Water supply development decision-making in South Africa
- Authors: Preston, Ian Robert
- Date: 2016
- Subjects: Water security -- South Africa , Water resources development -- South Africa -- Cost effectiveness , Water consumption -- Economic aspects -- South Africa , Water-supply -- South Africa -- Management , Water-supply -- South Africa -- Decision making
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1210 , http://hdl.handle.net/10962/d1020848
- Description: Balancing water demand and supply in South Africa involves high levels of uncertainty. The Department of Water and Sanitation (DWS) is responsible for making decisions to either increase water supply or decrease water demand so as to ensure that sufficient water is available, when and where it is needed. However, no retrospective analyses of such decisions have been found. One way to assess such decisions is to evaluate the associated costs and benefits thereof. Therefore the primary aim of this study is to evaluate the costs and benefits of selected water supply options, and of the decision-making associated with those options. In order to achieve this purpose, four case studies were analysed within a mixed-methods research paradigm, which used both quantitative and qualitative methods, including unit reference value (URV) analysis, inter- and intra-case analysis and content analysis to examine the success of the decisions made. The four case studies were conducted on the Inyaka, Nandoni, Berg and De Hoop dams and their catchments. Firstly, estimated and actual project costs were compared using unit reference analysis and inter-case analyses. Secondly, the reduction of mean annual runoff (MAR) caused by invasive alien plants (IAPs) and the cost of clearing them in the dam catchments were evaluated using inter-case analyses. Information thus gathered was used together with data from DWS documentation and the results of interviews with ten key specialists, to analyse the decision-making process that led to the decision to build De Hoop Dam (the most recent case study). The rational decision-making model (RDMM) was used as a framework within which to analyse and evaluate this decision-making process. This study has also demonstrated how the RDMM can be used to assess decision-making associated with water supply development. The results of this study show that there is considerable variation of estimated costs (at the time that the decision to build the dam was taken) in relation to the actual costs of building the dams and that Ministers were not put in a position to understand the full long-term costs or the opportunity costs of the proposed dams. Furthermore, the most recent IAP data (2008) shows that the impact on water security by IAPs could not offset the water security resulting from building each of the four dams. However, if IAP management is not continued in these catchments, the projected reduction of MAR by IAPs will compromise water security within 45 years. Given the almost exponential spread and densification of IAPs, together with their long-term impact on MAR and increased costs of controlling them, it is clear that IAP management should have been factored into water supply decision-making from the outset. In the analysis of the decision to build the De Hoop Dam, the results show that while the decision-making process that culminated in the decision to build the dam did not follow the steps of the RDMM, DWS appears to have followed a somewhat similar approach. It was found that while there was a need for the provision of additional water in the Olifants catchment, this need was overstated and the resulting overestimation caused the scale and size of the dam to be larger than it could and probably should have been. Additionally, it appears that DWS‘s decision to build the De Hoop Dam themselves, rather than having it built by the private sector, may have been less than optimal. It is recommended that, in future decision-making, DWS needs to incorporate multiple alternative options into the same solution, and to ensure that decision-makers are put into a position to make informed decisions, including adequate consideration of externalities. Furthermore, DWS needs to employ decision-making models such as the RDMM to facilitate retrospective analyses to improve their institutional knowledge. Keywords: water resources management, dams, invasive alien plants, decision-making, unit reference values, rational decision-making model.
