Landslides are a major natural hazard and act as a primary driver of erosion, chemical weathering and organic carbon transfer in mountain ranges. Evaluating the impact of landslides on Earth systems requires knowledge about the controls on their size, which are not well understood. Here we show that topographic stress, resulting from the interaction between tectonic stress and topography, influences bedrock landslide size at landscape scales by modulating the subsurface material strength through fracturing and weathering. Using a three-dimensional topographic stress model, we characterize the spatial pattern of subsurface open-fracture zones in a crystalline-rock terrain of the eastern Tibetan mountains. Then, we compare the predicted open-fracture zones with 982 mapped bedrock landslides. The results show that areas with deeper subsurface open-fracture zones tend to accommodate larger landslides. This is probably due to the influences of topographically induced fractures on the material strength and groundwater flow paths and rates. We conclude that the extent of hillslope failure depends on both distant tectonic forces and local topography, which has implications for hazard mitigation, landscape evolution and the global carbon cycle.

滑坡是主要的自然灾害，是山脉侵蚀、化学风化和有机碳转移的主要驱动因素。评估滑坡对地球系统的影响需要了解对其规模的控制，而这些知识还不是很清楚。在这里，我们展示了由构造应力和地形之间的相互作用产生的地形应力通过压裂和风化调节地下物质强度来影响景观尺度的基岩滑坡尺寸。使用三维地形应力模型，我们描述了藏东山区结晶岩地形中地下开放断裂带的空间格局。然后，我们将预测的开放断裂带与 982 个映射的基岩滑坡进行比较。结果表明，具有较深地下开放断裂带的区域倾向于容纳较大的滑坡。这可能是由于地形诱发的裂缝对材料强度和地下水流动路径和速率的影响。我们得出结论，山坡破坏的程度取决于遥远的构造力和当地地形，这对减灾、景观演变和全球碳循环都有影响。