280 / 2023-10-08 16:25:32

Identifying land disturbance caused by surface coal mining in China and land reclamation strategy

Surface mining; Remote sensing; Land use; China; Time series

Surface mining has, however, been subject to increased criticism and pressure due to its potential

to cause environmental damage. China accounts for more than half of world coal consumption, and this continued demand for coal, combined with low costs, has accelerated open-pit coal mining throughout the world. However, it is difficult to understand the true impact of surface mining in China. Therefore, we constructed an Exposed Coal Frequency Index (ECFI) in the absence of any coal mining information and narrowed the study scope by crawling POI data to identify the entire mining sites within China. A LandTrendr algorithm was used to reconstruct past mining disturbances and reclamation events (1986-2021). While examining these events, the key information was analyzed in order to reveal the true impact of surface coal mining on vegetation in China. Based on the results, (1) the detection accuracy of statistical open-pit mining sites by province reaches 91.8%, while the detection accuracy of disturbance, as well as reclamation events, exceeds 72.59 %. Also, by comparing the mine data, our results provide more accurate disturbance information in terms of both time and spatial consistency. (2) A total of 253.61 km² of open-pit mining sites were identified in 14 provinces or autonomous regions during the period 1986-2021. Of these, Inner Mongolia, Ningxia, Shanxi and Xinjiang ranked in the top four occupying 89.0% of the total mining site. (3) China has cumulatively disturbed 545.84 km2 and reclaimed 169.41 km2 including more comprehensive human activities. In the last 12 years, large-scale mining and reclamation have accounted for 51.63% and 75.17% of the cumulative area, respectively. (4) In general, reclamation in China can be completed within four years. In contrast, reclamation time intervals and the proportion of reclamation varied widely between mining areas. Clearly, this study provides the most accurate data on surface coal mine disturbances in China, which will be beneficial for future studies in spatial geography related to mining, also including more policies and management creation for mines.