• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 118
  • 8
  • 1
  • 1
  • Tagged with
  • 152
  • 152
  • 152
  • 88
  • 64
  • 57
  • 46
  • 32
  • 32
  • 23
  • 22
  • 20
  • 19
  • 18
  • 18
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Community-based environmentalism in transitional South Africa: social movements and the development of local democracy

Buchler, Michelle 30 January 2017 (has links)
A dissertation submitted to the Faculty of Arts at the University of the Witwatersrand, Johannesburg, in partial fulfilment for the degree of Master of Arts. Johannesburg 1995. / This report explores co llect+ve ect+on around opposition to a propo..;ed hazardous waste 1andf t 11. Of concern ;s the role that social movement organisations and social movement activists, organising around environmental issues, can play in entrenching a participatory, non-racial democracy in South Africa's present transitional political phase. The analysis makes use of theories of social movements which argue that collective action is rooted in previous cycles of mobilisation, and that the role of social movement entreprenbJrS or activists is crucial in coll,ctive action mob'l Hsat ton. Data was collected through the use of participant observation and semi-structured interviews, Various documentary sources were also used. This report argues that mobilisation around environmental issues can best be understood by locating such mobilisation in the heritage of previous cycles of mobilisation, most notably in the period of the 19805. Furthermore, this report highlights the fact that the structure and form of ~he transitional state at national, regional and local levels presents certain constraints with regard to the extension and entrenchment of participatory democracy, Finally, it will be argued that while the Chloorkop Coalition demonstrates the pctent ial that environmental issues have for uniting communities across traditional racial and ideological barriers, it ;s not clear whether a lasting cross~racial cooperation can be achieved. / MT2017
62

Use of remote sensing and GIS in a risk assessment of gold and uranium mine residue deposits and identification of vulnerable land use

