments, woods used and thoughts on luthiery, against the backdrop of their biographies. The four South African luthiers who build within the “Spanish tradition” (Pickard, Maingard, Stedall and Van den Berg) are distinguished from the three who build outside this so-called tradition (Thompson, Cleveland, Davis). South African luthiery is therefore shown to be an accurate microcosm of luthiery in global terms with styles of construction ranging from very “traditional” to very “modern”. The critical reflection on the information contained in this study appears in the form of a hermeneutic critique on luthiery that occurs within the parameters of the thought of two prominent hermeneutic thinkers, Martin Heidegger and his student, Hans-Georg Gadamer. It is shown that the collaboration that often occurs between guitar makers and performers can be related back to Gadamer and his analysis of Heidegger’s notion of the the hermeneutic circle. It is also argued that luthiery as practiced by the international and South African luthiers featured in this study can be seen both as art and technology in ancient Greek terms in that they are both a mode of revealing. Finally, it is shown how luthiery in its entirety can be viewed as a tradition and that different luthiers respond and add to this tradition in various ways.
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- Date Issued: 2008
A historical sociolinguistic study on the conceptualisation and application of justice and law kwisizwe samaXhosa as documented in and extracted From SEK Mqhayi And W.W. Gqoba’s selected writings
- Authors: Ntshingana, Sanele
- Date: 2019
- Subjects: Gqoba, William Wellington , Mqhayi, S. E. K. , Xhosa literature -- History and criticism , Law in literature , Justice in literature
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/115339 , vital:34115
- Description: This study seeks to investigate the original meanings contained in lexical terms relating to law (umthetho) and justice (ubulungisa) and their application in the precolonial Xhosa social society as they make appearance in SEK Mqhayi’s novel Ityala lamawele (1914) and WW Gqoba’s Isizwe esinembali, (1873-188/2015). Both of these works were written and initially published at the early point of contact of amaXhosa with the art of writing, and so are set in a ‘traditional’ setting (in the case of Mqhayi) and at early contact with European societies in Eastern Nguni region. This academic endeavour is undertaken by employing critical discourse theoretical framework. The purpose is to investigate the conceptualisation of law and justice amongst amaXhosa, and the extent to which this conceptualisation reflects the philosophical worldview of amaXhosa, as embedded in their language. The paper makes inferences about conceptualisation of law and justice in precolonial Xhosa social settings, and offers proposals on what this conceptual understanding could mean if its potential contribution to the contemporary understanding and application of law and justice in South Africa could be tapped into. The motivation for this study emanates from the current intellectual contestations in higher education that today’s curricula present western knowledge systems as universal while marginalising indigenous epistemologies in teaching, learning and research practices. At the centre of these debates is how research, social and scientific thinking in humanities, is profoundly shaped by imported, racist, western “canonical” texts and theories. The arguments presented by various scholars argue that this enterprise firmly roots the collective imagination of students about the past and present in racist Eurocentric schematic frames, thus creating a problem of identity loss, and an intentional distortion of historical truths. The space for knowledge systems and experiences reflecting African memory and imagination is not only neglected, but distorted too. In this context, the study seeks to delve deeper into how African languages can be used to reconstruct knowledge systems that reflect African ways of understanding society as part of creating a curriculum that depicts “multiversal” ways of knowing (Tisani 2000; Santos, 2014). This study makes several findings, chief amongst which is that the legal and justice systems of the precolonial Xhosa society was both corrective as opposed to today’s punitive court system that South Africa inherited, largely from the West. It seeks to prove that AmaXhosa’s precolonial legal and justice system was focused more on reintegrating the offender back into society. The study further will show how the precolonial amaXhosa justice system was embedded in the concepts of ubulungisa (correct and re-intergrate) and isohlwayo (that which brings one to basics). Through discourse analysis of the early literary isiXhosa texts, the thesis discovers that the application of ubulungisa amongst amaXhosa back then was consistent with the philosophies embedded in the concepts. By exposing the collaboration networks between the white missionaries and the colonial administrators of the nineteenth century, the thesis will show how conspiracies were directed at erasing and displacing these indigenous epistemologies and to replacing them with colonial memories. To this end, missionary accounts, explorer diary entries and reports and early lexicographic material were produced and archived. Furthermore, this study makes a proposition that early written Xhosa texts be entrenched in the today’s curricula in order inform the process of making sense of the social experiences and knowledge systems of the indigenous people of South Africa, from the precolonial-past to the present. Throughout the study, the thesis presents a proposition these early Xhosa texts be studied in relation to their intellectual contributions. This, it is hoped, will boldly challenge the canonised knowledge and racist assumptions about the African knowledge systems and experiences.
