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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.
1

The use of magnetic susceptibility measurements to delineate wetlands in KwaZulu-Natal, South Africa.

Watson, Megan. January 2002 (has links)
The aim of this research was to investigate the possibility of using soil magnetic susceptibility to differentiate wetland soil from non0wetland soil, thereby enabling the identification of a wetland boundary. The initial methodology to test the viability of using magnetic susceptibility for wetland delineation was carried out at nine sites in three areas of Kwazulu-Natal, South Africa. Changes in vegetation were used to identify the permanently, seasonally and temporarily wet zones at each site to provide a quick indication of the various boundaries. At least one transect was studied at every site, extending from the outer edge of the temporary zone to the water's edge. Magnetic susceptibility readings, soil samples and/or elevations were taken in each zone. It was found that the magnetic susceptibility readings could be used to differentiate between the various wetland zones but boundaries were not identified due to the reconnaissance nature of the work, a specific protocol had yet to be discovered. This methodology was a reconnaissance phase to assess the potential of using soil magnetic susceptibility. A second methodology was designed specifically to identify a wetland boundary. The wetland zones were identified using vegetation indicators from the South African field procedure for delineating wetlands. Magnetic susceptibility readings were done on transects perpendicular to the suspected boundary and a critical value was identified. A magnetic susceptibility boundary was marked according to the critical value and verified by taking readings along transects parallel to it on both sides. The boundary was then identified using South African field procedure according to soil indicates. The soil data showed a similar boundary to the magnetic susceptibility boundary but indicated a 'boundary zone' of approximately l2m in width rather than a specific line. A final methodology was planned to improve the resolution of the magnetic susceptibility boundary. A grid was laid out over a strip through the wetland including the boundary area on both sides. This was to provide accurately spaced points at which to take magnetic susceptibility readings and elevations. The critical value, a value that separates wetland from non-wetland soil, was identified and verified using soil indicators. The field procedure was more difficult to carry out than using the magnetic susceptibility sensor, yet both methods identified the same boundary with a resolution of about 3m. This initial study demonstrates the potential for using magnetic susceptibility for wetland delineation. Although the results at the final site proved the method to be successful, it was not suitable for use at all sites and the results were often difficult to interpret. Limitations include factors such as plinthic horizons close to the soil surface and shallow, rocky soils. Thus further research is required before magnetic susceptibility can be used to delineate wetlands in KwaZulu-Natal, South Africa. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2002.
2

The geomorphology of wetlands in the upper Mooi River catchment, KwaZulu-Natal.

Longmore, Jennifer Lyn. January 2001 (has links)
Wetlands are now recognized as being an integral component of the physical landscape. Geomorphology has recently been recognised by wetland scientists as being of fundamental importance in wetland genesis, maintenance and evolution, thereby providing the context for informed, effective wetland management and conservation. At present there exists a paucity of geomorphological wetland research in South Africa. A hydro-geomorphic approach was adopted to attain an understanding of wetland genesis, distribution and functioning of a range of different palustrine wetland systems in the upper Mooi-River Catchment of KwaZulu-Natal. The physical, chemical and landscape-morphological characteristics of wetland soils were investigated to interpret the processes operating within those wetland systems. Both field and laboratory work suggest that wetland creation and maintenance in the upper Mooi River catchment may be attributed primarily to climatic factors, landscape position, landform and geological characteristics. These factors were found to cumulatively control the hydrological characteristics of wetlands, which impart an important influence on internal wetland conditions. While soil properties do not appear to be a primary factor in the establishment of these wetlands, they are nevertheless found to be important in the regulation of the hydrological dynamics of wetland systems. The close interdependence between wetlands and the surrounding landscape and the hydrological cycle is evident in the wetland systems investigated. Geomorphic processes within wetlands such as overbank flooding, overland flow, sedimentation, piping, leaching, soil swelling, shrinkage and cracking and channel incision and dynamics were found to be important variables in determining the nature and internal characteristics of wetland systems. In several of the systems investigated, all of the above mentioned processes were operative, while in other systems, a number of these processes were either insignificant or absent. Canonical Variate Analysis indicated that while commonalities exist between the palustrine wetland systems investigated in this study, significant differences were found between different groups. This supports the argument that a subclassification of the palustrine system into five different palustrine wetland types is warranted. While the scope of the present research did not allow for an extensive investigation of suitable methods of rehabilitation, the study suggests that an understanding of geomorphic process and wetland dynamics will be beneficial to wetland management and conservation as a whole. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2001.
3

Aspects of the structure and functioning of the vegetation of the Hlatikulu Vlei.

