四川省九龙县暴雨诱发泥石流的时空特征及其阈值确定

Spatial-temporal Characteristics and Threshold Determination for Rainfall-induced Debris Flows in Jiulong County,Sichuan Province

暴雨是诱发四川省九龙县泥石流灾害的主要因素,本研究对九龙县气象局1952-2018年的气象数据和1991-2018年的泥石流灾害数据进行分析.结果表明:九龙县暴雨诱发泥石流具有明显的时空特征,九龙县境内各地均有发生泥石流灾害的可能性,发生概率由北向南依次增加,九龙县南部是泥石流的高发区;20:00-02:00是泥石流发生的高发时段.依据各种资料建立九龙县暴雨诱发泥石流预警指标体系:当降水强度大于16~20 mm/h时诱发泥石流的可能性较大,为注意级;降水强度在20~35mm/h时诱发泥石流的可能性很大,为预警级;降水强度≥35 mm//h时诱发泥石流的可能性极大,为警报级.

Rainstorm is the main factor that induces debris flow disaster in Jiulong County,Sichuan province. The Jiulong county rainstorm prediction and early warning index system was established. We analyzde the meteorological data from 1952 to 2018 and debris flow disaster data from 1991 to 2018 from Meteorological Bureau of Jiulong County. The results indicated that rainfall-induced debris flows has obvious spatio-temporal characteristics,there is the possibility of debris flow disaster in Jiulong,and it increases from north to south( easy occurrence area). Debris flow can be induced when the precipitation intensity is greater than 16 mm/h,and the precipitation intensity greater than 20 mm/h is the warning level. 02: 00-05: 00 and 20: 00-02: 00 are the periods of high occurrence of debris flow.