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  • 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.
71

The fate of microbial contaminants in the subsurface with a South African case study /

Rajkumar, Yasmin. January 2009 (has links) (PDF)
Thesis (M. Sc. ) - niversity of the Western Cape, 2009. / Includes bibliographical references (leaves 72-79)
72

Harbour reclamation in Hong Kong land production and landuse planning : the environmental perspective /

Cheung, Wai-hung, Tony, January 1997 (has links)
Thesis (M.U.D.)--University of Hong Kong, 1998. / Includes bibliographical references (leaves 63-65) Also available in print.
73

Environmental disturbance and the distribution of Rhinichthys bowersi in West Virginia

Schienker, Brook Elizabeth. January 2007 (has links)
Theses (M.S.)--Marshall University, 2007. / Title from document title page. Includes abstract. Document formatted into pages: contains viii, 113 pages including illustrations and maps. Bibliography: p. 44-45.
74

Consideration for the impact of climate change information on stated preferences /

Barak, Boaz. January 2006 (has links)
Thesis (Ph. D.)--University of Rhode Island, 2006. / Includes bibliographical references (leaves 269-279).
75

Elephants in the Waterberg : impacts on woody vegetation by breeding groups compared with bachelors

Frost, Jennifer Sarah 21 November 2005 (has links)
In May 1994 IFAW funded the relocation of 50 elephants from the Kruger National Park to Welgevonden Private Game Reserve in the Northern Province, South Africa. Impact by the elephants on the vegetation of this reserve has since become a concern. The aim of this study was to quantify impact by the elephants on the woody vegetation by investigating vegetation and habitat use by elephant bachelor and breeding groups. This was determined by comparing resource use between sexes within seasons, and within sexes between seasons. Data were collected at two ecological scales: feeding patch scale and habitat scale. Feeding data were collected from 202 food plots, defined from 161 elephant sightings. In the dry season, when resources are often limited, no difference in feeding patch use was found between bachelor groups and breeding groups. This may suggest a lack of inter-sexual competition and could therefore suggest that the elephant population is currently below carrying capacity. Three habitat types are available to the elephants: plateau, hillslope and valley bottom. Both bachelor groups and breeding groups preferred valley bottom in comparison with habitat availability, in both seasons. When sexes were compared within seasons, in the dry season, bachelor groups used valley bottom more and breeding groups used hillslope more. / Dissertation (MSc (Zoology))--University of Pretoria, 2006. / Zoology and Entomology / unrestricted
76

The environmental impact of seepage from gold mine tailings dams near Johannesburg, South Africa

Rosner, Thorsten 20 December 2007 (has links)
Gold mining in South Africa resulted in vast volumes of waste material, mainly in the form of tailings material. Poor management of most of the tailings dams resulted in the release of acid mine drainage that in some cases caused soil degradation and water contamination underneath and around these sites. Although many tailings dams have been partially or completely reclaimed, their contaminated footprints pose a serious threat to the water quality of the underlying aquifers (e.g. dolomitic aquifers). This study investigated the geotechnical, mineralogical and geochemical parameters of eleven selected partially or completely reclaimed sites situated near Johannesburg. The main objective of the field and laboratory experiments was to assess the pathway of contaminant migration resulting from acid mine drainage from tailings materials through the unsaturated zone into the groundwater system. Comparing extractable contaminant concentrations with a soil standard from literature represents the environmental short-term impact. In contrast, total element concentrations in the soil compared with background values were used to describe the long-term impact or worst-case scenario. Extraction tests have shown that only a minor portion of contaminants (i.e. Co, Ni and Zn) is mobile in acidic soils. This implies that plant growth could be limited because of phytotoxic elements occurring in the topsoils, complicating rehabilitation measures. In addition, the soils often contain anomalous trace element concentrations, providing a pool for future contamination. Buffer minerals will eventually be depleted and the subsequent acidification of the subsoil, could result in the remobilization of contaminants from the subsoil into the groundwater system in the long term. It is important to understand the parameters, which control the balance between retention and mobility of contaminants in soils. Therefore a risk assessment approach would be required for all tailings dams and reclaimed sites to identify those sites, which need rehabilitation and to define the type and extent of remedial measures. Minimum rehabilitation requirements at reclaimed sites could consist of soil management measures such as liming and the addition of organic material and fertilisers to minimise the contaminant migration from the topsoil into the subsoil and groundwater as well as to provide suitable conditions for vegetation growth and future land use. Removal of remaining tailings and excavation of those portions of the soil, which are excessively contaminated, are necessary. Tailings dams which pose a high risk to the environment would require a well-engineered soil and vegetation cover to limit rainfall infiltration into the impoundment, and thus to reduce the oxidation of sulphide-bearing minerals such as pyrite. Long-term monitoring is an absolute prerequisite to ensure the success of rehabilitation, and therefore the safe use of land and water. / Thesis (PhD)--University of Pretoria, 2007. / Geology / Unrestricted
77

