基于信息扩散理论的甘肃省农业旱灾风险分析

Risk Assessment of Agriculture Drought Disaster in Gansu Province Based on Information Diffusion Principle

干旱灾害是甘肃省最严重的自然灾害。以甘肃省1990～2010年的干旱受灾面积和播种面积的统计数据为基础,采用基于信息扩散理论的模糊数学方法,建立甘肃省农业旱灾风险分析模型,对甘肃省农业旱灾进行分析。结果表明,甘肃省旱灾受灾指数在22%时的旱灾受灾概率最大,超过80%的旱灾受灾可能性就很小;旱灾风险值显示,农业旱灾受灾指数>10%～20%时的风险概率为1～1.6 a一遇,农业旱灾受灾指数>50%时的风险概率为12.2 a一遇,呈现出干旱发生周期短、发生频率高的特点,这说明甘肃省的农业旱灾出现频率高,发生周期短,灾情不容忽视。研究结果增加了对甘肃省农业旱灾的认识,对地区防灾减灾工作具有指导意义。

Drought disaster is the worst natural disaster in Gansu Province.A risk model of agricultural drought disaster was established based on statistical data of drought disaster area and planting area in Gansu Province during 1990-2010 by using the fuzzy mathematical method,and the agriculture drought disaster in Gansu Province was analyzed.The results show that the damage probability of drought disaster in Gansu Provinve reached maximum when the drought disaster index was 22% and it tended to be very low when the index exceeded 80%.The drought risk value showed that when the drought disaster index ranged from 10% to 20%,the drought occurred every 1-1.6 year in average,and if the index was over 50%,it happened every 12.2 years in average.Such probability distribution showed that the agricultural drought disasters in Gansu Province presented a high frequency and a short cycle,and the damage of disasters should not be overlooked.Better understanding of the current situation of agricultural drought disasters in Gansu Province by this study will be important to the prevention and mitigation of regional drought disaster.