| Drought disasters is one of the types of most influential natural disasters in the world,which cause the largest agricultural losses.With the significant change in global climate and the growing demand for water resources,drought risk in China's agricultural system is increasing.Henan province is the core area of China's grain production,the grain yield is directly related to the food security situation China.Therefore,it is necessary to strengthen the research of agricultural drought risk in Henan Province,as the agricultural drought disaster in China and the development of scientific management and provide theoretical support for the disaster prevention and mitigation strategies.The in Henan Province as the research object,on the basis of comprehensive analysis of natural disaster risk and agricultural drought disaster risk research status and development trend of,natural disaster risk analysis theory applied to the agricultural drought disaster risk analysis,put forward a kind of based on disaster system theory of agricultural drought disaster risk analysis method,and use the method of Henan Province agricultural drought disaster risk analysis,evaluation,and achieved the following results and conclusions:(1)Through the carding and analysis of drought,drought,agricultural drought risk concept,the formation of the basic cognition on agricultural drought risk.At the same time,we find,agricultural drought is one of the important types of natural disasters,in addition to using traditional drought risk analysis method to study,can also use the natural disaster system theory to the research of;combined with the concept and characteristics of agricultural drought,further disaster system theory is applied to the risk assessment of agricultural drought in proposed a analysis method based on disaster system theory of agricultural drought risk.The method of agricultural drought risk is drought induced hazard formative factors and disaster bearing body's vulnerability of the result of the interaction,induced disaster risk factors by bearing the vulnerability of hazard affected bodies of the conversion,and ultimately the formation of agricultural drought risk.(2)According to the agricultural drought disaster risk assessment method system,the run theory and copula multidimensional joint distribution theory to analyze the risk of agricultural drought in Henan Province,the drought frequency analysis.Firstly,according to the theory of run,this paper selects SPI drought index,the selection of drought duration and intensity of drought drought variables to identify drought;secondly,determine the drought variables subject to the optimal distribution;then according to the fitting effect of different types of Copula function selected drought duration and intensity of the two-dimension joint distribution;according to the results of the joint probability distribution,the co-occurrence not exceeding probability as the drought risk index,thus obtains the Henan province 18 regional agricultural drought risk of distribution.(3)According to the theory of disaster system.Analysis of agricultural drought vulnerability factors,sensitivity,exposure,drought resistant ability and establishing the corresponding evaluation index system;the use of variable fuzzy set theory,by combination weighting method,construction of agricultural drought disaster vulnerability evaluation model;using the model of 18 cities of Henan Province in 2011 agricultural drought vulnerability evaluation calculation,results show that: Agricultural Drought in Henan Province fragile overall presentation to grade III,the central region vulnerable lower,southern fragile high.(4)Under the “ R(risk)= H(risk)* V(vulnerability)” thinking,the idea of constructing agricultural drought risk assessment model,and the assessment of the risk of agricultural drought in 2011 in Henan province.By comparing the calculated results with the grain yield of Henan Province in 2011,the rationality of the risk assessment results is further verified.Based on disaster system theory of agricultural drought disaster risk analysis method can not only calculate the regional agricultural drought risk,but also can reflect the hazard bearing body in the disaster in the process of development,so as to provide technical support for the agricultural drought disaster risk management and control. |
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