Geomorphic effect of landslide dam on the Jinsha River

As an extreme surface process, landslide dam affects the long-term change of river landform, especially the change of channel and hillslope. The Jinsha River is located on the eastern edge of the Qinghai-Tibet Plateau, the structural geology is active, developed more landslide geological disaster. Based on the 30 m SRTM DEM, we automatically extracted the river longitudinal profile, steepness index, river knickpoint and excess topography using TopoToolbox. Through interpretation of remote sensing imagery and field work, we identified 660 landslide dams, more than 90% are located in the excess topography with a threshold hillslope of 30. Our analysis reveals that there are 481 river knickpoints were extracted with heights above 30 m, Among them, 70 river knickpoints have good spatial correlation with the landslide dam, landslide dam has an impact can form knickpoints of up to 478m. In the densely distributed river channel of the landslide dam, the steepness index with the relatively high values. Therefore, landslide dams may have a significant inf1uence on the channel and hillslope, we should pay attention to the role of landslide dam in the evolution of river landscape.