基于信息扩散方法的秦岭北麓汛期暴雨洪涝灾害风险评估

为了科学支撑秦岭北麓休闲旅游区的防灾减灾工作,利用秦岭北麓22个测站1976—2010年汛期(5—10月)的逐日降水资料资料,采用距平分析、Mann-Kendall检验以及基于信息扩散的模糊数学方法对秦岭北麓汛期暴雨洪涝进行了气候变化特征分析及灾害风险评估。结果表明:秦岭北麓各站汛期降水及暴雨频次地区差异很大,均呈南多北少分布,大值中心位于陕南中南部地区;1980—1989年为秦岭北麓汛期降水及暴雨频次偏多期,1990—1999年为偏少期,进入2000年以来较1990—1999年有明显增长,汛期区域降水及暴雨总数分别在1989年及1991年出现突变性下降;随着暴雨及洪涝风险水平的增加,灾害出现的概率随之减小,汛期秦岭北麓遭受洪涝及暴雨灾害的风险从北向南逐渐增加,灾害风险高值区主要位于汉中北部及安康西部地区。

Risk Assessment of Rainstorm and Flood Disasters in Flood Season in the Northern Foot of Qingling Mountain Based on Information Diffusion Method

In order to scienticly support the disaster prevention and reduction work in leisure tourism area of northern foot of Qingling Mountain, using the data of daily precipitation including 22 meteorological stations in flood season (from May to October) during 1976-2010 in the northern foot of Qingling Mountain, the changing climate characteristics and the risk of rainstorm and flood disasters in flood season were analyzed by the methods of anomaly analysis, Mann-Kendall test and information diffusion theory. Results showed that regional precipitation and rainstorm frequency of the northern foot of Qingling Mountain in flood season had obvious geographical differents, which decrease from south to north by both, and the high value center of regional precipitation and rainstorm frequency all located in central and south of southern Shaanxi; The regional precipitation and rainstorm frequency of the northern foot of Qingling Mountain in flood season increased during 1980-1989 firstly, decreased significantly during 1990-1999, grew again since entering the new century, and appeared an abrupt decline in 1989 and 1991 respectively; With the increasing of risk level, the probability of occurrence of rainstorm and flood disasters appeared to decrease. The risk of rainstorm and flood disasters in the northern foot of Qingling Mountain in flood season showed a increasing trend form north to south. The north of Hanzhong and the west of Ankang were the high value area of disaster risk.