- Full Text:
- Date Issued: 2016
- Authors: Preston, Ian Robert
- Date: 2016
- Subjects: Water security -- South Africa , Water resources development -- South Africa -- Cost effectiveness , Water consumption -- Economic aspects -- South Africa , Water-supply -- South Africa -- Management , Water-supply -- South Africa -- Decision making
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1210 , http://hdl.handle.net/10962/d1020848
- Description: Balancing water demand and supply in South Africa involves high levels of uncertainty. The Department of Water and Sanitation (DWS) is responsible for making decisions to either increase water supply or decrease water demand so as to ensure that sufficient water is available, when and where it is needed. However, no retrospective analyses of such decisions have been found. One way to assess such decisions is to evaluate the associated costs and benefits thereof. Therefore the primary aim of this study is to evaluate the costs and benefits of selected water supply options, and of the decision-making associated with those options. In order to achieve this purpose, four case studies were analysed within a mixed-methods research paradigm, which used both quantitative and qualitative methods, including unit reference value (URV) analysis, inter- and intra-case analysis and content analysis to examine the success of the decisions made. The four case studies were conducted on the Inyaka, Nandoni, Berg and De Hoop dams and their catchments. Firstly, estimated and actual project costs were compared using unit reference analysis and inter-case analyses. Secondly, the reduction of mean annual runoff (MAR) caused by invasive alien plants (IAPs) and the cost of clearing them in the dam catchments were evaluated using inter-case analyses. Information thus gathered was used together with data from DWS documentation and the results of interviews with ten key specialists, to analyse the decision-making process that led to the decision to build De Hoop Dam (the most recent case study). The rational decision-making model (RDMM) was used as a framework within which to analyse and evaluate this decision-making process. This study has also demonstrated how the RDMM can be used to assess decision-making associated with water supply development. The results of this study show that there is considerable variation of estimated costs (at the time that the decision to build the dam was taken) in relation to the actual costs of building the dams and that Ministers were not put in a position to understand the full long-term costs or the opportunity costs of the proposed dams. Furthermore, the most recent IAP data (2008) shows that the impact on water security by IAPs could not offset the water security resulting from building each of the four dams. However, if IAP management is not continued in these catchments, the projected reduction of MAR by IAPs will compromise water security within 45 years. Given the almost exponential spread and densification of IAPs, together with their long-term impact on MAR and increased costs of controlling them, it is clear that IAP management should have been factored into water supply decision-making from the outset. In the analysis of the decision to build the De Hoop Dam, the results show that while the decision-making process that culminated in the decision to build the dam did not follow the steps of the RDMM, DWS appears to have followed a somewhat similar approach. It was found that while there was a need for the provision of additional water in the Olifants catchment, this need was overstated and the resulting overestimation caused the scale and size of the dam to be larger than it could and probably should have been. Additionally, it appears that DWS‘s decision to build the De Hoop Dam themselves, rather than having it built by the private sector, may have been less than optimal. It is recommended that, in future decision-making, DWS needs to incorporate multiple alternative options into the same solution, and to ensure that decision-makers are put into a position to make informed decisions, including adequate consideration of externalities. Furthermore, DWS needs to employ decision-making models such as the RDMM to facilitate retrospective analyses to improve their institutional knowledge. Keywords: water resources management, dams, invasive alien plants, decision-making, unit reference values, rational decision-making model.
- Full Text:
- Date Issued: 2016
Stratigraphy, geochemistry and origin of the manganese ore deposit in Carletonville, North West province of South Africa
- Authors: Pharoe, Benedict Kinshasa
- Date: 2015
- Subjects: Geology, Stratigraphic Geology--South Africa Geochemistry--South Africa
- Language: English
- Type: Thesis , Masters , Geology
- Identifier: http://hdl.handle.net/10353/11641 , vital:39092
