Ontwikkeling van hulpmiddels vir die bestuur en beplanning van 'n stedelike vloedvlakte: 'n GIS toepassing

[摘要] English: The occurrence of floods early in 2000 shows that flood damage research for betterassessmentand mitigation measures of the impact of floods is always necessary. Floodswere always and will always be a problem in South Africa. Floods caused damages ofR150million in one day at Ladysmith (Beeld. 28/02/1996). Losseswere not only financial.but social losseswere experienced as well. The death toll from days of driving rain andresulting floods soared above 50 yesterday and left thousands of people homeless...(BusinessDay.16/02/1996).To limit the impact of future floods. the planning and management of flood plains is veryimportant. Recently. the approach of disaster management has changed from reactiveto proactive. The problem in South Africa is that the necessary communication systemsand institutional framework does not exist. Furthermore. government institutions do nothave the necessary knowledge and tools to execute disaster management effectively.The aim of this study (Chapter 1).was to develop systemsand tools that can address theabove-mentioned problems and to test the developed tools in a study area.As discussed in Chapter 2. the study area along the Swartkops and Chatty Riversin theEastern Cape was a suitable area because of the diversity of land uses. A completesurvey was done. In the case of the Swartkops River the land uses include industrial.commercial and residential. Along the Chatty Riverthe land usesare mainly residential.In Chapter 3 a system for the management of South African flood plains was developed.To do this. flood policies of other countries were studied. Elements of the flood plainmanagement systemare:�?a flood plain management committeee flood studies�?flood plain management studies.and�?flood plain management plansIn Chapter 4 the development of a computer model for the calculation of potential flooddamage was discussed. Another application of the model is the evaluation of possibleflood damage mitigation options for financial effectivity thereof. To develop this model itwas necessary to study models that were developed internationally. The three models oftwo international institutionsthat were studied were developed by the USArmy Corps ofEngineersand the Australian National University. The inputs of TEWA(a computer modelfor the calculation of Tangible Economic flood Water damages Assessment)that weredeveloped from these models, include flood damage functions, land use data,hydrological and geographic data.The model was tested in Chapter 5, by executing the activities of the flood plainmanagement systemand using the model to calculate the potential flood damage andevaluating the mitigation options. Options that were evaluated were derived fromdiscussionswith role-playersin Uitenhage and Despatch.Flood damage was calculated for the different land usesand combined to get the totalflood damage. Damage to the residential sector of Uitenhage, Despatch and Sowetoon-Sea were calculated first. Afterward, damage to the commercial sector of Uitenhageand Despatch and industrialdamage to Uitenhage was calculated.Two options, namely the building of a flood levee and flood proofing were evaluated inUitenhage and Despatch. Theresultsindicated that flood proofing was the best option forindustriesin Uitenhage and a levee will have the most benefits for Despatch. It must beremembered that some assumptionshave been made and that can limit the use of theresults.Thestudy has achieved itsgoal to develop a flood plain management systemthat can beused in South Africa to mitigate the impact of floods

[发布机构] University of the Free State