| With the continuous change of the global climate and the acceleration of urbanization,extreme rainfall events in cities have gradually increased,and rainstorm and flood disasters have become one of the main natural disasters affecting regional social and economic development,people’s lives and property safety.In the field of disaster research,disaster risk assessment is an extremely important non-engineering measure to deal with disasters.The assessment results can provide a scientific basis for relevant departments to formulate disaster prevention and mitigation plans,and can also quickly identify the spatial distribution of risks for emergency management departments and then make decisions.Provide important help.This paper takes Shaanxi Province as the research area,based on remote sensing data,gridded geographic background data,spatialized social and economic data,etc.,and uses ArcGIS’s spatial data processing,spatial analysis and model building functions to carry out flood disaster risk assessment and zoning.The research results are as follows:(1)Analysis on the driving force of flood disaster impact factors.According to the occurrence of flood disasters in Shaanxi Province,the historical survey results of flood disasters were counted,and 10 types of driving factors were finally selected to quantitatively analyze the impact of each driving factor on flood disasters.The geographic detector model was used to analyze the driving force of flood disaster factors.,precipitation is the direct cause of flood disasters,and slope is the basic condition for flood disasters.Unreasonable human activities aggravate the occurrence of flood disasters.The combined effect of multiple factors on flood disasters will increase the frequency of flood disasters.(2)Build a flood risk index evaluation system in Shaanxi Province.According to the actual situation of Shaanxi Province,based on the research results of previous scholars,combined with the principles of comprehensiveness and availability of data,we choose to construct a flood disaster assessment method in Shaanxi Province based on flood disaster exposure,risk,vulnerability,and disaster prevention and mitigation capabilities.A total of 12 evaluation indicators are selected,including population density,gross regional product,slope,river density,precipitation,cultivated land area,population of old and young,flood defense capability,density of shelters,monitoring capability,medical assistance capability,and residents’ self-rescue capability.As a secondary index,a risk index evaluation system is established.(3)Determination of risk indicator weights.The Analytic Hierarchy Process(AHP)method is established based on the four parts of the analytic hierarchy process(AHP)based on the establishment of the system hierarchy,the construction of the judgment matrix,the single-level ranking and the consistency test of the judgment matrix,and the combination weighting method and the factor analysis method are used to determine the flood disaster The index weights are then used to analyze the flood disaster risk using Fuzzy Comprehensive Evaluation(FCE)and the modeling function of ArcGIS.(4)Flood and waterlogging disaster risk assessment in Shaanxi Province.Taking into account the perspective of geographical research,this paper builds a flood disaster risk assessment model with the help of the idea of superposition and synthesis in geographic layers.The 500m×500m grid unit is combined with the city administrative unit to carry out risk assessment.The flood disaster risk level of the municipal administrative unit is divided by the method,and the following conclusions are obtained through the calculation of the flood disaster risk assessment model in Shaanxi Province:The risk of flood disasters in Shaanxi Province as a whole showed a distribution of "from south to north,decreasing in turn",and showed the characteristics of "sheet" and "band" distribution.The largest distribution area is the low-risk area,the high-risk area is the smallest,and the low-risk area and the high-risk area are roughly equal in size.The risk levels of cities in southern Shaanxi are mainly medium and above,and the main cities in high-risk areas are Shangluo and Ankang;Cities in northern Shaanxi mainly present low-risk and low-risk levels;Guanzhong area mainly presents low-risk,low-risk and medium-risk.On the basis of classification,it proposes flood risk management and optimization strategies in Shaanxi Province,establishes an early warning system for waterlogging,enhances residents’ awareness of disaster prevention,and has a clear division of labor between management departments and various government departments to jointly prevent them. |
