Doctoral Degrees (Institute for Groundwater Studies (IGS))

Permanent URI for this collection

http://hdl.handle.net/11660/434

Browse

Browsing Doctoral Degrees (Institute for Groundwater Studies (IGS)) by Author "Dennis, Stefanus Rainier"

Now showing 1 - 1 of 1
  • Thumbnail Image
    ItemOpen Access
    Development of a decision tool for groundwater management
    (University of the Free State, 2007-05) Dennis, Stefanus Rainier; Van Tonder, G. J.
    English: Water in South Africa is becoming a scarce and important resource and therefore has to be managed and protected in order to ensure sustainability, equity and efficiency. The SAGDT is designed to provide methods and tools to assist groundwater professionals and regulators in making informed decisions concerning groundwater use, management and protection, while taking into account that groundwater forms part of an integrated water resource. The SAGDT is spatially-based software, which includes: • A GIS interface to allow a user to import shape files, various CAD formats and georeferenced images. The GIS interface also provides for spatial queries to assist in the decision-making process. The GIS interface contains default data sets in the form of shape files and grid files depicting various hydrogeological parameters across South Africa. • A risk assessment interface introduces fuzzy logic based risk assessments to assist in decision making by systematically considering all possibilities. Included risk assessments relate to the sustainability of a groundwater resource, vulnerability of an aquifer, pollution of a groundwater resource (including seawater intrusion), human health risks associated with a polluted groundwater resource, impacts of changes in groundwater on aquatic ecosystems and waste site impact on an area. • Third-party software such as a shape file editor, an interpolator, a georeference tool, a unit converter and a groundwater dictionary. • A report generator, which automatically generates documentation concerning the results of the risk assessment performed and the input values for the risk assessment. • A scenario wizard for the novice to obtain step by step instructions in setting up a scenario. All case studies presented in this thesis is available in the scenario wizard. • The SAGDT allows problem solving at a regional scale or a local scale, depending on the problem at hand. This thesis discusses the origin, research, development and implementation of the SAGDT. Case studies are included to demonstrate the working of the SAGDT. They include: • Vunerability (Fish River Lighthouse) • Waste Site (Bloemfontein Suidstort) • Sustainability (De Hoop) • Mine (Van Tonder Opencast) The SAGDT relies heavily on the expertise of hydrogeologists, assumptions and approximations of real world conditions. Together with the heterogeneities present in groundwater systems it is impossible to guarantee the accuracy of the methodologies and this must be taken into consideration.