关键词: 可蚀性系数, 河流剪切力, 侵蚀速率, 龙门山断裂带

Abstract: As one of the main geomorphic units, rivers records rich information after experiencing tectonic activity, climate change and sea level change. Based on the shear stress model, the fluvial erosion can be combined with the relevant parameters of the river, so that we can use the geomorphological parameters to calculate fluvial erosion rate. Based on the empirical relationship between fluvial shear stress and erosion rates of sedimentary rocks and granites in the Longmen Shan area, we calculate the erosion rate for 139 survey points of fluvial shear stress. In addition, according to the linear relationship between river erosion rate and fluvial shear stress, Erodibility coefficients of each survey point were calculated. The results show that the average erosion rate is 0.43 mm/yr in the footwall of Wenchuan-Maoxian fault, the average erosion rate in the hanging wall and footwall of Shuangshi-Dachuan fault is 0.49 mm/yr and 0.28 mm/yr, respectively. In addition, this study reveals that: (1) In the same lithology, the erodibility coefficient of bedrock near the fault is obviously larger than that of other regions, in other words, the rocks near the fault are more broken. (2) Sedimentary rocks are more severely affected by fault activities than granite, but the impact of sedimentary rocks is more concentrated.

Key words: Erodibility, Fluvial shear stress, Erosion rate, Longmen Shan