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- Date Issued: 2019
A historico-theological study of Pentecostalism as a phenomenon within a South African community
- Authors: Pillay, Gerald J
- Date: 1985
- Subjects: Pentecostalism -- South Africa Pentecostal churches -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1222 , http://hdl.handle.net/10962/d1001552
- Description: Preface: An attempt is made in this thesis to document the history of Pentecostalism among Indians in South Africa and to study and evaluate its religious character and main theological tenets. Obviously the peculiar socio-political situation of the Indians in South Africa has influenced the character of Indian Pentecostalism, which has in turn been able to address itself to the critical, cultural and religious disjunctions within this community. Hence an investigation of the dynamic tensions that obtain between crises in the Indian community and Pentecostalism will not only clarify the course of its history but will also explain its theological emphases. However, several studies on Pentecostalism in other communities have concentrated on the sociological dimension almost exclusively and many have even concluded that Pentecostalism is the spontaneous result of psychosocial; economic or cultural upheavals . This kind of reductionism has been largely the result of the uncritical use of 'functional-type' theories postulated by sociologists of religion. Indian Pentecostalism, while it has to be examined within the complex context of the South African community, cannot as we shall show, be adequately explained by any of the prevailing 'functional-type' theories because these theories reduce religion to a sociological function. Since the functional theory has the effect of limiting the perspective on religion to such an extent that the basis of religion, that is, the relation between the individual and faith, is either belittled or ignored, it has been jettisoned in this thesis for an approach free of any deliberately formulated 'theoretical framework'. However, it is necessary to critically examine some of the more popular 'functional-type' theories and the way they have been applied to the study of the Pentecostal movement here and elsewhere, so that by exposing the shortcomings of their application and the contradictions inherent in their assumptions, the approach adopted in this thesis could be clarified.
- Full Text:
- Date Issued: 1985
A history of the direct taxation of the African people of Kenya, 1895-1973
- Authors: Tarus, Isaac Kipsang
- Date: 2005
- Subjects: Mau Mau -- History Taxation -- Kenya Tax collection -- Kenya Fiscal policy -- Kenya Kenya -- Economic policy Kenya -- History -- 1895-1963
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2561 , http://hdl.handle.net/10962/d1002414
- Description: This study examines the origin, the manifestation and impact of the direct taxation of Africans in Kenya. While the state had several reasons for imposing taxation on Africans, the basic factor weighed on the need for a definitive source of revenue. For most of the colonial period, this aggregated to about 37½ percent of the total revenues. The thesis shows how taxes were collected from Africans, how this led to participation in the cash economy and how they continually resisted and evaded such taxation. Tax collection was synonymous with colonialism and this was manifested through the central role of chiefs, who used taxes and force to coerce Africans into migrant wage labour. Through taxation policies, legislation and African resourcefulness, migrant wage labour served the needs of a colonial capitalist settler economy. In this way, the colonial state revealed its capacity for dominance, power and exploitation. Evidence has been adduced to show that African taxation was an important factor in Kenya’s administrative, political and economic development. The policy of African taxation, land loss and poor working conditions are remembered as having interfered with African mechanisms for accumulating wealth. One of the main objections of the payment of taxes was the manner of its collection. Those unable to pay were imprisoned or detained while many took to instant flight at the sight of the tax collector. The thesis shows that in spite of all these harsh tax collection methods, peasants remained largely resilient and industrious. The Mau Mau movement was the culmination of various peasant grievances in which the colonial state used steep taxation as a counter-insurgency measure. Kenya’s independence in 1963, however, never altered the predatory nature of the state. Subtle, opportunistic and overt ways continued to be used to extract taxes from the peasants and the working class. It was not until 1973 that the much-hated colonial poll tax that had been renamed as graduated poll tax was abolished and replaced by indirect taxation. Finally, taxation like other colonial legacies has endured and has become one of the most important sources of revenue for the government to manage its fiscal policies.
- Full Text:
- Date Issued: 2005
A history of the Xhosa, c1700-1835
- Authors: Peires, J B (Jeffrey B)
- Date: 1977
- Subjects: Xhosa (African people) -- History
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2611 , http://hdl.handle.net/10962/d1013024
- Description: The boundaries of the territory occupied by the Xhosa fluctuated considerably, but in the period 1700-1835 they did not often extend west of the Sundays River, or east of the Mbashe River, along the coastal strip which separates the escarpment of South Africa's inland plateau from the Indian Ocean. It is an area of temperate grassland, permitting the cultivation of cereals and light crops, such as maize, millet, tobacco and pumpkins but better suited to stock-farming than intensive agriculture.
