Assessment of Risks of Agricultural Drought Disasters in Henan Province Based on the Information Diffusion Theory
基于信息扩散理论的河南省农业旱灾风险评估

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.