Kleynhans, Martin Thomas2006-03-132006-03-132006-03-13http://hdl.handle.net/10539/240Master of Science in Engineering - EngineeringThere have been various threats from upstream catchment developments to the water supply of the ecologically important Nylsvlei floodplain in South Africa. Hydrological modelling of the catchments and unsteady hydraulic modelling of the floodplain (including measured losses to evapotranspiration and infiltration) with biotic links to Oryza longistaminata revealed that existing developments within the catchments have decreased areas suitable for growth of this plant in the Nylsvley Reserve by 9% on average from 1973/74 to 2000/01 compared to the catchment in a virgin state. Construction of the proposed Olifantspruit Dam with environmental flow releases would have reduced these suitable areas by a further 9% on average. Catchment developments were found to have the greatest impact on floodplain inundation in average to dry years and would also reduce the frequency of occurrence of suitable conditions for growth of Oryza longistaminata.340667 bytes1089402 bytes531294 bytes115113 bytes104993 bytes558684 bytes231543 bytes5318493 bytes6416278 bytes388091 bytes1975158 bytes204408 bytes2322997 bytes69086 bytes150511 bytes77059 bytes100922 bytes84748 bytes70429 bytes60574 bytes55004 bytes40642 bytesapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfenimpactenvironmentfloodplainrivernylmodellinghydrologicalhydraulicThesis