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- Date Issued: 1977
A hybrid approach to beach erosion mitigation and amenity enhancement, St Francis Bay, South Africa
- Authors: Anderson, Dylan Rory
- Date: 2008
- Subjects: Beach erosion -- South Africa -- St Francis Bay , Shore protection -- South Africa -- St Francis Bay , Restoration ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10611 , http://hdl.handle.net/10948/d1008192 , Beach erosion -- South Africa -- St Francis Bay , Shore protection -- South Africa -- St Francis Bay , Restoration ecology
- Description: The St Francis Bay beach has experienced chronic erosion over the past three decades. This erosion can largely be attributed to the stabilisation of a large coastal dunefield which contributed +/- 80 percent of the sand supply to St Francis Bay. Stabilisation began in 1975 initially using plant cuttings and followed by the development of the Santareme holiday suburb resulting in complete stabilisation by 1985. Effects were felt from the late 1970‟s and since then the beach has retreated at between 0.5 - 3 m.yr-1. Erosion has encroached on beachfront properties since the early 1990‟s, leading to the placement of 3-4 m high unsightly rock revetments along much of the beach. Where properly maintained these structures have proved successful in protecting the properties behind, however exacerbated erosion of areas in front and adjacent to these structures is evident. Currently no dry beach is present at high tide for most of the year, leading to a significant reduction in beach amenity value. Several technical studies to investigate remediation of this beach erosion problem have been conducted since the early 1990‟s. This study includes investigations into the processes and dynamics of the existing environment and evaluation of the effectiveness and impacts of several elements of a hybrid approach to coastal protection and amenity enhancement for St Francis Bay beach. This proposal incorporated: Multi-Purpose Reefs (MPR‟s) offshore, for coastal protection and amenity enhancement in terms of surfing; beach nourishment with sand from the Kromme Estuary and dune rehabilitation with appropriate native sand binding species. Extensive fieldwork and data collection were conducted, this included: a series of bathymetric surveys; diving surveys and a helicopter flight; sediment sampling; beach profiling and deployment of a wave/current meter. Analysis of these data provided a greater understanding of the existing environment and dynamics of St Francis Bay and provided reliable inputs for numerical modelling. Numerical and physical modelling was conducted to assess the existing processes and conduct MPR design testing. In addition calibrated hydrodynamic modelling of the Kromme Estuary was conducted in order to assess the impacts of sand extraction from the large sand banks within the mouth of the Kromme Estuary for use as beach nourishment. Comparison of bathymetric survey data collected by the author in 2005/06 with survey data collected by the South African Navy Hydrographic Office (SANHO) in 1952 suggest a major loss of sand from the bay, with a volume difference of some 8.8 X 106 m3 calculated. Greater losses were measured between 10-15 m water depths, with shallow areas of +/- 5 m water depth, remaining more stable. This can be attributed to the presence of shallow reef and rocky substrate through much of the bay at this depth range. Monthly RTK GPS survey data from September 2006 to September 2007 indicates a total loss of 40 000 m3 over this period with the greatest losses measured along the northern part of the beach. The greatest losses were measured after large long period waves from a southerly to south-easterly direction occurred in conjunction with equinox tides in mid March 2007. Sediment sampling at over 100 locations within the bay indicated a high percentage of reef (26 percent) and fairly consistent grain size in the fine to medium size class throughout much of the beach, bay and large sand bank within the estuary. While the majority of the South African Coast is exposed to the predominant south westerly winds and waves, St Francis Bay‟s orientation means that waves from a south easterly to easterly direction dominate. The results of the detailed numerical modelling of the hydrodynamics agree with previous calculations and modelling results which concluded that strong unidirectional longshore currents occur along the headland due to the oblique angle of wave incidence and the close to parallel angle of wave incidence along the beach leads to weak longshore currents of variable direction. Erosion along St Francis Bay beach is a result of cross-shore erosion due to large waves from a southerly to easterly direction. Detached breakwaters are the most effective form of coastal protection in these environments and MPR‟s offer additional benefits over traditional breakwater structures. Results of empirical calculations and numerical modelling indicate that the MPR‟s will provide effective coastal protection through the processes of wave dissipation, wave rotation, salient formation and alteration of nearshore circulation. Physical modelling results allowed the MPR design to be assessed and refined in terms of surfing amenity enhancement and construction constraints. In addition numerical modelling results indicate that impacts due to the extraction of up to 600 000 m3 of sand from the lower Kromme Estuary result in highly localised velocity reduction, mainly limited to the extraction areas. The calculated rate of sediment influx into the lower Kromme Estuary indicates that limited extraction, in the order of 20 000 – 40 000 m3 per year, should be sustainable in the long term. Sedimentation of the lower estuary over recent years has had negative recreational and ecological impacts, through reduced navigability and water exchange respectively. Therefore both the estuary and beach systems prove to benefit from this approach. Although not investigated in detail as part of this study, evidence from numerous projects worldwide indicates that foredunes help to trap wind-blown sand on the beach and form a buffer to storm erosion, therefore dune rehabilitation with native sand-binding plant species was recommended as the third element of the proposed remediation of St Francis Bay beach.
- Full Text:
- Date Issued: 2008