Response of snowmelt-driven loess landslides to climate change in Ten- zan, north-west China

Abstract

In seasonally frozen regions, snowmelt-induced landslides are becoming a common geomorphological process. However, their failure mechanism are not yet well understood. This study focuses on the Zeketai River Basin in the Ili Basin of Ten-zan, China, and attempts to explain the deformation process and failure mechanism. The results revealed that the 242 loess landslides showed obvious season distribution and aspect differentiation. The landslide probability density-area distribution was well in line with the three-parameter inverse-gamma probability distribution. Long-term snowmelt infiltration and repeated soil freezing-thawing affected the slope surface and subsurface hydrothermal and mechanical equilibrium. The combined effect of static liquefaction of sliding surface and sliding liquefaction at slope toe was a hybrid mechanism for slope deformation and failure. On exposed landslide slope thicker snowpack and faster snowmelt contributed to persistent deformation of this landslide. In the future, climate warming would increase snowmelt-driven slope failures in seasonally frozen regions. More careful consideration and discussion regarding the thermal-hydraulic and mechanical processes and early warning of snowmelt-driven landslides should be strengthened.