Research On Risk Zoning Of Mountain Torrents Disaster In Hubei Province Based On GIS

Flash floods are distinguished from ordinary landslides and urban waterlogging,as a type of natural disaster that is frightening and opened up a separate field of research.Not only because of the great distress beyond the normal rainfall caused to people's normal life,but also because of its special geographical conditions,instantaneous destruction and rapid large-scale mobility and unstoppable.It makes people feel headache about the containment of mountain flood source,the prediction of the critical time and the rectification after the disaster.As the largest population country in the world,China has a large population density,a wide distribution of mountains,a variety of terrain and complex,and all kinds of disaster prevention facilities are not developed.As a result,since 90 s,the number of deaths caused by flash floods has exceeded 1000 people per year.The average annual economic loss of mountain torrents is over 40 billion yuan,and the proportion is still rising in the past ten years.Flash floods in China has become one of the serious natural disasters,especially the upper reaches of the Yangtze River Basin has become a flood disaster areas,a serious threat to people's lives and property safety,hindering the sustainable development of social economy in the footsteps.Hubei province located in the middle reaches of the Yangtze River,is an important north-south transportation hub,a variety of geomorphic type,have both mountain,hilly and plain terrain.Embraced on three sides by mountains,the middle flat,the basin opened slightly south,making it become a natural platform for raging torrents.So the study of flood disaster risks in Hubei province is to reduce the flood disaster loss,necessary measures to guarantee the safety of people's lives in hilly areas,is of great significance to subtle relationship between nature and human society on science of.Based on the natural environment factors and social economic factors in Hubei Province,this paper takes the villages and towns as the research unit,the danger with precipitation,topography and vegetation as the foundation,and the vulnerability of the population to the economic exposure,vulnerability and disaster prevention and mitigation capacity as the foundation,constructs a reasonable risk analysis index system.In view of the existing risk assessment system of flood disasters in multiplicity,nonlinearity and uncertainty,put forward a comprehensive evaluation model based on trapezoidal fuzzy number and analytic hierarchy process(TFN-AHP),and combined with the grey clustering method,the comprehensive evaluation of the mountain flood disaster area is carried out.Different from the previous reliance on GIS,the risk value calculation is not simply the superposition of each index in GIS grid values,but the logical classification process clear,only the geographic information system as the storage,extraction and data visualization tools.Finally,in accordance with low risk,low risk,moderate risk,high risk and high risk of five levels,with each level of membership is to risk zoning map,and to verify its historical disaster data,show that the zoning results accord with actual,can be effective for each township in flood control work to provide reference.