The Distribution Characteristics of Large Landslides Along the Daduhe River in the Eastern Tibetan Plateau and Their Effects on Landscape Evolution

Landslides play a crucial role in landscape evolution, particularly in tectonically active areas. However, research on the relationship between landslide development and landscape evolution remains limited. This study examines the hypsometric integral (HI) values of the Daduhe river mainstem catchments to assess the landscape evolution stage and investigate its spatial correlation with the occurrence of landslides. Additionally, it evaluates the distribution of large landslides concerning elevation and slope. Furthermore, by analyzing the longitudinal profile of the Daduhe river, this study explores the relationship between the occurrence of landslides and knickpoints, as well as the impact of landslides on catchment morphology and material redistribution. The results show that the HI values of catchments along the Daduhe river range from 0.35 to 0.71, exhibiting a progression from youth to maturity and monadnock stages from upstream to downstream. Large landslides were predominantly distributed in areas with elevations of 1000–2000 m and slopes < 40°. Their distribution was closely linked to HI values: large landslides were sparse in catchments with HI > 0.5 (Banma county to Danba county) but more frequent in catchments with HI < 0.5 (Danba county to the river outlet). The longitudinal profile of the Daduhe river illustrates variations in channel morphology, with large landslides entering the river and facilitating the formation of knickpoints. The impact of large landslides on catchment landscape transformation, both in terms of morphology and material movement, exhibits a trend of gradual intensification from upstream to downstream. This study shows that landscape evolution can provide rich information to locate regions prone to landslides.