Flood And Waterlogging Disaster Risk Assessment And Disaster Mitigation Strategies In The Yellow River Basin

With global warming,sea level rise and urbanization,extreme precipitation occurs frequently around the world.As a "severe disaster area" since ancient times,under the dual pressures of the continuous warming and humidification process in northern my country and the growth of population and economic scale,the overall flood disaster in the Yellow River Basin has intensified.Therefore,this paper focuses on the research on the risk assessment of flood disasters in the Yellow River Basin,and constructs a flood risk assessment model in the Yellow River Basin based on the two dimensions of the degree of danger(natural factors)and social vulnerability(social factors).Spatial analysis method to evaluate flood disaster risks at different scales such as river basins,provincial administrative regions,and municipal administrative regions.Finally,from the perspective of reducing the degree of flood risk and reducing social vulnerability,a flood mitigation strategy in the Yellow River Basin is proposed.The main research contents and results are as follows:(1)The degree of risk of flood disaster is determined by two dimensions: the degree of risk of disaster-causing factors and the sensitivity of the disaster-pregnant environment.Select relevant indicators such as precipitation intensity,rainstorm frequency,historical flood frequency,terrain,river network and vegetation coverage.The weights determined by the analytic hierarchy process are weighted after normalizing the indicators.The results show that the degree of flood risk increases from northwest to southeast,and radiates outward with the river network as the high value center.The downstream danger is the highest,the upstream northern Qinghai-Tibet Plateau has the lowest flood risk,and the upstream southern Qinghai-Tibet Plateau has the highest degree of danger compared to the north.(2)The social vulnerability of flood disasters is determined by two dimensions: the vulnerability of the disaster-affected body and the ability to prevent and reduce disasters.Population vulnerability,economic vulnerability,per capita GDP,average fiscal budget revenue per 10,000 people,and average number of beds in health institutions are selected.and other related indicators,based on the weights determined by the AHP,the indicators are normalized and then weighted.The results show that the social vulnerability to flood disasters in the Yellow River Basin shows an increasing trend from north to south,and the social vulnerability to flood disasters in municipal areas is significantly lower.In each county,the vulnerability of the affected bodies in the downstream is slightly higher than that in the upper and middle reaches,and the disaster prevention and mitigation capacity of the municipal district is about twice that of the county.(3)Flood disaster risk is determined by two dimensions,the degree of danger and social vulnerability.Based on the comprehensive calculation of the disaster risk assessment model,it is found that the overall flood risk level in the Yellow River Basin presents an increasing distribution from northwest to southeast,and the risk near the river network is prominent..The high-risk areas are mainly concentrated in the middle and lower reaches,because of the large and concentrated rainfall in the middle and lower reaches,the low-lying and flat terrain,and the concentrated population and economic density;the lowest-risk areas are in the Ningxia Plain.Among the nine provinces through which the Yellow River Basin flows,the high-risk areas that should be paid attention to are the southwest of the Shandong section and the west of the Henan section;the low-risk areas are the Gansu section,the northern Ningxia section and the western Inner Mongolia section.Among the capital cities along the Yellow River,the high-risk areas that should be paid attention to are Jiyang District of Jinan,Jinshui District of Zhengzhou,and Zhongyuan District of Zhengzhou;the low-risk areas are Hohhot,Yinchuan,Lanzhou,Xining and other cities.According to the result of the risk level,the flood disaster mitigation strategy is proposed from two aspects: reducing the degree of flood risk and reducing social vulnerability.Reduce the degree of flood risk by building infrastructure: strengthen monitoring and early warning;dredging river network and water system;strengthening ecological construction;building dams and reservoirs;improving infrastructure.Reducing social vulnerability by strengthening flood management: prepare drill plans;improve emergency response systems;improve emergency response mechanisms;improve legal systems.47 figures,5 tables,and 112 references.