Multi-Temporal Monitoring and Analysis for Alxa Left Banner Open-Pit Mining Area Collapse Based on Lutan-1 SAR Satellites

A collapse accident occurred in the Alxa left Banner open-pit mining area of Inner Mongolia on February 22, 2023, causing heavy casualties and property losses. Multi-temporal pre-collapse and post-collapse images were acquired by the Lutan-1 SAR satellites, which is the first group L-band SAR constellation in China. The subsidence information of pre-collapse and post-collapse were extracted and analyzed, which provides certain knowledge for post-disaster accident handling and emergency response. Due to the extensive mining activities, the topography of open-pit coal mine area generally changes obviously. TanDEM and Gaofen-7 DEM were employed for deformation monitoring. The results indicated that time-efficient DEM is necessary for open-pit mining area monitoring. At the same time, based on the subsidence information detected before the disaster with high spatial and temporal resolutions, combining with prior information and expert interpretation, it is potential to provide certain support for the early hidden danger identification.