Agricultural Drought Disaster Risk Assessment And Application Researc

With the rapid development of the global economy,human activities continue to produce greenhouse gases,leading to global warming,increasing the probability of extreme weather events.Climate change driven by human activities will increase the risk of drought.As a meteorological disaster with the highest frequency,the longest duration and the widest radiation range in the world,drought has caused the most losses to China’s agriculture.At the same time,China is a country with vast territory and great regional differences.Coupled with the impact of climate change,China has become one of the most common and seriously affected countries,the drought affected area and drought disaster loss of crops are the largest among all kinds of natural disasters.The impact of drought disaster on agricultural production is very serious,and even threatens the safety of China’s grain production,and this disaster risk still has a trend of sustainable development.As a large developing agricultural country,it is very important for China to control agricultural risks and ensure the stability of agricultural development.Therefore,it has raised the requirements for agricultural drought risk assessment.It is of great practical significance to conduct research on agricultural drought risk assessment methods and their applications.The research content of this paper is to take 13 major grain producing areas as research objects,according to China’s agricultural development and drought disasters.Select ten evaluation indexes from four aspects: the risk of disaster causing factors,the vulnerability of disaster pregnant environment,the exposure of disaster bearing bodies,and the ability of disaster prevention and reduction(post disaster recovery).On the basis of determining the index weight by using the entropy method,combined with the comprehensive evaluation method,the agricultural drought disaster risk indexes of 13 provinces are constructed respectively.The spatial and temporal variation characteristics of agricultural drought risk factors and agricultural drought risk indexes were compared and analyzed from the perspective of provinces and regions.Then,quantile regression was used to explore the relationship between agricultural drought disaster risk index and agricultural drought disaster situation under different drought degrees,especially the extreme quantile.Finally,based on the over threshold model,the over threshold part of the agricultural drought disaster risk index is fitted to the Generalized Pareto Distribution,and the value at risk and expected loss under different confidence levels are calculated.Through this series of calculation and analysis,the purpose of quantitative analysis and evaluation of agricultural drought risk index is realized,which provides a reference idea for future agricultural drought risk management.According to the index weights determined by the entropy method,the comparison results by provinces and regions show that the weights of each region under each evaluation index are different,and the uncertainty of each risk component in each region has its own characteristics,which can help to master the advantages and disadvantages of agricultural drought development in different regions while directly showing the regional differences.From the comprehensive comparison results of agricultural drought disaster risk index,the spatial and temporal characteristics of agricultural drought risk are extremely uncertain,but the constructed agricultural drought disaster risk index can accurately describe these drought events,and can objectively and clearly express the agricultural drought disaster risk faced by different provinces and regions through numerical values,these can directly or indirectly prove that the agricultural drought risk index constructed in this study has good expression effect and applicability.The conditional quantile regression results of the agricultural drought disaster risk index and the drought affected area of crops show that the regression results of the agricultural drought disaster risk index in 13 provinces are significant,and the regression coefficients are positive,indicating that the drought risk index has a positive effect on the drought affected area of each province,and can accurately describe the differences in agricultural drought risk at different levels,especially for extreme drought events.The peak over threshold model based on extreme value theory calculates the value at risk and expected shortfall of 13 provinces under different confidence levels.The comparison results by provinces show that the risk index of extreme agricultural drought events in Inner Mongolia,Hebei,Jiangxi,Heilongjiang,Jilin and Hubei is the highest in the future.The comparison results of sub regions show that the three regions will face the risk of extreme agricultural drought events in the future,from large to small,as the main producing areas of Songliao Basin,Yangtze River Basin and Huang Huai Hai Basin.In the future,the main producing areas of Songliao basin will face the greatest risk of extreme agricultural drought disasters,and four of them are relatively large grain producing provinces among the 13 main grain producing areas,this will bring great hidden dangers to the national food security.The main production areas in Songliao basin should become the key direction of agricultural drought disaster prevention and control in China.