Flood Risk Assessment Based On Flood Hazard Index Model

With the development of the society and economy,the situation and demand of flood control are also changing constantly.Flood risk assessment is an important non-engineering measures of flood control and hazard reduction,and it is great significance for stability of water safety and water environment.Based on the research status of flood risk assessment at home and abroad,this paper assesses flood risk of Guanzhong Area in different periods to ensure the healthy and sustainable development of regional water environment.The main research methods and conclusions are as follows:(1)This study first illustrated a multi-parameter flood hazard index(FHI)model for assessing potential flood risk areas in the Guanzhong Area,a large-scale urban area in northwestern China.The FHI model consisted of the risk factor and vulnerability factor.The risk factor consisted of the following six parameters: rainfall intensity,flow accumulation,distance from the river network,elevation,surface slope,and geology.The vulnerability factor consisted of the following three parameters: land use,population,economy.The parameter weights were assigned using an analytical hierarchy process.The sum weight of the first three parameters of risk factor accounted for 77.06% of the total risk factor weight and had significant influence on flooding.The weight of land use accounted for 62.32% of the total vulnerability factor weight and had most significant influence on flooding.(2)Flood risk of Guanzhong Area showed high middle and low around.Flood is high risk in the Yellow River,the Weihe River and its tributaries,the northeast of Guanzhong area,and the central Guanzhong Plain.The very high risk area of Guanzhong Area accounted for 5.84% of the total area,which is mainly located in built-up area along river banks and in central Guanzhong Plain.Except in its northeastern part,most of areas on the sides of the Guanzhong Area have low or the lowest flood risks.The very low risk area of Guanzhong Area accounted for 21.55% of the total area.(3)The level of flood risk has not changed greatly for many years,but the spatial distribution and area still fluctuate slightly.The areas of very high,high,middle,and low risk represent an increase,the highest of 0.71%,1.09%,1.37%,1.01% respectively.The expansion of built-up areas and grassland resulted in risk increase in very high and low risk areas.The very high and high risk area accounts for 24% of the total area.It is mainly located in the densely populated,well-developed and large scale built-up area near Guanzhong Plain and the lowlying areas along the river.These areas are closely distributed and need to be closely controlled.The very low and low risk areas account for half of the total area,and their flood risk are small.(4)This paper assessed the flood risk of different periods in Guanzhong Area,which will be more favorable for the effective control,management and use of water resource.It can reduce the hidden trouble of the water environment and water safety.It can promote the rational development of land,city planning policy.This research also offer basis and help for rescuers' rescue work and guides the aid work.