Sutton, Malcolm William 29 April 2013 (has links)
A research report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Environmental Science Johannesburg, November 2012. / Acid rock drainage (ARD) and dust are potential consequences of gold and uranium mine residue deposits (MRDs) on the Witwatersrand basin. Urbanisation has taken place around mines and, with the curtailing of mining activities and clearing of land previously covered by MRDs, there is pressure to use this land for residential, industrial and agricultural purposes. However, mining companies historically were not required to provide pollution control measures and there is evidence for contamination of land and water. Thus, there is a need to prioritise contamination sources for mitigation and to understand the extent of contamination and potential risks associated with different categories of land-use on mining land. The aim of my study was to conduct a first-order risk assessment to aid in identifying vulnerable land use in the vicinity of gold and uranium mining, and prioritising MRDs, including footprints, for mitigation. To achieve this I constructed a Geographical Information System (GIS) using publicly available spatial data, and then tested the usefulness of historical aerial photographs and remote sensing imagery for mapping MRDs and impacts of MRD origin under Highveld conditions (i.e. a seasonal climate with summer rainfall and annual evapotranspiration of >2.5 times mean annual precipitation). The Ekurhuleni Metropolitan Municipality (EMM; 1923 km2) is an area of extensive historical mining with major urbanisation, while retaining areas for agricultural land use; thus it was selected as a representative study site. I used a numerical rating scheme, which combined a number of parameters in two separate stages to calculate a risk index. The first stage involved the classification of hazards associated with MRDs while the second involved an assessment of land use vulnerability based on exposure pathways and proximity. Historical aerial photographs (1938, 1964 and 2003) and the Chamber of Mines (CoM) Dump Indexes were used to identify and classify MRDs in terms of basic geotechnical properties, current status and historical failure. Multi-spectral data, acquired over two years (2002 and 2003) in two seasons (spring and summer) by the TERRA satellite’s Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor, were used to compile thematic images, indicating potential contamination of surrounding land. It was intended that a zone of influence could be distinguished for each MRD enabling me to rate the hazard severity. The thematic images I selected included primary minerals (pyrophyllite and chlorite), secondary minerals (copiapite and jarosite), an indicator of uranium-bearing ore (referred to as mincrust) and the normalised difference vegetation index (NDVI). These minerals were chosen as potential indicators of different transport routes of contaminants and I tested their associations with different features and land use. I also tested for seasonal differences in the detection of these minerals, and used NDVI to examine the masking effect of active vegetation. I found GIS to be well suited for combining the various forms of spatial data and providing information about MRDs, aqueous pathways, proximity to vulnerable land uses and impacted areas. However, I found that the potential severity of the hazards posed by each MRD, as indicated by a zone of influence, could not be determined from aerial photographs and ASTER alone. I therefore utilised the findings expressed in the literature survey to assign ratings for the different classes of MRDs. The vulnerability assessment was also supplemented by literature review to rate land uses based on human exposure pathways. I determined that MRDs (including footprints) cover 4.1% of EMM, with slimes dams, totalling 3.5%, occupying the majority of this area. I found that 64% of slimes dams had failed prior to 2003 and I plotted a further 0.6% of EMM covered by visible mine residue spillage. Fifty three percent of MRDs were situated within 100 m of drainage lines or old wetlands, while 52% of these (i.e. 27% of the total) had been constructed in the watercourse. I also found that 15% were constructed on dolomites. Informal settlements were located on or bordering 6% of MRDs, with 41% of MRDs within 1 000 m. Eighty eight percent of MRDs were found within 1 000 m of formal residential areas, 71% within 500 m, and formal settlements were located on or bordering 5% of MRDs. Twenty three percent of MRDs were located within 500 m of agricultural land, while 35% were within 1 000 m; and industrial land use was on 9% of MRDs (footprints), with 40% of MRDs being within 500 m of industrial areas and 61% within 1 000 m I found that chlorite did not provide a ‘signature’ of gold and uranium mine residue, whereas the other four minerals did. I also found that, of the two seasons examined (spring and summer), the best time to take an ASTER image to detect mineral signatures of gold and uranium mine contamination is after a few dry days following the first spring rains. For this reason, I used the ASTER taken in late October (spring) 2003 to examine associations with pathways and land use. I found more pyrophyllite and copiapite on industrial and business land use than background, which I suggest is associated with the settling of windborne dust on large and flat roofs; although, in the case of copiapite this could be related to the oxidation of settled wind blown pyrite material. I found jarosite to be a reliable indicator of mine residue, which, together with mincrust, helped me identify contamination in former agricultural holdings, which are now a township. Although, chemically undefined, mincrust was a useful indicator of contamination, as I found it to be reliably detected on MRDs (including footprints), mine residue spillage, wetlands and other contaminated sites, and absent from known uncontaminated sites. Furthermore, it was not necessarily masked by active vegetation, whereas copiapite, jarosite and pyrophyllite were. Mincrust was also detected on irrigated agricultural land with an odds ratio of between 10 to 36 times greater than for rain-fed. Consequently, the most likely pathway for mincrust is the aqueous. The mincrust signature, together with historical aerial photographs, also assisted me to identify historical mining along Black Reef outcrops, through detection in a wetland upstream of known mining activities. The culmination of my study was a risk class and index for MRDs from which ‘risk maps’ were produced. These maps provide a guide to the level of risk posed by each MRD to the surrounding land use. Of the total 287 MRDs (including footprints) identified in the EMM, 50% were classified lower-risk; 40% medium-risk; 10% higher-risk and 0% as much higher risk. The lower-risk MRDs were predominantly rock dumps, whereas the higher-risk MRDs were slimes dams. The findings from my study will contribute to meaningful recommendations for future land use and enable mining companies, landowners, developers and government to allocate their resources judiciously (i.e. appropriate to the level of risk). The results of this study have been published as: Sutton, M.W., Weiersbye, I.M., Galpin, J.S and Heller, D., 2006. A GIS-based history of gold mine residue deposits and risk assessment of post-mining land uses on the Witwatersrand Basin, South Africa. In: A. B. Fourie and M. Tibbett (eds.), Mine Closure 2006: Proceedings of the 1st International Seminar on Mine Closure, Perth, ISBN: 0-9756756-6-4, pp. 667–678 (Appendix I). Sutton, M.W. and Weiersbye, I.M., 2007. South African legislation pertinent to gold mine closure and residual risk. In: A.B. Fourie, M. Tibbett and J. Wiertz (eds.), Mine Closure 2007: Proceedings of the 2nd International Seminar on Mine Closure, Santiago, ISBN: 978-0-9804185-0-7, pp. 89–102 (Appendix II). Sutton, M.W. and Weiersbye, I.M., 2008. Land use after mine closure – Risk assessment of gold and uranium mine residue deposits on the eastern Witwatersrand, South Africa. In: A.B. Fourie, M. Tibbett, I.M. Weiersbye and P.J. Dye (eds.), Mine Closure 2008: Proceedings of the 3rd International Seminar on Mine Closure, Johannesburg, ISBN: 978-0-9804185-6-9, pp. 363–374 (Appendix III).
63

Using an inferential model to estimate dry deposition of SO2 and NOX (as NO2) in Lephalale in the Waterberg-Bojanala priority area

