An examination of the application of a geographical information system to rural development planning in Shixini Location, Transkei
- Authors: Whisken, Jarrell Braden
- Date: 1996
- Subjects: Rural development projects -- South Africa -- Transkei -- Shixini -- Planning , Shixini rural development project , Geographic information systems
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4830 , http://hdl.handle.net/10962/d1005505 , Rural development projects -- South Africa -- Transkei -- Shixini -- Planning , Shixini rural development project , Geographic information systems
- Description: Digital geographical information systems (GIS) are tools for handling spatial data. Initially developed in First World countries, the technology is fast being taken up as a tool for handling spatial information by many Third World countries. GIS has been used for any number of applications involving spatial data, one of its primary uses has been in various planning fields where the advantages offered to planners by the technology have been highlighted by a number of publications and studies. GIS has been actively used as an urban planning tool in South Africa since the mid-1980s, (Vosloo 1987) however its use as a tool for rural planning has not developed to the same extent. As early as 1986 reference was made to the possible advantages offered by GIS to rural planning in South Africa (Fincham 1986). Despite this early recognition, the use of GIS in the rural planning sphere remains negligible. This study examines the. possible reasons for this by attempting to answer the question, "is GIS appropriate to rural planning in South Africa?" A number of approaches to rural planning are practised in South Africa. This study examines the appropriateness of applying GIS to one of these approaches, rural community development planning. Components of the study included i) an examination of the issues affecting the use of GIS in the rural development field, achieved through the use of a literature and questionnaire survey and ii) a case study examining the feasibility of incorporating GIS as a tool to the Shixini Development Project, Transkei. The study does not examine the intricacies of rural development theory, but it does acknowledge the fact that the approach employed by an organisation to rural development will have important implications concerning the use of a GIS in a project. The approach adopted to a project affects amongst others the administrative structure, the planning process, the flow of spatial data and its use, and consequently the possible role of GIS. The Shixini Rural Development Project was classified as a community development project, and as a result the study concentrates on this approach to rural development. This may limit the study to a particular planning process, however most rural case studies will have certain aims and factors which are unique to its situation. In order to place the results of the Shixini case study in a wider context the results of the study are linked to the questionnaire and literature survey. From this basis the usefulness of GIS in the rural development sphere was examined. Available literature on GIS indicates that the majority of problems associated with GIS rarely reside with the technology itself but rather with its supporting mechanisms. The study identified and concentrated on these support mechanisms, both at the project level and what is referred to in the study as the operating environment in South Africa. The results of the study revealed that a number of problems exist with regard to the attitude with which GIS is regarded in development organisations. It was found that these attitudes are legitimately based on a number of problems associated with incorporating the technology into project based organisations. It was concluded that GIS was appropriate to rural community planning, but is presently limited to certain aspects of the planning process and possibly to certain applications.
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The development of the hydraulic biotope concept within a catchment based hierarchical geomorphological model
- Authors: Wadeson, R A (Roy A)
- Date: 1996
- Subjects: Stream ecology -- South Africa Stream measurements -- South Africa Hydrology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4826 , http://hdl.handle.net/10962/d1005501
- Description: This thesis develops a technique for the identification, classification and quantification of instream flow environments. These features have been traditionally referred to as 'habitats' by lotic ecologists, in this research they are termed 'hydraulic biotopes'. The hydraulic biotope is the lowest of six nested levels of a hierarchical geomorphological model. This model has been developed as a tool to assist river managers, researchers and conservationists to categorise or classify rivers with respect to their geomorphic characteristics. Each level of the model provides data at a different level of resolution. This ranges from the broad scale catchment data to the site specific 'habitat' or hydraulic biotope data. Although this thesis is primarily concerned with the development of the hydraulic biotope, the interaction of all catchment variables needs to be recognised. Detailed analysis of hydraulic biotope data in the Buffalo River are presented within the broader hierarchical model. Consultation with lotic ecologists, together with a review of ecological literature, emphasised the need for a standardised terminology for the classification of ecologically significant instream flow environments. At present a fairly haphazard 'habitat' classification tends to be carried out by most researchers, this often leads to confusion in the identification and naming of different hydraulic biotopes ('habitats'). This confusion is exaggerated by the sharing of terminology between lotic ecology and fluvial geomorphology, usually for the categorisation of different types of features. A review of the ecological literature emphasises the importance of flow hydraulics within a river to describe the distribution of biota. The hydraulic variables considered to be most significant include velocity and depth. As river morphology directly determines the prevailing distribution of depth, velocity and substratum, it is obvious that there are important links to be made between fluvial geomorphology and lotic ecology. This thesis explores the potential of the hydraulic biotope as a tool to help develop those links. This thesis presents a standardised classification matrix for the identification of hydraulic biotopes. The matrix is simply based on water surface characteristics together with channel bed substratum. The validity of this matrix is tested by statistical analysis of hydraulic variables quantifying flow conditions within the various hydraulic biotope classes. Data is presented from four different river systems, each representing a different sedimentological environment. Where possible the influence of discharge has been considered. Results from more than 3000 data points show that hydraulic biotopes have distinct hydraulic characteristics in terms of velocity-depth ratio, Froude number, Reynolds number, 'roughness' Reynolds number and shear velocity. These hydraulic indices represent flow conditions both as an average within the water column, and near the bed. Statistical analysis shows that the hydraulic characteristics of the various hydraulic biotope classes are relatively consistent both within different fluvial environments and at different stages of flow. Unlike the morphological unit in which the hydraulic biotope is nested, in stream flow environments are shown to be temporally dynamic. Using the classification matrix as a tool for identification, hydraulic biotopes identified at one discharge are shown to be transformed from one class to another as a response to change in stage. The pattern of transformation is shown to be consistent within different sedimentological environments. An examination of the associations between hydraulic biotopes and morphological units demonstrates that, although some hydraulic biotopes are common to all morphological units (backwater pools, pools and runs), some features have specific associations. In this study rapids were found to be prevalent in bedrock pavement, bedrock pool and plane bed morphology, while cascades, chutes and riffles were common to plane bed, step and riffle morphology. Results from this research indicate that the hydraulic biotope, within the hierarchical geomorphological model, has the potential to aid the prediction of channel adjustment and associated 'habitat' (hydraulic biotope) transformation in response to changes in flow and sediment yield. These are likely to become increasingly important issues as South Africa strives to maintain a balance between the development of water resources to meet the needs of the rapidly expanding population, whilst at the same time maintaining the fluvial environment for sustainable use.
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