Land subsidence monitoring in coal mining collapse area of Urumqi

The Jurassic coal-bearing layers in Urumqi intersect the major metropolitan region in a near east-west direction, with the geological features of many coal-bearing seams and massive and virtually vertical single coal seams. For decades, coal resource mining has harmed Urumqi’s urban environment, and the ensuing subsidence zones endanger the productivity and lives of the surrounding population, as well as severely limiting the city’s development of the cities and the development and usage of land resources. The main data source in this paper is Sentinel-1A data from the Liudaowan coal mine and Reed Huliang coal mine, which straddle Shuimoegou and Midong districts in Urumqi, and SBAS-InSAR technique is used to monitor the surface subsidence phenomena of historical abandoned coal mines, existing mined coal mines, and surrounding residential areas in the study area from June 2018 to the end of June 2022. The SBAS-InSAR technology is used to process SAR data, obtain surface time series deformation results in the study area, and generate annual average rate and cumulative deformation variables after geocoding, and it is discovered that the extent of subsidence funnels in several mining areas expanded and the cumulative subsidence in the center of the subsidence funnels exceeded −150 mm. The total sinking of GPS and SBAS findings is determined after comparison with the results of the GPS. The trend is stable, and the root mean square error is less than 2-3 mm.