基于危险度区划的县级区域降雨引发滑坡的风险预警方法——以四川省米易县降雨滑坡为例

降雨滑坡预警在世界上开展广泛，但对小区域的降雨滑坡风险进行预警尚不多见。以通用的风险定义为基础，首先对目标区域——四川省米易县的地质灾害进行调查，以典型滑坡进行反演，获得灾害的本底因素，按贡献率权重叠加法进行危险度分区；通过对承灾体的调查确定承灾对象，并将各承灾对象按密度由行政界限向1km×1km的网格单元转化后叠加形成易损度分区。二者相乘完成风险分区。对研究区域近5年逐日降雨数据与172条地质灾害记录进行分析，按前期日降雨量模型得到降雨阈值，根据滑坡空间概率和降雨引发滑坡的时间概率叠加的结果，得到研究区域的降雨滑坡概率，对照风险分区，完成风险预警。

A method of early warning on rainfall-induced landslide risk probability based on hazard zoning: a case study on the rainfall-induced landslide of Miyi County, Sichuan, China

Rainfall-induced landslide early warning is broadly conducted in the world, but still little work has been done for small-scale risk. This paper starts from the common definition of risk, investigated the geo-hazard of Miyi County, Sichuan province, China. The first step is landslide zoning by contributing weight method after obtaining the main factors that cause landslide with inversion, then the second step is vulnerability zoning after analyzing the main disaster-bearing objects and convert their density from administrative regionalism to 1km×1km grid. After these two steps the risk zoning is achieved. The third step is get the rainfall threshold value according to daily rainfall modeling, by analyzing the relationship between daily precipitation in the past 5 years and 172 pieces of geo-hazard records. Trough overlaying landslide spatial probability with precipitation time probability, regional rainfall-induced landslide probability is obtained. Early warning work can be carried out with the help of risk zoning result.