- Description: The Carletonville manganese ore-deposit is a Neogene weathered nodule deposit which was developed on the Early Proterozoic Malmani dolomite succession of the Transvaal Supergroup in Carletonville area, North-West Province, South Africa. The deposits were formed from surficial weathering of the underlying Mn-rich dolomites of the Malmani Subgroup and some were formed from weathered Mn-rich Tertiary alluvial-fluvial sediments. These deposits are currently mineralized and hosted in modern Mn-Fe rich soil profiles and occurs at shallow depths, thus the ore is suitable to be mined by open-cast mining. The study dealt with the stratigraphy, petrology, geochemistry, diagenesis and origin of the ore-deposit. The stratigraphic profile of the manganese ore-deposit was subdivided into 8 zones, namely the (A, B, C, D, E, F, G, and H) zones from the surface downwards. On the basis of variation in mineralogical and chemical composition, nodule grain sizes and the zonation colour, the above mentioned zones were further integrated into the Upper (A and B), Middle (C, D and E) and Lower (F, G and H) Zone, with the I zone, the basement zone, representing the underlying Malmani Subgroup stromatolitic dolomite. The Upper Zone represents organic rich, fine grain silty soil which caps the stratigraphic succession in the mine area. Mineralogically, these zones are depleted in manganese and comprises of hematite, kaolinite, micas and quartz grains, with Mn-Fe coated terrigenous clasts concentrated at the lowermost portion of the B-zone along the contact with the underlying zones. The Middle Zone is characteristically medium to fine in grain sizes with reddish colour due to intense weathering of iron minerals to hematite and is depleted in Ca, Na and Mg bearing minerals as a result of dissolution and leaching and is highly concentrated in quartz and caliche fragments. The Lower Zone is coarse grained with dark, reddish-brown colour. The Middle and Lower Zones comprise mainly of Mn and Fe oxides, clays, quartz, limonite, micas and caliche patches. The concentration of manganese is, however, not consistent in these zones from one borehole to the next, it deviates with topography and depth. The overall stratigraphic succession in the mine area can be described as characterizing of basal stromatolitic dolomite of the Malmani Subgroup, overlain by zone of black, powder-like manganiferous wad which is in turn overlain by weathered Mn-rich Tertiary alluvial-fluvial sediments hosting manganiferous nodules. The whole succession is covered by Quaternary sands. The studies undertaken on grain size analysis for the determination of variation in nodule grain sizes with increasing depth along the profile has indicated a perfect variation trend in grain sizes, where the underlying Lower Zone characterizes of coarse grain fraction whilst the overlying Middle Zone is mainly medium to fine grained and the Upper Zone comprise of very fine silt soil. Statistical parameters were used to classify these sediments under Udden-Wentworth grain size classification scheme. Based on these parameters the samples were classified as pebbles and/or gravel on GRADISTAT program and were found to be moderately to poorly sorted, positively skewed with moderate kurtosis and displays a bimodal distribution. Mineralogical analysis with X-Ray Diffraction and petrographic studies indicates that cryptomelane (KMn8 O16) is the major manganese mineral, whereas pyrolusite occurs as a minor manganese mineral in the mine. Other mineral constituents include hematite/goethite, clay minerals, muscovite, quartz, calcite, limonite with minor amount of heavy minerals. The modal composition studies carried out on the terrigenous clasts which are coated on surface by Mn-Fe oxide concentric laminae indicated their nature to be sub-arkoses and quartz arenites. These clasts are found to occur in association with manganiferous nodules in the mine area, with high concentration experienced at the uppermost portion of the profile below the top soil. The provenance studies indicates the source of these terrigenous sediments from cratonic interior to recycle orogen at low plains with a temperate and subhumid climate and on tropical, humid conditions within an area of moderate to low relief. Based on the geochemical studies, different manganese classification schemes were adopted in this study and inferences were made from geochemical data which indicated supergene and hydrogenous source of the Carletonville manganese nodules suggesting precipitation from weathering residues of Malmani dolomite at passive continental margin of tectonic provenance, with temperate and tropical to humid climatic conditions. The diagenetic features were broadly divided into early, mid and uplift diagenetic stage. Early stage includes sediment consolidation which characterized of cementation and neomorphism in carbonate sediments. This period was followed by mid (burial diagenesis) stage which brought about an increase in tightness of grain packing, loss of pore spaces and thinning of beds due to weight of overlying sediments and selective dissolution of framework grains. Mineral dissolution and replacement were common factors during this stage. In the last diagenetic stage, rocks were uplifted, weathered and unroofed by erosion bringing mineral assemblage including newly formed diagenetic minerals into environment of low temperature and pressure, and high oxygen environment.
