De Villiers, G du TViljoen, M. F.Booysen, Herman Jacobus2017-11-072017-11-072001-05http://hdl.handle.net/11660/7439English: The occurrence of floods early in 2000 shows that flood damage research for better assessmentand mitigation measures of the impact of floods is always necessary. Floods were always and will always be a problem in South Africa. Floods caused damages of R150million 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 and resulting 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 very important. Recently. the approach of disaster management has changed from reactive to proactive. The problem in South Africa is that the necessary communication systems and institutional framework does not exist. Furthermore. government institutions do not have 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 the above-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 the Eastern Cape was a suitable area because of the diversity of land uses. A complete survey 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 plain management systemare: • a flood plain management committee e flood studies • flood plain management studies.and • flood plain management plans In Chapter 4 the development of a computer model for the calculation of potential flood damage was discussed. Another application of the model is the evaluation of possible flood damage mitigation options for financial effectivity thereof. To develop this model it was necessary to study models that were developed internationally. The three models of two international institutionsthat were studied were developed by the USArmy Corps of Engineersand the Australian National University. The inputs of TEWA(a computer model for the calculation of Tangible Economic flood Water damages Assessment)that were developed 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 plain management systemand using the model to calculate the potential flood damage and evaluating the mitigation options. Options that were evaluated were derived from discussionswith role-playersin Uitenhage and Despatch. Flood damage was calculated for the different land usesand combined to get the total flood damage. Damage to the residential sector of Uitenhage, Despatch and Sowetoon- Sea were calculated first. Afterward, damage to the commercial sector of Uitenhage and Despatch and industrialdamage to Uitenhage was calculated. Two options, namely the building of a flood levee and flood proofing were evaluated in Uitenhage and Despatch. Theresultsindicated that flood proofing was the best option for industriesin Uitenhage and a levee will have the most benefits for Despatch. It must be remembered that some assumptionshave been made and that can limit the use of the results.Thestudy has achieved itsgoal to develop a flood plain management systemthat can be used in South Africa to mitigate the impact of floodsAfrikaans: Die voorkoms van vloede vroeg in 2000toon dat vloedskadenavorsing nooit as ontydig en onnodig geag moet word nie. Vloede is en bly Onprobleem in Suid-Afrika. Na beraming het vloedwater in die begin van 1996gedurende een dag skade van R150 miljoen in Ladysmith aangerig (Beeld, 28/02/1996). Dit was nie net finansiële skade nie, maar ook sosiale skade. "The death toll from days of driving rain and resulting floods soared above 50yesterday and left thousands of people homeless..." (BusinessDay, 16/02/1996). Om die impak van toekomstige vloede ten opsigte van finansiële skade en lewensverlies tot die minimum te beperk, is beplanning en bestuur van vloedvlaktes uiters belangrik. Verder het die afgelope paar jaar onverandering in die benadering tot rampbestuur in die wêreld en ook in Suid-Afrikaplaasgevind. Die algemene siening isdat in rampbestuur die klem moet verskuif van reaksie tot pro-aksie. Die probleem is egter dat die nodige kommunikasiestelselsen institusionele raamwerke nie bestaan om aan hierdie opdragte uitvoering te gee nie. Verder beskik owerheidsinstellingsnie altyd oor die nodige kennisen hulpmiddels om rampbestuur effektief toe te pas nie. Die doel van hierdie