Based On Gis-an Jiang Zhenhong Water Disaster Warning And Damage Assessment Systems

Flood hazard is one of the most harmful disasters, how to reduce flooddamage becomes the main concerned problem in the world. With thedevelopments of social economics, research developing on flood control,multi-discipline influence, and the developments of such technologies ascomputer simulation and Geography Information System (GIS), people haspaid more attention to integrate more subjects to flood hazard defending.Since 1980s, people have done many researches in flood prediction, floodregulation and flood prevention and reduction system in big river andwatershed, but less research in town scale regions. For such towns, syntheticalmeasures of flood prevention, and flood prediction and flood loss evaluationsystem are acquired urgently to reduce the loss caused by flood hazard.The whole town at Anjiang is a canyon basin along with the mainstreamof the Yuanjiang river. The length of the river crossed the Anjiang downtownis about 8.4 km. For many years, the frequency of flood inundation in thetown is high, which seriously threatens the assets of the resident and restrictsthe development of all aspects of social economy at Anjiang. Concerned withthe characteristics of the watercourse of Anjiang, based on the surveyed dataand the hydrological analysis methods, and with the support of GIStechnologis, this thesis has started the research and implementation of theGIS-based system of flood warning and loss evaluation at Anjiang.Based on the practical application background, this thesis analyzes thesystem requirements and objectives, analyzes and designs the overviewstructure of the system, the scheme of system development, and the functionsetc. by using the design methods of structure and module. Based on theanalysis of the data concerned with flood warning and flood loss evaluation,the system database has been designed from the aspects such as dataorganization and data management, and the spatial database suitable for floodwarning and flood loss evaluation has been established. Based on the methodsof terrain modeling, the DEM of the study area has been established by usingGIS software. Such database and DEM provide the data conditions for theanalysis of flood inundation and the evaluation of flood loss.This thesis analyzes the Muskingum River Flow Routing Model and two methods to estimate the parameters of the model, comes up with a floodrouting computation method based on the Water Balance Model, and analyzesanother flood routing computation method based on the Water StationComputation Specification and the Flow Rate Data. Based on the comparisonof the application situation of the above-mentioned three methods in the studyarea, the flood routing computation takes use of the method on account of theWater Station Computation Specification and the Flow Rate Data. Also, thisthesis discusses one method of the simulation of flood surface, and comes upwith and realizes one algorithm of how to compute the flood inundation areabased on raster structure. At the same time, this thesis starts the research of themethod of flood loss evaluation based on GIS spatial analysis technologies.Supported by GIS technologies, this thesis researches the idea andpattern of system integration, and therefore starts the research of the methodsof data process and the implementation of the main modules of the integratedsystem. The idea and pattern of system integration are based on two principles:system being independent to data and attribute data being independent tographic data. The data integration based on uniform data format, mapprojection and coding standard, and the integration and development of thesystem has ultimately been realized. Development of the integrated systemmainly includes following aspects: the control of layers, the querying andediting of graphic attribute data, the management of hydrological data, floodrouting computation, flood inundation, flood loss evaluation, and so on.This thesis focuses on the geography synthetical analysis based on GIS tostart the application research of the flood forecast and flood loss evaluationsystem in the town region scale. Such GIS-based system of flood warning andloss evaluation at Anjiang basically realize the whole procedures from theshort-term flood forecast to the evaluation of flood loss.