- Full Text:
- Date Issued: 2015
- Authors: Pharoe, Benedict Kinshasa
- Date: 2015
- Subjects: Geology, Stratigraphic Geology--South Africa Geochemistry--South Africa
- Language: English
- Type: Thesis , Masters , Geology
- Identifier: http://hdl.handle.net/10353/11641 , vital:39092
- Description: The Carletonville manganese ore-deposit is a Neogene weathered nodule deposit which was developed on the Early Proterozoic Malmani dolomite succession of the Transvaal Supergroup in Carletonville area, North-West Province, South Africa. The deposits were formed from surficial weathering of the underlying Mn-rich dolomites of the Malmani Subgroup and some were formed from weathered Mn-rich Tertiary alluvial-fluvial sediments. These deposits are currently mineralized and hosted in modern Mn-Fe rich soil profiles and occurs at shallow depths, thus the ore is suitable to be mined by open-cast mining. The study dealt with the stratigraphy, petrology, geochemistry, diagenesis and origin of the ore-deposit. The stratigraphic profile of the manganese ore-deposit was subdivided into 8 zones, namely the (A, B, C, D, E, F, G, and H) zones from the surface downwards. On the basis of variation in mineralogical and chemical composition, nodule grain sizes and the zonation colour, the above mentioned zones were further integrated into the Upper (A and B), Middle (C, D and E) and Lower (F, G and H) Zone, with the I zone, the basement zone, representing the underlying Malmani Subgroup stromatolitic dolomite. The Upper Zone represents organic rich, fine grain silty soil which caps the stratigraphic succession in the mine area. Mineralogically, these zones are depleted in manganese and comprises of hematite, kaolinite, micas and quartz grains, with Mn-Fe coated terrigenous clasts concentrated at the lowermost portion of the B-zone along the contact with the underlying zones. The Middle Zone is characteristically medium to fine in grain sizes with reddish colour due to intense weathering of iron minerals to hematite and is depleted in Ca, Na and Mg bearing minerals as a result of dissolution and leaching and is highly concentrated in quartz and caliche fragments. The Lower Zone is coarse grained with dark, reddish-brown colour. The Middle and Lower Zones comprise mainly of Mn and Fe oxides, clays, quartz, limonite, micas and caliche patches. The concentration of manganese is, however, not consistent in these zones from one borehole to the next, it deviates with topography and depth. The overall stratigraphic succession in the mine area can be described as characterizing of basal stromatolitic dolomite of the Malmani Subgroup, overlain by zone of black, powder-like manganiferous wad which is in turn overlain by weathered Mn-rich Tertiary alluvial-fluvial sediments hosting manganiferous nodules. The whole succession is covered by Quaternary sands. The studies undertaken on grain size analysis for the determination of variation in nodule grain sizes with increasing depth along the profile has indicated a perfect variation trend in grain sizes, where the underlying Lower Zone characterizes of coarse grain fraction whilst the overlying Middle Zone is mainly medium to fine grained and the Upper Zone comprise of very fine silt soil. Statistical parameters were used to classify these sediments under Udden-Wentworth grain size classification scheme. Based on these parameters the samples were classified as pebbles and/or gravel on GRADISTAT program and were found to be moderately to poorly sorted, positively skewed with moderate kurtosis and displays a bimodal distribution. Mineralogical analysis with X-Ray Diffraction and petrographic studies indicates that cryptomelane (KMn8 O16) is the major manganese mineral, whereas pyrolusite occurs as a minor manganese mineral in the mine. Other mineral constituents include hematite/goethite, clay minerals, muscovite, quartz, calcite, limonite with minor amount of heavy minerals. The modal composition studies carried out on the terrigenous clasts which are coated on surface by Mn-Fe oxide concentric laminae indicated their nature to be sub-arkoses and quartz arenites. These clasts are found to occur in association with manganiferous nodules in the mine area, with high concentration experienced at the uppermost portion of the profile below the top soil. The provenance studies indicates the source of these terrigenous sediments from cratonic interior to recycle orogen at low plains with a temperate and subhumid climate and on tropical, humid conditions within an area of moderate to low relief. Based on the geochemical studies, different manganese classification schemes were adopted in this study and inferences were made from geochemical data which indicated supergene and hydrogenous source of the Carletonville manganese nodules suggesting precipitation from weathering residues of Malmani dolomite at passive continental margin of tectonic provenance, with temperate and tropical to humid climatic conditions. The diagenetic features were broadly divided into early, mid and uplift diagenetic stage. Early stage includes sediment consolidation which characterized of cementation and neomorphism in carbonate sediments. This period was followed by mid (burial diagenesis) stage which brought about an increase in tightness of grain packing, loss of pore spaces and thinning of beds due to weight of overlying sediments and selective dissolution of framework grains. Mineral dissolution and replacement were common factors during this stage. In the last diagenetic stage, rocks were uplifted, weathered and unroofed by erosion bringing mineral assemblage including newly formed diagenetic minerals into environment of low temperature and pressure, and high oxygen environment.