studie (soosgenoem in Hoofstuk 1) was om hulpmiddels te ontwikkel wat bogenoemde probleme kon aanspreek en om die voorgestelde hulpmiddels in 'n ondersoekgebied te toets. Hoofstuk 2 word gewyaan die beskrywing van die ondersoekgebied. Die ondersoekgebied langs die Swartkops- en Chattyrlvier was uiters geskik vir studie omdat die diversiteit van grondgebruike van so Onaard was dat Onvolledige opname onderneem kon word. In die geval van die Swartkopsrivier het die grondgebruike tussen industrieel, kommersieel sowel as residensieel gewissel. In die geval van die Chattyrivier was dit hoofsaaklik residensieel. In Hoofstuk 3 is Onstelsel vir die bestuur van Suid-Afrikaanse vloedvlaktes voorgestel. Eerstens is die vloedbeleide van verskillende lende. naamlik Suid-Afrika, Australië, Engeland en Wallis bespreek. Uit hierdie bespreking en gesprekke met kundiges is 'n stelsel vir Suid-Afrika ontwikkel. Elemente van die vloedvlaktebestuurstelsel is 'n vloedvloktebestuurskomitee. vloedstudies, vloedvlaktebestuurstudies en vloedvlaktebestuursplanne. In Hoofstuk 4 is die ontwikkeling van on rekenaarmodel waarmee die potensiaal vir vloedskade beraam kan word, bespreek. OnVerdere aanwending van die model is die evaluering van moontlike vloedskade-verminderingsmaatreëls vir effektiwiteit en die finansiële haalbaarheid daarvan. Vir die ontwikkeling van die model was dit nodig om ander rekenaarmodelle wat internasionaal gebruik word, te ondersoek. Die drie modelle van twee instansies wat ondersoek is, is dié wat deur die USArmy Corps of Engineersen die AustralieseNasionale Universitieitte Canberra ontwikkel is. Die insette van TEWA(a computer model for the calculation of Tangible Economic flood Water damages Assessment)wat uit hierdie modelle ontwikkel is, kan saamgevat word as bestaande uit vloedskadefunksies, grondgebruiksdata, hidrologiese data en geografiese data. Die model is in Hoofstuk5 getoets deur die aksiesvan die vloedvlaktebestuurstelselsuit te voer en die model te gebruik vir die berekening ven vloeoskode en evaluering van vloedskade-verminderingopsies. Maatreëls wat in dié hoofstuk voorgestel is, is in gesprekke met rolspelersvan die gebied uitgeklaar. evaluering van moontlike vloedskade-verminderingsmaatreëls vir effektiwiteit en die finansiële haalbaarheid daarvan. Vir die ontwikkeling van die model was dit nodig om ander rekenaarmodelle wat internasionaal gebruik word, te ondersoek. Die drie modelle van twee instansies wat ondersoek is, is dié wat deur die USArmy Corps of Engineersen die AustralieseNasionale Universitieitte Canberra ontwikkel is. Die insette van TEWA(a computer model for the calculation of Tangible Economic flood Water damages Assessment)wat uit hierdie modelle ontwikkel is, kan saamgevat word as bestaande uit vloedskadefunksies, grondgebruiksdata, hidrologiese data en geografiese data. Vir die berekening van totale vloedskade vir die gebied is skade per grondgebruik bereken. Skade aan die residensiëlesektor in Uitenhage, Despatch en Soweto-on-Sea is eerstens bereken waarna kommersiële skade vir Uitenhage en Despatch en industriële skade vir Uitenhage bereken is. Twee opsies, naamlik die bou van Onnoodwal en vloedverskansing, is vir Uitenhage en Despatch getoets. Die resultate van die oefening dui daarop dat vloedverskansing die beste opsie vir die nywerhede in Uitenhage is en onvloedwal die mees voordeligste vir Despatch. Dit moet beklemtoon word dat daar aannames gemaak moes word, wat die gebruik van die resultate beperk. Die studie het in sy doel geslaag om ° n vloedvlaktebestuurstelsel te ontwikkel wat in Suid-Afrika gebruik kan word om die impak van vloede te verminder.afFlood damage estimationFlood damage estimation computer modelFlood damage functionsFlood mitigation optionsFlood plain management systemFloodsGeographic Information SystemMulti criteria decision analyzesUitenhage, Despatch and Soweto-on-SeaNatural disasters -- processingGeographic information systemsFloodplains -- South Africa -- ManagementThesis (Ph.D. (Geography))--University of the Free State, 2001ThesisUniversity of the Free State