Evaluation Of Relative Vulnerability Of China’s Flood Disaster Based On Network DEA Model

China is one of the countries with the most serious flood disasters in the world,especially in the Yangtze River Economic Zone.The frequency and scope of flood disasters have expanded.With the rapid development of climate change and social economy,the risk of flood disasters has increased,which has become a constraint on the social economy.Potential factors for sustainable development.Vulnerability,as the core element of risk,reflects the extent to which a region is adversely affected by floods and the ability to mitigate the adverse effects of floods,and is an important element for regional adaptation to climate change.This study defines vulnerability from three categories:narrow,middle and broad.The potential vulnerability of the area before flood disasters is defined as narrow vulnerability,and the vulnerability of areas with short-term response measures when flood disaster occurs is defined as middle.Vulnerability,and the vulnerability of a region that takes human adaptive measures after the occurrence of a flood disaster is defined as generalized vulnerability,and uses a structured vulnerability structure to construct a network data envelopment evaluation model to evaluate the floods in the Yangtze River Economic Zone from 1997 to 2016 Disaster vulnerability,compares narrow sense vulnerability,middle sense vulnerability and broad sense vulnerability index.The research conclusions are as follows:The results of the study are as follows:(1)From 1997 to 2016,the flood vulnerability index of the Yangtze River Economic Belt showed a narrow sense of vulnerability index>broad sense of vulnerability index>narrow sense of vulnerability index,the middle sense of vulnerability index was 56%lower than the narrow sense of vulnerability index,broad sense of vulnerability.The index is 23%lower than the narrow vulnerability index,indicating that social emergency measures and adaptation measures can alleviate the upward trend of the vulnerability index,and the influence of river network density index on the vulnerability index reaches 42%,and the influence of terrain index on the vulnerability index The ratio is 16%.We believe that areas with high river network density and complex terrain are more prone to flood disasters.The excessive urbanization rate and the proportion of the elderly and the weak will increase the vulnerability of flood disasters;(2)From the perspective of the characteristics of time change,the decline of the vulnerability index of the Yangtze River Economic Zone clearly shows that the middle sense vulnerability>the generalized vulnerability,and compared with the generalized vulnerability index of the Yangtze River Economic Zone,the middle sense vulnerability index has dropped by a proportion of 43%,indicating that the short-term emergency measures taken when the Yangtze River Economic Zone encounters flood disasters have a better effect on reducing the vulnerability of the region than the long-term adaptive measures after flood disasters;(3)The scope of application of different vulnerability assessment models is different.The DEA model of structural vulnerability assessment considers the relationship between the internal factors of the system,and the assessment result is usually lower than that of the non-structural DEA model.The result can usually clarify the mechanism and the action of different factors.The degree of importance,rather than structural models,usually assess the vulnerability of the region from the overall system.When there are few data indicators and the mechanism of action is difficult to determine,it can be used as an index of regional vulnerability to determine the degree of vulnerability of the region.Therefore,through the introduction of the narrow,middle,and broad concepts of vulnerability to flood disasters,the existing definition of vulnerability to flood disasters is expanded,the mechanism and importance of influencing factors within the system are clarified,and the difference in vulnerability of flood disasters can be analyzed.The reason and the mitigation effect of social measures on the vulnerability of flood disasters,this research has innovated the existing theoretical system of vulnerability of flood disasters,and can provide theoretical support for flood disaster management.