摘要：Landslides are major hazards that may pose seriousthreats to mountain communities. Even landslides in remote mountains couldhave non-negligible impacts on populous regions by blocking large rivers andforming dam-breached mega floods. Usually, there are slope deformationsbefore major landslides occur, and detecting precursors such as slopemovement before major landslides is important for preventing possibledisasters. In this work, we applied multi-temporal optical remote sensingimages (Landsat 7 and Sentinel-2) and an image correlation method to detectsubpixel slope deformations of a slope near the town of Mindu in the TibetAutonomous Region. This slope is located on the right bank of the JinshaRiver, ∼80 km downstream from the famous Baige landslide. We used aDEM-derived aspect to restrain background noise in image correlationresults. We found the slope remained stable from November 2015 to November2018 and moved significantly from November 2018. We used more data toanalyse slope movement in 2019 and found retrogressive slope movements withincreasingly large deformations near the riverbank. We also analysedspatial–temporal patterns of the slope deformation from October 2018 toFebruary 2020 and found seasonal variations in slope deformations. Only thefoot of the slope moved in dry seasons, whereas the entire slope was activatedin rainy seasons. Until 24 August 2019, the size of the slope withdisplacements larger than 3 m was similar to that of the Baige landslide.However, the river width at the foot of this slope is much narrower than theriver width at the foot of the Baige landslide. We speculate it may continueto slide down and threaten the Jinsha River. Further modelling works shouldbe carried out to check if the imminent landslide could dam the Jinsha River andmeasures should be taken to mitigate possible dam breach flood disasters. Thiswork illustrates the potential of using optical remote sensing to monitorslope deformations over remote mountain regions.
