Temporal and spatial evolution characteristics and driving forces of coal mining subsidence waterlogging area in typical overlapped area of coal-crop

Coal mining subsidence waterlogging is the main ecological damage characteristic in overlapped area of coal-crop with high underground water level, it is of great significance to study the temporal and spatial evolution characteristics and driving mechanism of mining subsidence waterlogging area for optimal allocation of water and soil resources and land reclamation in overlapped area of coal-crop. Aiming to reveal the temporal and spatial evolution characteristics and driving mechanism of the subsidence waterlogging area in the overlapped area of coal-crop, Yongcheng Mining Area, a typical overlapped area of coal-crop, is selected as the research area, and the functions of ArcGIS software such as mask extraction and attribute extraction are used to extract waterlogging distribution information using the 30 m resolution land cover data of China from 1990 to 2020 from Landsat images. The variation and spatial distribution of waterlogging area in Yongcheng Mining Area in different years are compared and analyzed, thus the long time series evolution characteristics of coal subsidence waterlogging area in Yongcheng Mining Area is revealed. Based on coal mining subsidence process, the coupling relationship between mining subsidence and groundwater level and surface waterlogging is discussed, and the driving mechanism of temporal and spatial evolution of coal subsidence waterlogging area in combination with factors such as coal mining, precipitation and groundwater level is analyzed. The results show that the water body area of Yongcheng Mining Area increased by 8.233 2 km² from 1990 to 2020, and the variation range is small during the period of 1990-2000, however, the mining subsidence accumulative effect appeared after 2000, and the average annual growth rates of 2000-2005 and 2010-2015 are 12.821 3% and 10.141 2%, respectively. The expansion part of the waterlogging area mainly distributes in the middle, southwest, southeast and east of Yongcheng Mining Area. Coal underground mining is the main driving force for the increase of waterlogging area, which determines the spatial distribution range and extension direction of waterlogging area in coal mining subsidence area. The groundwater level and rainfall affect the waterlogging area distribution range in the coal mining subsidence area to some extent. Geological structure and ecological restoration project promote the increase of waterlogging area in coal mining subsidence area. The long time series evolution characteristics and the analysis of driving factors of typical coal mining subsidence waterlogging area are comprehensively studied, which could provide scientific basis for the sustainable utilization of land resources and ecological restoration in the overlapped area of coal-crop with high underground water level.