- Full Text:
- Date Issued: 2015
An investigation into the development of environmental education as a field of practice in South African National Parks
- Authors: Taljaard, Sandra
- Date: 2009
- Subjects: Environmental education -- South Africa National parks and reserves -- South Africa Environmental education -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1603 , http://hdl.handle.net/10962/d1003485
- Description: This study looks at aspects of the development of environmental education in South African National Parks (SANParks), in relation to the emergence of national and organisational policy frameworks. In order to put current environmental education practices into context, the study firstly looks at the historical development line of environmental education in SANParks, as well as in the broader national context. This provides a framework within which the processes of change and development can be traced in terms of social, political and economic influences on an international and national front. The study finds that the promulgation of legislation, including the Constitution, National Acts and various other policies, reflected the trends of thinking and set the pace in a democratic South Africa, which led to the emergence of more explicit processes and refined policies. Popkewitz’s finding, that education emerged in modernity, is used in the study to illustrate this tendency. It finds that these changes in South Africa resulted in the establishment of more structured environmental education processes within SANParks, and led to the expansion, diversification and strengthening of environmental education as a field of practice over time. The study traces significant processes of recontextualisation of international and national environmental education related policies according to the framework established by Bernstein (1980). These processes of recontextualisation were followed in the formulation processes of SANParks policy and strategy documents in the period from 1999 to 2005, and resulted in an official pedagogic discourse for environmental education in SANParks. The study establishes a second level of recontextualisation, that is, the official pedagogic discourse of environmental education in SANParks is recontextualised to a pedagogic discourse of reproduction. The pedagogic discourse of reproduction relates to park practices, where contextualisation within park-based programmes appears to be strong. The park-based programmes resemble a ‘curriculum in practice’, which brings us to Cornbleth’s critical curriculum approach. The study utilises this approach to explore and explain the meaning of the critical perspective taken on curriculum construction and change efforts at park implementation level (Cornbleth, 1990). The study finds that the contextualisation of park programmes and practices lead to variety in park programmes, which adds richness to environmental education programmes and activities, and further highlights the fact that environmental education practices are prolific in national parks. The study also finds that historical and contextual processes associated with specific parks strongly characterise environmental education programmes and practices in those parks, and that partnership programmes, such as the Kids in Parks programme, contribute towards, and enhance the growth of environmental education as a specialised field of practice in SANParks. The study comments on the need for environmental education practices in SANParks to be reviewed and expanded in line with the contemporary approach towards the environment as a social construct of interacting components. These components include the biophysical, social, economic and political dimensions. The study also highlights the need for the recognition and acknowledgement of the long, historical development line of environmental education in SANParks in order to build on established structures in a holistic way. The study further determines a need for strong leadership to successfully expand this specialised field of practice and encourages a participatory approach in the review and further development of this field of practice in SANParks. The study ultimately finds that environmental education in SANParks has a long and rich development profile, which has placed it in a strong position for further development. However, it concludes that there is a great need for a rejuvenated approach, which requires expert knowledge, professionalism and broad based networking approach to enable meaningful expansion within this specialised field of practice.
