Research On Flood Loss Analysis Method Of City And Countryside

Disasters present periodicity and randomness in our country, where complicated terrain, climate differences and rainfall distribution inequality in the time and space bring frequent flood to large affected area and wide spread range. Most of the floods in China are caused by heavy rains concentrated in April-September. Owing to great flood losses annually and uncertainty of the affected area, it is necessary to strengthen region flood control and disaster alleviation measures, in which flood loss evaluation provides important basis for disaster prevention and mitigation. The paper aims at discussing loss evaluation method for residential and farmland suffered or suffering floods inundation in city and countryside, developing query system for rapidcalculation and fasttips of flood loss in the affected areas, and all of which have many practical applications.Loss assessment is divided into three steps in this paper:flood risk analysis, flood vulnerability analysis and flood loss evaluation. Flood hazard analysis was conducted based on GIS, obtaining submerged depth distribution and inundated area distribution under different depth of survey region. Rural flood vulnerability analysis and rural flood loss evaluation can be briefly characterized as follows:ascertain of assets value,vulnerability curve drawing on the basis of the existing research material, search for lossrate according to the submerged depth, loss evaluation according to the evaluation model and comparative analysis of results as for the building and indoor property, all these steps compose rural housing flood loss evaluation;vulnerability model selection, vulnerability curve drawing, loss evaluation of crops (rice and corn) according to the evaluation model and comparative analysis of results as for crops, all these steps compose flood loss evaluation for rural crops.The single level fuzzy comprehensive evaluation method is applied to hazard level evaluation, vulnerability grade evaluation and risk rank evaluation of urban flood. Based on the administrative division of Tianjin map, draw the risk rank map of Tianjin, with combinations of GIS. Choose corresponding loss model and loss evaluation model for urban flood loss evaluation.In order to make sure the loss evaluation results can be used for decision analysis and the realization of human-computer interaction, the flood loss evaluation and inquires system based on ArcGIS Engine is being developed in this paper,using object-oriented programming language Visual C++, which possesses friendly interface, convenient evaluation and realizes the crops and buildings (including indoor property) loss evaluation calculation of the survey region and information query based on the attribute.The research results of this paper were applied to flood loss analysis of Liaoning and Tianjin, the analyzing and comparing results between computed data and record data owning higher satisfaction.Visualization technology, GIS and flood loss evaluation was combined in this paper for developing the loss evaluation system. On the one hand we can make full use of the space analysis function of GIS for flood loss evaluation, on the other hand, the application of visualization technology makes obtainment of flood loss situation in survey region more quickly and directly for the decision-making departments.