Phala, Raesibe Nelvia 19 January 2016 (has links)
A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science June 2015 / Lephalale is the home of Matimba, one of Eskom’s coal-fired power stations. Matimba is the biggest power station with a dry cooling system in the world. There are other industries (including coal mines) currently in operation in close proximity to the station. This industrial area is expected to grow as more industrial activities are planned for the following years. These activities will aggravate the levels of air pollution and possibly result in it being a “hot spot” for air pollution. The impact of air quality on health is covered by the National Ambient Air Quality Standards (NAAQS), but the impact of air quality on the terrestrial and aquatic ecosystem is not known. Therefore, this study focuses on the deposition of nitrogen oxides (NOx) (as nitrogen dioxide (NO2)) and sulphur dioxide (SO2) within Lephalale in the Waterberg-Bojanala Priority Area. Additionally, inter-annual variability of NOx and SO2 ambient concentrations and back trajectories of air masses were analysed. The study obtained ambient air quality data and meteorological data from Eskom for the period 2008–2012, while additional meteorological data were obtained from the Agricultural Research Council (ARC) and the South African Weather Service (SAWS). An inferential model was used to estimate the dry deposition flux of SO2 and NOx (as NO2), and the Hybrid Single Particle Langrangian Integrated Trajectory (Hysplit) Model was used to cluster back trajectories of air masses. The results of the seasonal dry deposition velocities of SO2 (0.17 to 0.23 cm/s) and NOx (0.10 to 0.15 cm/s) (as NO2) were higher in summer and lower in winter. They were also within the magnitude of the deposition velocities found in previous studies in the Highveld. The high deposition velocities in summer were attributed to photosynthetically active vegetation, turbulence and solar radiation. However, seasonal dry deposition fluxes of SO2 and NOx were higher in winter across the years. The higher flux values in winter were attributed to higher ambient concentrations of the trace gases. Additionally, the annual dry deposition flux of SO2 ranged between 0.43 and 0.67 kg S ha-1 yr-1, while NOx (as NO2) ranged between 0.84 and 1.05 kg N ha-1 yr-1 over the period studied. The annual deposition flux values found in the current study are lower than those found in previous studies in the Highveld. This difference could be because of the lower ambient concentrations of SO2 and NOx observed in this study. There is an inter-annual variability of the ambient concentrations of SO2 and NOx during the period 2008–2012. However, the difference is not large or statistically significant. The dominant direction of the back trajectories of air masses is east and southeast across all seasons for the entire period of 2008–2012. This lack of seasonal pattern in back trajectories and source regions cannot explain the seasonal changes in ambient concentrations (SO2 and NOx). Hence, climatic factors (e.g. change in weather) or seasonal changes in combustion source intensity must be responsible.
64

An assessment of the social impacts of water pollution on children in informal settlement : the case of Kliptown informal settlement, Soweto, Johannesburg

Kamusono, Jennifer Tadzei 09 1900 (has links)
The study investigated the causes of water pollution in Kliptown, an informal settlement 17km south of Johannesburg. The study further examined the impact of water pollution, sanitation and inadequate and low quality water provision on children’s social life, health and well-being in informal settlements. The subject of water pollution due to inadequate water supply and sanitation is one that brings a lot of debate, due to the overwhelming impacts it has on children’s social life as well as their health. In informal settlements, social impacts arising from inadequate water supply and sanitation such as the prevalence of water-related diseases like diarrhoea, skin rashes and eye infections have become a permanent feature. This study aimed at assessing the social impacts of water pollution in Kliptown’s Tamatievlei, Mandela View and Valentine Village informal settlements. It also looked at the factors that contribute to the social impacts of water pollution and propose recommendations on how to minimise the social impacts of water pollution on children in Kliptown’s informal settlements. The study applied a mixed method approach, utilising exploratory and descriptive questions to extrapolate both qualitative and quantitative data, which was also presented in quality and quantity form. Outcomes of the investigation indicated that diarrhoea is a major waterborne disease that affects children, mostly under-five years of age, in the informal settlements and that children sometimes missed school due to their being treated for diarrhoea and other water-related illnesses. It was also found that children lived in unhygienic conditions with smelling bucket system toilets and rotting garbage. The study established that children congregated for water at water points for long periods and in the process, they were deprived of time to take part in other social activities. The study recommends mitigating inadequate, low quality water supply, water pollution and sanitation in an integrated manner to gradually eliminate the negative social impacts on children’s social life, health and well-being in Kliptown informal settlement. / Environmental Science / M.Sc. (Environmental Management)
65

The quality of water entering Loskop Dam, Mpumalanga, South Africa.

