Study On Risk Assessment Of Agricultural Drought Disaster In Huaihe River Basin

Drought is the major natural disaster in the world that continually troubles the life ofpeople and the development of the economic, bring huge economic losses to differentcountries and districts every year, seriously restricting the sustainable development of thenational economy all over the world. Huaihe River Basin is an important commodity grainproduction base in China. However, on account of specific climatic conditions,geographical environment, basin characteristivs and human activities, there is a growingtrend on drought frequency and consequent losses, which are serious threats to nationalfood security. It is of great significance for improving the comprehensive ability of droughtcontrolling and drought mitigating of Huaihe River Basin and guaranteeing food securityand promoting sustainable development of drainage basins economy and society tosystematically assess Huaihe River Basin agricultural drought risk. Because agriculturaldrought is a kind of gradual onset disasters, affecting by natural systems, social systems,economic systems and their combinations, it is a complex system with certain structure andfunction. Agricultural drought risk analysis is mainly about the instability of pregnantdisaster environment, the danger of hazard factors, the exposure and sensitivity ofhazard-affected bodies, and the disaster prevention and mitigation capacity of drought area.Drought risk consists of these risk factors and their mutual interactions. Because ofuncertainty of hazard factors and complexity of environment, agricultural drought risksystem is full of a large number of various types of uncertainties. Therefore, how tocorrectly select the risk factors to establish models to quantitatively describe the extent ofdrought, and how to effectively identify and describe the uncertainty of drought riskassessment are the major problems. This paper chooses the Huaihe River Basin as thebackground, starting from the cause of drought, analysis the response rule of droughtaffected body, based on these studies to establish the assessment indexes system and modelof agricultural drought risk in Huaihe River Basin, then takes the Anhui province forexample, evaluates the agricultural drought risk in this region. Main results obtained are asfollows:(1)From the probability of occurrence, the spatial and temporal distribution and evolution law, analyzing the agricultural drought characteristics of Huaihe River Basin.From the natural factors and social factors, analyzing the formation of mechanism ofagricultural drought will come to the main reason for the formation of Huaihe Riverdrought.(2)According to the experimental data about the drought losses, preliminary analyzingthe cut law affected by drought of the main crops, including the impact of water deficit oncrop growth and yield. Quantitatively analyzing the sensitivity to water deficit of the maincrops at different growth stages.(3)Dividing the general Integrated drought Risk system into the hazardous subsystems,the exposure subsystem, vulnerability subsystem and drought resistance subsystems, whichwill establish the integrated risk assessment to the initial agricultural drought index system;using the results of the consultation of experts to establish the genetic fuzzy AHP based onthe evaluation index screening model, Screening and evaluating the index system, so thatcould establish the index system of the Huaihe River agricultural drought risk assessmentsystem; based on existing research results, combined with the actual situation of HuaiheRiver, by the standards of evaluation grades for each of the indicators into1level(micro-risk) and2level (weak risk),3level (middle risk) and4level (high risk)4level ofrisk in order to build risk assessment model of agricultural drought of Huaihe River.(4)Determining the index and the subsystems weights, to establish comprehensive riskassessment model based on the analysis of the agricultural drought; taking the Huaihe RiverBasin as a typical region, evaluating the agricultural drought risk assessment of the9rigions, and separately from the4subsystems as the hazard, exposure, vulnerability, anddrought resistance, to analyze the risk rating different districts; Having the four risksubsystems composite weighted, obtained the Huaihe River Basin agricultural drought riskassessment results: Suzhou are at high risk; Huaibei, Bozhou, Bengbu and Fuyang are atmiddle risk; Huainan, HeFei River Basin and Chuzhou River Basin are at weak risk, LuanHuai River Basin are at micro risk.