Risks Assessment Of Drought Disater In Hunan Province Based On The Information Diffusion Theory

Drought is one of the major natural disasters and also causes great losses in Hunan Province.In the background of global warming, drought occurred frequently and showed a tendency to increase during 21st Century.Evaluating the risk of drought is an important approach to understand drought occurrence regularity and take measures to deal with drought.Therefore,risk of drought in Hunan Province is assessed from two aspects including the disaster dangerousness and hazard bearing body’s vulnerability by using information diffusion model,which is based on the annual precipitation data and disaster statistical data from 2000 to 2013 in Hunan Province.After a review of the relevant drought literature of Hunan Province, the reasons of drought is analyzed systematically from four aspects including meteorological climate, crops, topography and socio-economic. And drought characteristics is summarized:drought occurs frequency and causes great losses; seasonal drought is the main actor and summer-drought and autumn-drought is the most severe drought; drought disaster has large regional differences; drought types is diversification.Based on the percentage of Precipitation Amomaly of spring,summer,autumn and winter in Hunan Province,information diffusion model was used to analyze probability value of four types of drought occurred under different risk levels and the results showed that: at the same dangerousness levels, the overall trend of drought affecting in Hunan is that risk of summer-drought and autumn-drought is greatest, followed by spring-drought’s and winter-drought’s is minimum. And, the drought hazard estimates is also calculated under different types of drought grade. It shows that four kind of drought have greatest risk on the partial drought grade and have minimum risk on severe drought grade through horizontal comparison drawn; risk of summer-drought and autumn-drought is greatest and winter-drought’s is minimum on the same grade of drought by longitudinal comparison drawn.This is consistent with the actual situation.Information diffusion model is applied to assessed the risk of hazard bearing body’s vulnerability,which chooses drought affected index and drought disaster index as evaluation index on the basis of data of drought disaster in Hunan Province.And the result proves that the drought which affected the area is more than 10% happen about every 1.57 a and the drought whose affected area is more than 20% occur about every 3.4 a;the drought whose affected area is more than half of the total acreage almost never happened.That is to say,drought almost occurs every year and just has different degree in Hunan ProvinceDrought disaster risk assessment is not only an important way to master the law of drought occurrence, but also is the important basis for the development of drought preparedness plan.Based on this, then combined with current situation of drought management in Hunan Province, drought avoidance strategy is made to cope with drought disaster initiatively...