After the Wenchuan earthquake, a large number of landslides in debris flow basins continued to provide loose debris for channels and further affected the occurrence of debris flows. Evaluating the landslide sediment supply capacity in debris flow basins requires understanding the landslide activity and the coupled relationship between the landslide and the channel. In this study, we proposed a model based on the landslide area density index (P_Als) and the landslide connectivity (IC_l) to evaluate the capacity of the landslide sediment supply for channels in 46 sub-catchments in the study area. The capacity of the landslide sediment supply for channels generally decreased from 2008 to 2018, but due to the influence of heavy rainfall, the actual capacity of the landslide sediment supply for channels in the study area may gradually diminish in an unstable way, and it may arrive at the pre-earthquake level by 2025 without the influence of extreme rainfall. However, higher debris flow activity may last longer than 2025 because sufficient gully materials are still accumulated in the channel. The sediment transport capacity of landslides was divided into five levels: extremely, high, moderate, slight and low. The capacity of the landslide sediment supply for channels changed from extreme levels and high levels to moderate levels and slight levels after the first 5 years of the Wenchuan earthquake and was then dominated by low levels. Simultaneously, the regions with higher landslide sediment supply capacities gradually changed from along the Minjiang River regions to the upper and middle reaches of the debris flow basin from 2008 to 2018. Hongchun gully, which is in the study area, was chosen as an example to compare the assessment results and field investigation. The long-term evolution of landslides is an important reason for the decrease in the sediment supply capacity of landslides.

汶川地震发生后，泥石流盆地内大量滑坡继续为河道提供疏松碎屑，进一步影响了泥石流的发生。要评估泥石流盆地中的滑坡沉积物供应能力，需要了解滑坡活动以及滑坡与河道之间的耦合关系。在这项研究中，我们提出了一个基于滑坡面积密度指数（P _Als）和滑坡连通性（IC _l），以评估研究区域46个子汇水区的河道滑坡沉积物供应能力。2008年至2018年，河道滑坡沉积物供应量总体上有所下降，但由于暴雨的影响，研究区河道滑坡沉积物实际供应量可能以不稳定的方式逐渐减少，可能到2025年达到地震前的水平，而不受极端降雨的影响。但是，更高的泥石流活动可能会比2025年持续更长的时间，因为通道中仍然积聚了足够的沟壑物质。滑坡的输沙能力分为五个等级：极高，高，中，轻和低。汶川地震发生后的头五年，滑坡沉积物的输水能力从极端水平和高水平改变为中等水平和轻微水平，然后以低水平为主。同时，从2008年到2018年，滑坡含沙量较高的地区从along江地区向泥石流盆地的中上游逐渐变化。比较评估结果和现场调查。滑坡的长期演化是滑坡沉积物供应能力下降的重要原因。从2008年到2018年，滑坡含沙量较高的地区从沿along江地区到泥石流盆地的中上游逐渐变化。以研究区的红春沟为例进行比较。评估结果和现场调查。滑坡的长期演化是滑坡沉积物供应能力下降的重要原因。从2008年到2018年，滑坡含沙量较高的地区从沿along江地区到泥石流盆地的中上游逐渐变化。以研究区的红春沟为例进行比较。评估结果和现场调查。滑坡的长期演化是滑坡沉积物供应能力下降的重要原因。