- Full Text:
- Date Issued: 2009
- Authors: Taljaard, Sandra
- Date: 2009
- Subjects: Environmental education -- South Africa National parks and reserves -- South Africa Environmental education -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1603 , http://hdl.handle.net/10962/d1003485
- Description: This study looks at aspects of the development of environmental education in South African National Parks (SANParks), in relation to the emergence of national and organisational policy frameworks. In order to put current environmental education practices into context, the study firstly looks at the historical development line of environmental education in SANParks, as well as in the broader national context. This provides a framework within which the processes of change and development can be traced in terms of social, political and economic influences on an international and national front. The study finds that the promulgation of legislation, including the Constitution, National Acts and various other policies, reflected the trends of thinking and set the pace in a democratic South Africa, which led to the emergence of more explicit processes and refined policies. Popkewitz’s finding, that education emerged in modernity, is used in the study to illustrate this tendency. It finds that these changes in South Africa resulted in the establishment of more structured environmental education processes within SANParks, and led to the expansion, diversification and strengthening of environmental education as a field of practice over time. The study traces significant processes of recontextualisation of international and national environmental education related policies according to the framework established by Bernstein (1980). These processes of recontextualisation were followed in the formulation processes of SANParks policy and strategy documents in the period from 1999 to 2005, and resulted in an official pedagogic discourse for environmental education in SANParks. The study establishes a second level of recontextualisation, that is, the official pedagogic discourse of environmental education in SANParks is recontextualised to a pedagogic discourse of reproduction. The pedagogic discourse of reproduction relates to park practices, where contextualisation within park-based programmes appears to be strong. The park-based programmes resemble a ‘curriculum in practice’, which brings us to Cornbleth’s critical curriculum approach. The study utilises this approach to explore and explain the meaning of the critical perspective taken on curriculum construction and change efforts at park implementation level (Cornbleth, 1990). The study finds that the contextualisation of park programmes and practices lead to variety in park programmes, which adds richness to environmental education programmes and activities, and further highlights the fact that environmental education practices are prolific in national parks. The study also finds that historical and contextual processes associated with specific parks strongly characterise environmental education programmes and practices in those parks, and that partnership programmes, such as the Kids in Parks programme, contribute towards, and enhance the growth of environmental education as a specialised field of practice in SANParks. The study comments on the need for environmental education practices in SANParks to be reviewed and expanded in line with the contemporary approach towards the environment as a social construct of interacting components. These components include the biophysical, social, economic and political dimensions. The study also highlights the need for the recognition and acknowledgement of the long, historical development line of environmental education in SANParks in order to build on established structures in a holistic way. The study further determines a need for strong leadership to successfully expand this specialised field of practice and encourages a participatory approach in the review and further development of this field of practice in SANParks. The study ultimately finds that environmental education in SANParks has a long and rich development profile, which has placed it in a strong position for further development. However, it concludes that there is a great need for a rejuvenated approach, which requires expert knowledge, professionalism and broad based networking approach to enable meaningful expansion within this specialised field of practice.
- Full Text:
- Date Issued: 2009
Reaction phenomena between Karroo Dolerite and cave sandstone xenoliths in the Bird's River complex
- Authors: Kenyon, A K
- Date: 1976
- Subjects: Volcanic ash, tuff, etc , Igneous rocks -- Inclusions , Sandstone
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4996 , http://hdl.handle.net/10962/d1005608
- Description: Mapping of the north-eastern portion of the Bird1s River Complex revealed that two large xenoliths composed of pyroclastic rocks and sandstone of the Cave Sandstone Stage have reacted with the dolerite. All the reaction phenomena normally associated with Karroo Dolerite are encountered. These are: (a) Metasomatism during the stage of iron enrichment of the dolerite with the production of a pyroxene-plagioclase metasomatic granophyre (b) Metasomatism during the stage of alkali enrichment of the dolerite with the production of a potassium feldspar adinole C c) Assimilation 'vi th the production of contaminated doleri tes Cd) Fusion 'vi th the production of glassy rocks including buchi tes (e) The production of rheomorphic veins
- Full Text:
- Date Issued: 1976
- Authors: Kenyon, A K
- Date: 1976
- Subjects: Volcanic ash, tuff, etc , Igneous rocks -- Inclusions , Sandstone
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4996 , http://hdl.handle.net/10962/d1005608
- Description: Mapping of the north-eastern portion of the Bird1s River Complex revealed that two large xenoliths composed of pyroclastic rocks and sandstone of the Cave Sandstone Stage have reacted with the dolerite. All the reaction phenomena normally associated with Karroo Dolerite are encountered. These are: (a) Metasomatism during the stage of iron enrichment of the dolerite with the production of a pyroxene-plagioclase metasomatic granophyre (b) Metasomatism during the stage of alkali enrichment of the dolerite with the production of a potassium feldspar adinole C c) Assimilation 'vi th the production of contaminated doleri tes Cd) Fusion 'vi th the production of glassy rocks including buchi tes (e) The production of rheomorphic veins
- Full Text:
- Date Issued: 1976
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