Messerschmidt, H. J.Viljoen, M. F.Weepener, Harold Louw2017-11-022017-11-021998-11http://hdl.handle.net/11660/7390English: Viljoen, Du Plessis and Booysen (1995) started in 1992 with the development of a flood damage simulation model (FLODSIM) for the Lower Orange River area. This model was based on GIS technology and was completed in 1994. The main shortcoming of this model was that it was location specific. A successive project was piloted in 1995 for the modification of the model so that it would be generally applicable in flood prone areas. Weiss (1976) already did extensive work on the estimation of flood damage for the Mfolozi floodplain and it was therefore decided to demonstrate the model on the Mfolozi floodplain. A Setup program was written to be able to adapt the model according to the different situations of floodplains. The Setup program prompts the user to indicate the features that should be included in the model and then it guides the user through a series of menus to define the variables that are required to include the specified features. Features that can be included into the model include a DTM, levees, contours, spot heights, cultivated fields, infrastructures and buildings. Flood damage can be computed for cultivated fields, infrastructures and buildings. Other enhancements of the model include programs for the manipulation of levees, loss functions for sugarcane and infrastructure and a program that computes the flooded areas. Programs were also written to speed up the process of acquiring new hydraulic data after levees were added or removed. This includes programs with which topographic data that are required by numerical flood models can be extracted from the DTM and programs with which the hydraulic data that were computed with the numerical flood model can be imported into FLODSIM. An interface with Mike Il was also developed to illustrate the coupling between FLODSIM and numerical flood models. In a literature study that was conducted to investigate different methods for obtaining data it was found that data can either be acquired in digital form from another company or it has to be digitised from maps. When no data are available for the area it may be collected in situ or by means of remote sensing. Remote sensing can also be of great value in updating data such as land use patterns that change over time. The sources that are used to derive DEM data vary from ground surveys, photograrnmetry and existing contour maps to radar or laser altimetry.Afrikaans: Viljoen, Du Plessis en Booysen (1995) het reeds in 1992 begin met die ontwikkeling van 'n vloedskadesimulasiemodel (FLODSIM) vir die Benede-oranjeriviergebied. Hierdie model was gebaseer op 'n GIS-benadering en is in 1994 voltooi. Die grootste tekortkoming van die model was dat dit gebiedspesifiek was. 'n Opvolgprojek is in 1995 geloods om die model so te veralgemeen dat dit toepasbaar op verskillende vloedgeteisterde gebiede kan wees. Weiss (1976) het reeds omvattende werk ten opsigte van vloedskadeberaming vir die Mfolozirivier gedoen en daar is besluit om die gebruik van FLODSIM op die Mfolozi vloedvlakte te demonstreer. 'n Opstellingsprogram is geskryf om dit moontlik te maak om die model aan te pas na gelang van die verskillende situasies in vloedvlaktes. Die opstellingsprogram laat die gebruiker toe om die kenmerke van die gebied aan te dui en lei dan die gebruiker deur 'n reeks menu's om die veranderlikes van elke kenmerk te definieer. Kenmerke wat deur die modelondersteun word, sluit 'n DTM, noodwalle, kontoerlyne, hoogtepunte, landerye, infrastruktuur en geboue in. Programme is ook geskryf om die verkryging van nuwe hidrouliese data te vergemaklik nadat noodwalle bygevoeg of verwyder is. Dit sluit programme in wat die topografiese data wat deur numeriese vloedmodelle benodig word, vanaf die DTM kan genereer en programme waarmee die hidrouliese eienskappe wat deur die numeriese vloedmodelle bereken is, weer ingetrek kan word in FLODSIM. 'n Koppelvlak met Mike 11 is ontwikkel om die koppeling tussen FLODSIM en numeriese vloedmodelle te demonstreer. Ander verbeteringe tot die model sluit programme in vir die manipulasie van noodwalle, verliesfunksies vir suikerriet en infrastruktuur en 'n program vir die bepaling van gebiede wat oorstroom. In 'n literatuurstudie wat uitgevoer is ten opsigte van die verskillende metodes vir die verkryging van data, is gevind dat die data enersyds in digitale formaat vanaf ander instansies gekry kan word indien beskikbaar, of vanaf analoogkaarte versyfer kan word. Indien daar geen data vir die gebied beskikbaar is nie, kan die data in situ of met behulp van afstandwaarneming versamel word. Die bronne wat gebruik kan word vir die skep van DEM-data, wissel vanaf grondopmetings, fotogrammetrie en bestaande kontoerkaarte tot radar- of laserhoogtemeting.enGeographic information systemsNatural disasters -- Data processingInformation storage and retrieval systems -- FloodsDissertation (M.Sc. (Computer Science))--University of the Free State, 1998DissertationUniversity of the Free State