Flood Risk Early Assessment Of Flood Plain Based On Multi-Source Information Fusion

As we know,floods lead to huge threats to human life and property because floods occur in high frequency with short lead time and have a wide geographical distribution.Almost 50% of the total population are in the range of flood threatened regions.With the rapid increasing frequent of floods,it is one of the most important factor which seriously restrict the sustainable economic development of Wuhan.Hanyang district,Hannan district and Caidian district in Wuhan are selected as study areas.This study analyzes flood risk factors through the flood risk identification method.Identification of flood risk obtains related multi-sourced information through multi-sensors and use Ordered Weighted Averaging(OWA)method to comprehensively evaluate the flood risk.This method effectively improve the availability and accuracy of the evaluation so as to make the evaluation results more flexible.The specific research contents are as follows:(1)this study take factors related to disaster environment,disaster drivers and disaster bearers into consideration.In consideration of flood hazard intensity,social economic vulnerability and disaster prevention and reduction,this study chooses precipitation,topography,CN value,distance from Yangtze river,TWI value,population,GDP,dikes,reservoirs,pump stations as evaluation indicators to establish index system of flood risk evaluation for interested regions;(2)evaluation index data should be collected and then be processed with dimensionless method;(3)this study uses Analytic Hierarchy Process(AHP)to calculate the criterion weights and Maximum entropy programming model to obtain the order weights corresponding to different decision-making risk factor α(the value of α can be 0,0.1,0.3,0.5,0.7,0.9,1);(4)the combination operations of evaluation indexes,corresponding criterion weights and order weights are to be compiled by Python to do research on flood risk evaluation in interested regions and acquire the evaluation results under 7 decision-making risk levels.Results indicate that with different risk coefficient,the main influence factors of the evaluation of flood are different and so are the evaluation results.When the decision-making risk coefficient is equal to 0,flood risk level of the whole region is the lowest.With the increasing of decision-making risk coefficient,flood risk level reduces gradually.When decision-making risk coefficient is equal to 1,flood risk level of the whole region is the largest.From seven decision alternatives,risk level of northwest part of Caidian district is the lowest,The intersection of Yangtze river and Hanjiang river in Hanyang district and the southern part of Hannan district have a higher level of flood risk.The main reason is that northwest part of Caidian district is mountainous,and it has high terrain and large relative altitude standard deviation which lead to low flood risk.Regions near Yangtze river and Hanjiang river are affected by the uplifting and decanting of water,which prevents the releasing of the flood so as to increase the probability of flood hazard.This study summarizes flooding events in Wuhan over years and validate the above-mentioned conclusions and the evaluation results are in consistent with reality.