Moyo, Stanley. January 2013 (has links)
D. Tech. Chemistry / The increase in industrialisation in South Africa has led to an increase in coal mining and coal utilisation in Mpumalanga. This has resulted in the deterioration in the quality of water upstream of Loskop Dam. Little or no information is available on the occurrence or fractionation of trace metals in sediments, which are reservoirs for pollutants. Furthermore, no information is available concerning the occurrence of polycyclic aromatic hydrocarbons (PAHs), known for their carcinogenic and mutagenic effects, in rivers in the area. The possible impact of leaching of elements and organic compounds from South African coals has not been exhaustively researched. The general objectives of the study were to: 1) assess the impact of potentially toxic metals and organic compounds leaching from coal, on the quality of surface waters via simulated leaching experiments; 2) determine the extent of pollution by trace metals and polycyclic aromatic hydrocarbons of the Olifants, Klein Olifants and Wilge rivers, at selected points in the upper catchment area; and 3) identify and apportion sources of polycyclic aromatic hydrocarbons in the sediment samples from the study area.
66

Optimising fall out dust monitoring at a cement manufacturing plant.

Joubert, J. M. (Jacobus Marthinus) January 2012 (has links)
Thesis (MTech. degree in Environmental Health)--Tshwane University of Technology, 2012. / Fall out dust sampling and monitoring is becoming one of the preferred methods to determine dust pollution impact from industries/or mines on the receiving environment. Fall out dust monitoring is a useful and cost effective method of providing trend analysis of dust deposition over a period of time. It also provides an indication of the main areas of dust generation and can be conducted for both health and nuisance purposes.The aim of the study was to develop a positioning guideline for fall out dust monitoring equipment in order to optimise the existing fall out dust programme.
67

An investigation into the negative external impact of water pollution, public policy options and coping strategies --with specific references to the Lotus River Catchment area

Moses, Mariana January 2005 (has links)
The main purpose of this study was to assess the negative external impact of water pollution upon water resources and the users thereof within urban areas.
68

A policy analysis of cleaner technology : a case study of Mondi Limited.

Mokoena, Kgauta Sylvester. January 2003 (has links)
The pollution problems resulting from industrial production activities result in the deterioration of our natural environment. That is why something needs to be done in order to preserve our environment. Conservation alone is not enough. Development is needed. Waste minimisation through applying Cleaner Technologies can help the country in the reduction of waste production and improve industry's environmental management processes. This study was based on an investigation into the adoption of Cleaner Technology. The study argues that elements of Cleaner Technology and the application of tools and strategies to practice Cleaner Technology are very useful for any industry. The costs of Cleaner Technology to companies cannot be compared with the benefits they can get from adopting Cleaner Technology. Mondi Limited concentrates on the product element of Cleaner Technology. It applies the recycling and re-use strategies in or~er to achieve product modification and input substitution. The organisation and knowledge elements are very strong and supportive to the technique element that is used at the Mondi Paper Mill. These three elements contribute to the increased efficiency, improved quality of intended products and waste minimisation through re-use and recycling. The question emerges about what government can or should do in return to companies like Mondi since they contribute towards the sustainability of our natural resources. / Thesis (M.Soc.Sc.)-University of Natal, Pietermaritzburg, 2003.
69

Waste and port reception facilities.

Difeto, Phyllis Motsatsi. January 2010 (has links)
Internationally, shipping, boating and ancillary services are seen as significant contributors to degradation of the marine environment, affecting water quality, habitats and coastal amenity. As a result, it is important to ensure good practice with regard to safety issues when discharging or handling such wastes while vessels are in the port's jurisdiction. The international standards for regulating the prevention of marine pollution through ship generated waste are clearly outlined primarily in the United Nations Convention on the Law of the Sea 1982 ("UNCLOS") and the International Convention for the Prevention of Pollution from Ships1973 as amended by the Protocol of 1978 ("MARPOL 73/78"). The proposed study will explore compliance to MARPOL 73/78 Convention's requirement for governments to ensure the provision of adequate port reception facilities capable of receiving ship board residues and mixtures, containing oil, noxious liquids or garbage, without causing undue delay. The paper further reviews the implementation of the Conventions in the European Union and South Africa as it aims to provide a profile of the availability of waste reception facilities to assess their effectiveness in addressing the problem of marine pollution through ship generated waste. It is concluded that a variety of South African legislation is also applicable to marine pollution, but inadequately enforced. Further, that there was a considerable range of legislation intended to protect the North Sea and European waters in general from marine pollution but marine pollution from vessels is still considered to be a significant problem. In conclusion, it is recommended that South Africa should urgently develop effective mechanisms to monitor the enforcement oflegislation adequately. / Thesis (M.Com.)-University of KwaZulu-Natal, Durban, 2010.
70

An investigation into the negative external impact of water pollution, public policy options and coping strategies --with specific references to the Lotus River Catchment area

Moses, Mariana January 2005 (has links)
The main purpose of this study was to assess the negative external impact of water pollution upon water resources and the users thereof within urban areas.

Page generated in 0.1098 seconds