Guthrie, Iain Andrew. January 1996 (has links)
Hlatikulu Vlei, situated in the foothills of the Natal Drakensberg, is one of the priority wetlands in KwaZulu-Natal, occupying an area of 733 Hectares. The importance of Hlatikulu Vlei lies in its functions to store water, regulate stream flow and attenuate floods, as well as to provide suitable habitat for wildlife and grazing for livestock. Hlatikulu Vlei is a threatened system and has suffered the effects of human mismanagement. Forty-nine percent of the vlei has been classified as disturbed or destroyed, mainly due to the construction of two large dams and past drainage of vlei to facilitate pasture planting. The effects of grazing and fire on the plant communities has been considerably less. Vegetation communities at Hlatikulu Vlei have similarities with those at Ntabamhlope Vlei. The main plant communities present at Hlatikulu Vlei are: vlei grassland, sege-meadows, bulrushes and reedswamp. Species compositions of the mixed sedge and grass sedge-meadow community have a notably higher species diversity than similar communities sampled at Ntabamhlope Vlei and the mires at Highmoor. Soil type and moisture content are shown to be the most significant environmental factors determining the distribution of plant communities and species within the vlei. A wetland re-establishment and rehabilitation programme in the Hlatikulu Crane and Wetland Sanctuary has been effective in allowing many wetland plants to become reestablished. The sanctuary communities bear greater similarity to the sedge and rush sedge-meadow community, than the mixed sedge and grass sedge-meadow communities that were originally present. This is also reflected in the seed bank. All three Southern African crane species (Blue, Wattled and Crowned Crane) and fourteen species of waterfowl have been recorded in the Hlatikulu Crane and Wetland Sanctuary since the wetland rehabilitation programme. The waterfowl play a role in the dispersal of seeds into the sanctuary, particularly those of Schoenoplectus decipiens and Eleocharis dregeana and are in part responsible for the return of certain wetland plants to the sanctuary. The flooding of soils, the fluctuating water level and the soil type related to hummocks and to channels are shown to be responsible for the location of Cyperus denudatus, Arundinella nepalensis and Aristida junciformis in differing positions in the channels and on the hummocks and are also responsible for the maintenance and functioning of the hummocks and channels. Seed banks on the hummocks are similar to seed banks in the channels, however the extant vegetation on the hummocks is distinctly different to that in the channels. Certain species represented in the channel seed bank are being excluded from surviving to maturity. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1996.
4

Public participation in wetland rehabilitation with refrence [sic] to long-term management and sustainability : a case study of Hlatikulu and Ntsikeni.

Nxele, Innocent Zibonele. January 2007 (has links)
Within wetland rehabilitation projects there has been limited research that focuses on the level and nature of participation by local people, such as individuals from communal areas and landowners from private farms. The overall aim of this study was to analyze the level and nature of participation with specific reference to the holistic long term management and sustainability of wetland rehabilitation projects in Hlatikulu and Ntsikeni, KwaZulu-Natal Province, South Africa. Qualitative and quantitative research methods were employed in this study to examine the level of stakeholder participation in the projects. The Hlatikulu and Ntsikeni projects were undertaken on private land and government land (nature reserve) respectively. The World Overview of Conservation Approaches and Technologies (WOCAT) Framework was applied to analyze the level and nature of participation by different stakeholders that were involved in the selected projects. The study revealed that not all stakeholder groups participated in each and every phase of the projects. In Hlatikulu there was a moderate level of participation from the management of private land, but a limited degree of local participation from the Nsonge community. This, to some extent is attributed to the lack organization in the Nsonge community. There are no structures or authorities through which the process of local participation can be engaged. In Ntsikeni, although the process of continuous local involvement was limited to local Chiefs and some community representatives, the process appeared to be participatory in nature. The selected representatives report back in community meetings and other relevant forums, such as the Ntsikeni Nature Reserve Management Forum, which has been operating successfully for several years. Local people participated in the rehabilitation projects mainly as paid workers, and also in providing advice in the planning processes. For both sites, the results demonstrated that there is a need to enhance and harness active local participation in order to ensure the long term management and sustainability of the Hlatikulu and Ntsikeni wetlands. Within this study, the WOCAT framework was applied to provide insights to two sites, with different land tenure and land use contexts. The results of this study suggest that the WOCAT framework has a high potential to be applied across a diversity wetland rehabilitation sites within South Africa. / Thesis (M.Soc.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.

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