云南降雨型滑坡县级预警雨量阈值分析

根据云南省华坪县滑坡灾害历史数据和同期气象站实测小时降雨资料，以滇西北的华坪县为例动态地计算了每次滑坡灾害的有效降雨天数和对应前期的有效降雨量；并应用主成分分析法对44场降雨型滑坡进行分析，结果表明间接前期雨量、发生雨量和激发雨量对诱发滑坡都有重要影响，得出诱发滑坡的降水有短时强降雨和长时低强度降雨两种类型。由此建立了含有两类降雨特点的华坪县I〖CD*2〗D（降雨强度〖CD*2〗历时）阈值曲线，并在此过程中提出了确定降雨历时D结束时刻的方法和有待进一步研究的问题。通过对华坪县滑坡预警雨量研究，为其他县级滑坡灾害预警雨量阈值的确定提供一种方法。

County Level Rainfall Warning Thresholds for Rainfall Induced Landslides in Yunnan

By means of the historical landslide hazards data and the corresponding hourly precipitation, taking Huaping Station of Yunnan Province as an example, the effective rainfall days and the corresponding antecedent precipitation are calculated. The method of principal components analysis is applied to study the impact of the rainfall factors on the occurrence of landslides in order to understand the contribution of antecedent precipitation. The results show that the antecedent precipitation, occurrence precipitation, and excitation precipitation are important for the occurrence of landslides. The weighted relation between antecedent precipitation and occurrence precipitation is discussed. The landslide induced rainfall includes short term heavy rainfall and prolonged low intensity rainfall. The relation of rainfall intensity to duration thresholds, which contains two types of rainfall characteristics, is obtained for the initiation of landslides at Huaping. A method for defining the end point of rainfall duration and issues needing further study are discussed. The findings about warning rainfall thresholds for Huaping Station can be used as a reference for determining warning rainfall thresholds for landslide disasters.