关键词: 地形因子, 群发性泥石流, 斜坡坡度, 流域面积, 纵比降, 都汶高速

Abstract: On July 10, 2013, different levels of debris flow disasters occurred in 32 gullies along the Duwen Expressway (Referred to as "7?10" disaster), causing the interruption of the Duwen Expressway and the blockage of the Minjiang River. Based on the “7?10” disaster, this paper used ArcGIS to extract the key topographic factors of debris flow gullies in the study area (such as the basin area A, the main gully channel length L, the longitudinal gradient J, and the gully slope S, etc.). Combined with the calculation model, the influence of topographic factors on the development of debris flow was analyzed. The result indicated that the occurrence of “7?10” cluster debris flow was consistent with a threshold model that we put forward. The larger the topographical factor G of the debris flow gully was, the better the topographic conditions in the debris flow gullies were, and debris flow was prone to occur when G>0.45. Therefore, the comprehensive topographic factor G was suggested to measure the susceptibility of debris flow. It can provide a scientific basis for the risk assessment and early warning of debris flow gullies along the Duwen Expressway.

Key words: topographic factor, mass debris flows, gradient of slope, basin area, longitudinal gradient, Duwen Expressway