Towards a methodology for identifying potential sites for cemeteries

Judge, Richard David Eadie January 2012 (has links)
Due to death being an extremely sensitive issue, the topic of cemeteries and associated environmental impacts is often left outside the mainstream environmental critique. However, this is a topic becoming more prevalent as the population numbers and the death rate increases, while the amount of available land decreases. Recent research has indicated that poorly sited cemeteries may pose a significant threat to groundwater resources with the consequential potential for severe health hazards. This has resulted in the need for a method of determining the acceptability of a given area for the establishment of a cemetery in a South African context. Cemeteries should be sited in such a way as to mitigate potential public health and safety concerns, minimise associated environmental impacts and provide a method of body disposal that is economically viable. This study therefore provides an integrated methodology to identify and assess a given area and rank a number of potential sites, ultimately determining a single cemetery site which proves to be acceptable for the establishment of a cemetery. Cemetery site selection should be based on the factors affecting the pollution potential of a proposed cemetery. These factors were identified and quantified based on research into the mechanisms of cemetery site pollution resulting in a number of fatal flaws and criteria deemed decisive when selecting a potential cemetery site. The assessment of a site with regards to these criteria and fatal flaws is undertaken through the use of GIS analysis software utilising data layers containing information on the site selection criteria, by investigating existing studies, literature or reports relating to the relevant area, or through field investigations. Although these criteria are vital when determining the specific characteristics of a site in terms of its pollution potential, a method of assessing a number of potential sites with regards to these criteria is vital. To this end, a multi-criteria ranking matrix has been developed, allowing for an objective method of assessing individual sites and thus indicating which sites are more suited for the establishment of a cemetery. The ranking matrix identifies a range of values for each criterion, therefore identifying a minimum and maximum allowable value. A site is then assessed with regards to these criteria in relation to the values identified in the ranking matrix. Each criteria is assigned a score according to the site conditions. Once the criteria for each site has been assessed and scored, the results can be tallied allowing the sites to be ranked according to which site proved to be the most acceptable for a cemetery based on the findings of the application of the site selection criteria. The methodology developed in this study is unique to previous studies in that it provides an integrated and staged approach to identifying, assessing and applying the criteria affecting the pollution potential of a cemetery. The methodology also provides a means of ranking a number of potential sites so to determine the most suitable. Furthermore, the criteria deemed as decisive in previous investigations were in most cases not quantified by the relevant authors, therefore leaving many of the criteria values up for interpretation. For this methodology to be affective, all criteria must be quantified therefore identifying maximum and minimum allowable limits for each. This study applies minimum and maximum allowable limits to these criteria, therefore aiding in the ranking process. The integrated methodology developed was then applied to a case study where by the effectiveness in identifying a number of potential cemetery sites could be tested. Subsequent to the application of this methodology to a case study, it was concluded that an additional two criteria, not identified in previous investigations, needed to be assessed to more adequately determine the suitability or otherwise of a site for a cemetery. Ultimately, twelve major criteria have been proposed for use as the basis of the methodology. The methodology and pertinent criteria proposed in this study should be compiled as a standard for planning authorities and consultants to use as a method of determining a number of potential environmentally sound cemetery sites.
78

Towards a model for environmental assessment and management of boreholes in communal areas in Namibia

De Wet, Neil January 1997 (has links)
This was the final statement in a report, prepared for the Namibian Programme to Combat Desertification (NAPCOD), which researched the process, praxis and environmental impacts of borehole provision in communal areas in Namibia (ENGEO, 1997).¹ This dissertation is a response to this concluding statement. It presents a theoretical model which provides a comprehensive yet simple environmental assessment and management framework to inform, guide and manage the provision of boreholes in communal areas in Namibia. The model has been designed to be cost effective, appropriate for its context and 'user-friendly'. Most importantly, the model aims to present a system which would promote principles of sustainability and, consequently, sustainable development in terms of borehole provision in communal areas in Namibia.
79

Environmental evaluation of proposed alternative roads to the Mohale dam

Heydenrych, Reuben January 1993 (has links)
Bibliography: p. 109-111. / This is an academic report submitted in partial fulfilment of the degree Master of Environmental Science. It is written to demonstrate the competence of the writer in undertaking work in the field of Environmental Impact Assessment. The main purpose of the report is the comparative evaluation of two proposed alternative roads, the "Western Access Route" (WAR) and the "Least Cost Alternative Route" (LCAR). Since this is an academic report, it will not be used as a decision-making document and it will not be submitted to the proponent of the alternative roads.
80

NM2002 impact assessment : impact assessment report

Lochner, Paul January 1992 (has links)
Bibliography: p. 94-95. / The purpose of this report is to: * assess the biophysical and socio-economic impacts of closure of De Beers Namaqualand Mines (DBNM) * provide preliminary suggestions for mitigation measures. DBNM anticipate that they will close in approximately 10 years' time. By the year 2002, all diamond deposits which are currently economically viable to mine on a large-scale would have been exploited. Closure is anticipated to have a significant impact on DBNM employees, their households, and towns where the households of employees live. Furthermore, closure is anticipated to have a significant impact on the Namaqualand economy. Therefore, DBNM commissioned the EEU to undertake an assessment of the impacts resulting from mine closure, to ascertain the effects on their employers and their affected households and communities. Through discussions with DBNM the scope for this assessment was established: * Briefly to describe the current biophysical, social and economic environments in Namaqualand and identify different trends in the region. * To assess in detail the socio-economic impacts resulting from the closure of DBNM. In addition, this report considers the impacts on the biophysical environment resulting from the closure of DBNM, because the socio-economic well-being of employees from rural areas of Namaqualand and Transkei is intrinsically linked to changes in the biophysical environment. Lastly, this report also contains preliminary suggestions for mitigating the impacts of closure.

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