Subsidence Characteristics in North Anhui Coal Mining Areas Using Space-Air-Ground Collaborative Observations

To fully comprehend the patterns of land and ecological damage caused by coal mining subsidence, and to scientifically carry out ecological mine restoration and management, it is urgent to accurately grasp the information of coal mining, particularly in complex coaling areas, such as North Anhui, China. In this paper, a space-air-ground collaborative monitoring system was constructed for coal mining areas based on multi-source remote sensing data and subsidence characteristics of coaling areas were investigated in North Anhui. It was found that from 2019 to 2022, 16 new coal mining subsidence areas were found in northern Anhui, with the total area increasing by 8.1%. In terms of land use, water areas were increased by 101.9 km² from 2012 to 2022, cultivated land was decreased by 99.3 km², and residence land was decreased by 11.8 km². The depth of land subsidence in the subsidence areas is divided into 307.9 km² of light subsidence areas with a subsidence depth of less than 500 mm; 161.8 km² of medium subsidence areas with a subsidence depth between 500 mm and 1500 mm; and 281.2 km² of heavy subsidence areas with a subsidence depth greater than 1500 mm. The total subsidence governance area is 191.2 km², accounting for 26.5% of the total subsidence area. From the perspective of prefecture-level cities, the governance rate reaches 51.3% in Huaibei, 10.1% in Huainan, and 13.6% in Fuyang. The total reclamation area is 68.8 km², accounting for 34.5% of the subsidence governance area. At present, 276.1 km² within the subsidence area has reached stable subsidence conditions, mainly distributed in the Huaibei mining area, which accounts for about 60% of the total stable subsidence area.