基于信息扩散理论的河南省农业旱灾风险评估

Assessment of Risks of Agricultural Drought Disasters in Henan Province Based on the Information Diffusion Theory

粮食核心区建设是河南省建设中原经济区的核心战略之一,而气候变化背景下各种气象灾害的频繁发生对其提出了严峻的挑战,其中,旱灾是河南发生频率最高的自然灾害。采用基于信息扩散理论的风险评估模型对河南省自1971年以来的旱灾危害从致灾和承灾两个层面进行评估,从而给出不同程度旱灾发生的可能性,为河南省粮食核心区战略地位的提升及灾害防治提供理论依据。研究结果表明:从承灾层面来看,受灾风险等级远高于成灾风险等级;受(成)灾面积指数一般不超过50%和30%,该受(成)灾面积指数下的风险概率值分别达到0.001和0.0006;受(成)灾风险概率小于3年一遇的面积指数分别为25%和10%;5%、10%、15%、20%成灾面积指数下的风险估计值分别为0.76、0.39、0.16和0.10,即分别为1.3年、2.6年、6.1年和9.8年一遇;从致灾层面来看,偏旱的估计值为0.110,即约9年一遇,在此等级下,分别对应受(成)灾面积指数为35%和20%。评估结果与河南省农业气象旱灾发生的实际情况基本吻合,表明应用此模型对信息量不足的自然灾害进行风险性评估是科学可行的。

Construction of the grain core area is one of the core strategies of building the central economic region in Henan Province.However,a variety of meteorological disasters occur frequently,which impose big challenges to the construction of the grain core area.Drought is one of natural disasters with the highest frequency in Henan Province.This study evaluated drought disaster from two dimensions in Henan Province since 1971,i.e.,the disaster-produced and disaster-consequence.A risk evaluation model was employed based on information diffusion theory.The objectives of this study were to provide different degrees of drought occurrence probability,and a theoretical basis for disaster prevention for Henan Province＇s agricultural production and the promotion of a strategic position of the grain core area.On the one hand,from the perspective of disaster-consequence,the level of the disaster-affected risk was much higher than that of the disaster-formative risk.In general,the area index of the disaster-affected and disaster-formative aspects was less than 50%and 30%,respectively.The risk probability values were 0.001 and 0.0006.The area index of the disaster-affected and disaster-formative aspects were 25%and 10%,respectively,which were smaller than 3a occurrence.The risk estimates were 0.76, 0.39,0.16,and 0.10,respectively,to the disaster-formative area index of 5%,10%,15%,and 20%, i.e.,1.3a,2.6a,6.1a and 9.8a occurrence,respectively.On the other hand,if investigated from the disaster-produced perspective,the estimated value of the semiarid area was 0.110,equivalent to 9a occurrence.For this grade,the area index of the disaster-affected and disaster-formative aspects was 35%and 20%,respectively.Results of this study generally accord with the facts of agriculture meteorological drought disasters in Henan Province.The study showed that the risk evaluation model based on the information diffusion theory model was sounded and feasible to assessment of information content inadequacies of natural disaster risks.