Cover Story：UAV (Unmanned Aerial Vehicle) image of “3.24” landslide that happened along Piliqing River in Yin-ing County, Xinjiang. In recent decades, the global warming has led to the frequent occurrence of such geohazards as rock collapse, landslide and debris flow in the permafrost areas and seasonal frozen ground areas. The Yili River valley lies in the western segment of the Tianshan Mountains and belongs to a typical seasonal frozen ground area. The freeze-thaw loess landslide is characterized by shallow, multi-phase and progressive sliding. Based on detailed field investigation, dynamic comparison of multi-phase remote-sensing images and numerical simulation, the authors studied the freeze-thaw instability mechanism and movement characteristics of the loess landslide. And the results show that the increase of pore water pressure resulting from the uprising of the groundwater level is the major reason responsible for the landslide freeze-thaw instability. This research achievement has provided a good example and technical support for the early identification and risk assessment of the same type landslide. For details, see pp. 339-349 of this issue. (Photo by ZHU Sai-nan)