新疆北部雪灾气候因子的风险分析试验——以阿勒泰为例

用新疆北部阿勒泰站1954—2010年资料,分析致灾大雪5个气候因子的概率风险。在模糊信息扩散理论初步分析的基础上,进行综合分析试验。试验表明,在未知理论分布的情况下,模糊信息扩散法对雪灾气候因子的概率风险分析可靠简便,缺点粗糙。进一步的理论分布分析,发现冬季大雪(≥6mm)日数、最大雪深、日最大降雪量、冬季降雪量、大于等于10cm雪深日数的理论分布模型,具有Gamma分布特征,通过α=0.001的相关系数显著性检验。分析不同界限雪深日数的气候因素族的概率密度分布,发现其具有双峰型特征,不属于常规典型分布,其理论分布有待深入研究。提出的Gamma分布,分析计算的步骤、方法有实际应用价值。试验确定的具有Gamma分布特征的几个雪灾气候因子,对于从理论上认识雪灾气候风险具有重要意义。

Analysis Test of Northern Xinjiang Snow Climate Risk:Taking Aletai as an Example

By means of the observation data from the Aletai station of the northern Xinjiang from 1954to 2010,the probabilistic risk analysis for snow disasters is conducted for five major climate factors,and based on the fuzzy information diffusion theory,a comprehensive analysis experiment is carried out.The results show that in the case of unknown theoretical distribution,for the probability risk analysis of snow climate factors,the fuzzy information diffusion method is simple and reliable,but rough.The theoretical analysis of distribution indicates that the theoretical models of the number of heavy snow days in winter（≥6mm）,maximum snow depth,maximum daily snowfall,snowfall in winter,and the number of snow days with snowfall greater than or equal to 10cm have the distribution characteristics of Gamma,with a confidence degree of 0.001,passing through the test of significant correlation coefficient.The probability density distributions of climate factors are analyzed for the numbers of the days with different boundary snow depths.The results exhibit the two-peak characteristic,which does not belong to the conventional canonical distribution,and the theoretical distribution needs further study.The proposed snow climate factors with gamma distribution are of significance for understanding the climate risk of snow disasters in theory.