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Masters Degrees (Environmental Science)

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Browsing Masters Degrees (Environmental Science) by Author "Archer, Lynette Deborah."

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    A review of the fluvial geomorphology monitoring of the receiving streams of the Mooi-Mgeni [River] Transfer Scheme Phase 1.
    (2009) Hunter, Alistair Malcolm Scott.; Kotze, Donovan Charles.; Dent, Mark Clifford.; Archer, Lynette Deborah.
    The Mgeni River is the major water resource for the eThekwini Metropolitan and Msunduzi Municipalities. At the end of 2002, the Mooi-Mgeni Transfer Scheme Phase 1, which transfers water from the Mooi River into the Mgeni catchment to augment the water supply to this region, was completed. The interbasin transfer of water resulted in the loss of habitat, erosion of the stream channel and transformation of the riparian zone in the receiving streams. Stream regulation resulting in an altered flow regime is considered the greatest threat to a riverine environment. An Environmental Management Plan (EMP), incorporating fluvial geomorphological monitoring procedures, was implemented to monitor the impact of the transfer on the receiving streams, the Mpofana and Lions Rivers, and to determine the rate and magnitude of erosion. A comparison of the geomorphological monitoring procedure of the EMP with best practice geomorphological monitoring derived from a review of the national and international stream geomorphological literature was conducted in this study. In addition, the implementation of the EMP geomorphological monitoring procedures was described and onsite observations of physical impacts on the receiving streams were completed. The geomorphological monitoring of the EMP included the use of erosion pins, survey of stream cross-sections and fixed-point photography. Photographs and data were collected from February 2003 to June 2006. The comparison of these monitoring methods against stream assessment best practices revealed the strengths and weaknesses of the geomorphological monitoring implemented in the receiving streams. Several key weaknesses were revealed. Firstly, an inadequate number of stream cross sections was included in the monitoring procedures. Secondly, although the erosion pins indicated some general trends in the erosion of the stream channel, they did not give a true impression of the rate and magnitude of change in slope and channel width of the stream, and the location of the erosion pins sites did not take into account the actual direction of flow during transfer as erosion pin sites were selected during low flow conditions. In addition, it was difficult to determine whether the erosion pins had been lost due to erosion or to turbulence. The results were difficult to assess and did not show whether the erosion was localised at the pins or the section of bank or stream profile. Thirdly, analysis of platform changes in the stream channel (e.g. through a comparison of aerial photograph sets) was lacking and no attempt was made to integrate the results from the different methods. Overall, the study concluded that the geomorphological monitoring of the EMP was limited, and it did not highlight the rate and magnitude of erosion in the receiving streams. Based on the findings of this study, recommendations are provided for geomorphological monitoring of the receiving streams of the Mooi Mgeni Transfer Scheme.
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    Identifying the prevalence of and pathways to diarrhoeal disease in rural KwaZulu-Natal and the implications for evaluating the impact of water supply schemes on community health.
    (1999) Archer, Lynette Deborah.; Fincham, Robert John.
    Since the establishment of a democratic South Africa in 1994, a number of rural water supply schemes have been implemented. A specific aim of these schemes is to improve the health of the population. The underlying assumption is that a supply of reticulated water will improve the quality of water used by the community, reduce the exposure of the community to contaminated water supplies, and reduce water related diseases, in particular diarrhoea. This research thesis focuses on two rural water supply schemes in KwaZulu-Natal: Mpolweni and Vulindlela, both being developed by Umgeni Water, the regional water utility. These communities depended variously on rivers, rain harvesting, and springs for their water supply. For sanitation, the majority of people used unimproved pit latrines. This research thesis is based on information gathered from the communities prior to the installation of the water supply schemes. It focuses on the linkage between water supply and health by examining diarrhoeal morbidity as a measurable disease outcome and by identifying possible pathways to the prevalence of diarrhoea. Questionnaire and observational surveys were undertaken of 181 households in Mpolweni and 100 households in Vulindlela. From these surveys, the prevalence of diarrhoea in Vulindlela households was found to be 40.4% and in Mpolweni to be 49%. Children under the age of five years old are the most vulnerable, with 20.1% of children in Mpolweni and 21 .3% of children in Vulindlela reported as having had diarrhoea in the recall period prior to the surveys. The Mpolweni study considered eighty exposure variables, finding an association between diarrhoeal disease and sixteen of these variables (p value < 0.05). The Vulindlela study considered fifty-five exposure variables, of which eight were considered significant (p value < 0.05). In regard to water and diarrhoea: • no association was found between the prevalence of diarrhoea and the source of water in either Mpolweni or Vulindlela. • using water to wash nappies was associated with diarrhoeal disease in Vulindlela. However, it is postulated that it is the faecal contamination in the nappy, rather than the water, that is problematic. No association between water use and diarrhoea was established in Mpolweni. • poor disinfection of stored water supplies was associated with diarrhoeal disease in both Mpolweni and Vulindlela. In addition, the use of plastic storage containers to store water at the household provided additional risk in Mpolweni. However, once the reticulated system is installed, the communities are likely to continue to store water due to a distrust of the reliability of water supply. The above surveys form the baseline for additional studies currently being undertaken by Umgeni Water that are intended to measure the effectiveness of the water supply schemes on community health. However, from this thesis, it is concluded that many of the risk factors associated with diarrhoeal disease in both Vulindlela and Mpolweni will not directly be addressed by the introduction of the water supply schemes.