Study On Risk Assessment And Prevention Of Local Flood Disaster

Flood disaster is one of the natural disasters that do great harm to human society.Its destructive and frequent nature forces us to be prepared at all times.A little carelessness may lead to heavy losses.Except for some local floods,Hunan has not suffered major floods for a long time since the last major flood event in 1998.However,in the summer of 2021,the heavy rain in Henan province made people understand the terror power of flood disaster again.It not only sounded the alarm for us to improve the awareness of prevention,but also warned us that the disaster was not far away from us,and urged us to step up the research on flood disaster prevention and control.Based on the prevention of flood disaster in advance,this paper tries to make clear the level of flood disaster risk in various places of Hunan Province and find effective countermeasures to reduce the risk.Based on the natural risk assessment model,the main social and natural environmental factors affecting flood disaster are classified according to sensitivity,risk,exposure and recovery.Then the vector data is transformed into raster data and the weighted sum of raster data is realized by using Arc Gis technology.Finally,the specific distribution of sensitivity,risk,exposure and recovery of flood disaster in Hunan province is obtained,as well as the flood disaster risk zoning map of Hunan province synthesized by all indicators.Based on the analysis of the zoning map,it is found that:(1)the environmental sensitivity of Hunan province is high in the northeast and central part of the whole,and low in the rest of the surrounding areas,and the high sensitivity is mainly concentrated in the Dongting Lake basin and the Xiangjiang River,that is,the surrounding areas of Yueyang city,Changde city and Changsha city.(2)The distribution of disaster risk in Hunan province is characterized by low risk in the north and high risk in the south,and the area of high risk in different regions accounts for 19.3% of the total area of Hunan province.(3)The area of high exposure area in Hunan province is only12159 ?,accounting for 5.6% of the province,most of which are concentrated in Changsha from the map.(4)In the recovery of disaster prevention and mitigation in Hunan province,the level is closely related to the local economic level.High recovery and high recovery areas in Hunan belong to relatively developed areas,which means that good economy means perfect urban infrastructure.(5)from the comprehensive risk index of flood disasters,Hunan province is a relatively safe area of 70%,in the other thirty percent are relatively dangerous areas,in Changsha,Changde,Xiangtan and Yueyang this four areas at highest risk,as compared with other areas,these areas have in common is mainly low-lying,water resources,and the economic level and population density is relatively high,So it’s at a relatively dangerous level in terms of overall flood risk.Furthermore,according to different risk situations,it is proposed to take targeted monitoring of key areas and scientific planning to adjust the distribution of buildings in high-risk areas.In medium-risk areas,multi-governance will be used to realize joint prevention and control,and flood control facilities will be improved by building DAMS and pipes.Finally,in low-risk areas,suggestions such as publicity and education to improve flood control awareness and returning farmland to lakes to enhance water holding capacity should be implemented,and scientific and flexible methods should be adopted to effectively improve urban flood control management capacity according to local conditions.