基于临界水深法的单沟泥石流启动降雨量推算

Calculation of Starting Rainfall for Single Debris Flow Based on Critical Water Depth Method

以汶川县七盘沟为研究对象,在高精度遥感影像的支持下,通过对七盘沟的实地勘察,收集汇总了七盘沟泥石流的基础数据(松散堆积体属性、泥石流容重等)。应用临界水深法,结合七盘沟的实际情况,逆向推求七盘沟泥石流启动的临界降雨量。研究发现:汶川县七盘沟流域共查明117处松散堆积体,其临界水深介于0.18~11 m之间,松散堆积体的临界启动值为0.1~6.9 m/s,启动降雨量处于0.1~174 mm之间。本研究结果与七盘沟实际情况基本吻合,可为单沟泥石流监测和预警预报系统的建设和完善提供一定参数指导。

We take the Qipan gully in the upper reaches of Min River as an example. With the help of investigation report of Qipan gully and the interpretation of remote sensing image, the basic data of debris flow （loose accumulation position, debris flow density and so on） is collected. To combine with the actual situation, the starting rainfall of the single debris flow is calculated by the critical depth method. The result showed that： 117 loose accumulations have been identified in the Qipan gully basin. The critical depth of loose accumulation is between 0.18~11 m. The threshold value of loose accumulation is 0.1-6.9 m/s. The critical rainfall is between 0.1-174 mm. The research results will provide some help for the improvement of debris flow monitoring and warning system.