First World Congress of International Consortium on Geo-disaster Reduction (1st ICGdR World Congress)

Large landslide cascades can trigger long-term geomorphic adjustment, yet post-event topographic changes remain difficult to observe in high mountain valleys. This study reconstructs multi-temporal TanDEM-X DEMs from 2011 to 2023 and uses them to estimate multi-year linear elevation-change rates after the 2000 Yigong landslide cascade. The workflow combines coherence and radar-geometry screening, effective observation counts, bias correction using stable reference areas, and land-cover-based interpretation using ESA WorldCover data. A total of 36 candidate elevation-change patches were identified, covering approximately 0.052 km². These patches include snow and ice surface changes, deposit-related lowering and thickening, and tree-cover surface signals. Surface lowering in snow- and ice-covered terrain was the dominant signal by area, with a median elevation-change rate of approximately -2.21 m/yr. The results indicate that the reconstructed multi-temporal TanDEM-X DEMs provide useful spatial evidence for analyzing post-landslide topographic evolution and locating possible instability or deposit-adjustment areas in complex mountain environments.

TanDEM-X,multi-temporal DEM,landslide cascade,high mountain terrain,Himalaya