泥石流启动的临界地表径流深度研究

Study on Critical Depth of Surface Runoff of Debris Flow Occurrence

暴雨过程形成的地表径流导致坡体表面和前缘松散物质向下输移,汇入沟道,演变成危害性较大的泥石流,因此,对于泥石流的启动机理和启动临界条件的研究十分必要.根据下渗曲线法,得出了地表径流深度、入渗率以及降雨强度的关系,并运用牛顿定律、水文学以及土力学等理论,建立了泥石流单颗粒启动、局部启动和整体启动的临界地表径流深度的求解模型,从而可推得临界降雨强度,此可为泥石流的泥石流预警提供了有用的理论基础.

The surface runoff caused by the rainstorm made the slope surface and the loose materials of the leading edge move downward,then they were concentrated in steep channels to evolve into the larger harmful debris flow.Therefore,studying on the infiltration mechanism and the critical conditions of debris flow occurrence is necessary.According to the infiltration property curve method,this paper obtains the relationship among the depth of surface runoff,the infiltration rate and the rainfall intensity.By using the Newton law,hydrology and soil mechanics theory,this paper establishes an initiation model of the critical surface runoff depth of debris flow.It is related to three grades of soil particle initiation process.They are individual,partial,and whole grades.The critical rainfall intensity is obtained,which provides the useful theoretical basis for early warning of debris flow.