The Integration Of Flood Risk Assessment Model Based On GIS Data

Floods are one of the frequent occurrence of natural disasters, especially for cities nearby rivers, flood dike crash will cause great losses, flood risk assessment have played a important role in flood control planning, flood control projects, flood detention basin manage and many other aspects, it is one of the most important non-structural measures for flood control.Flood risk assessment carried out mainly on the regional flood analysis, simulation flood losses under a given frequency flood conditions. Human capacity to flood is a major factor that can not be ignored in flood risk assessment, through flood control engineering measures we can achieve flood controlling and reduce exposure to flood(ie submerged scope, depth),through flood control non-engineering measures we can improve the capacity to respond to flood and enhance social adaptability.This paper summarizes the research results in flood risk assessment, building a flood risk assessment GIS database, use loosely coupled way to integrate hydrology models and GIS based on GIS platform, finally realize the reaches of Hanjiang River Basin Flood Risk assessment, innovation and research result of this paper is mainly reflected in the following sections:First, subdivide flood risk assessment model into flood frequency model, flood model,flood loss models three sub-models, and discusses the principles and calculation methods of these sub-models.Second, the flood damage assessment, using the loss curve as a benchmark loss curve,combined with the study area inside the building height and property distribution amending them, got the sensitivity curve corresponds to the study area, Combined Flood Warning time situation that is adaptive curve amending them again, and finally got the study area for flood depth- loss curve(fragility curves). Property loss from the buildingcombined with flood inundation model calculated that exposed the depth distribution of the situation, the use of GIS spatial overlay analysis on this basis, to simulate various frequencies caused by flooding in the study area distribution.Third, the introduction of the principle of geographic information systems and development components ArcObject, combined with Geodatabase based flood risk assessment database, discusses out dike flood and flood damage assessment of programming methods, including the "seed spread Law" and "dichotomy Newton" algorithm.Fourth,choosing the Han River lower basin as a research area, considering the flood control engineering measures(dike) and non-structural measures(warning time), build the model followed in accordance with the flood frequency, flood model, the order of flood loss models to calculate the Han River downstream flood risk assessment, and gain the flood loss rate distribution of 10-year flood conditions.