第八届青年地学论坛

Mineral resource development is necessary for economic growth, but its negative impacts on land, ecology and the environment are significant and cannot be ignored. Identification the mine land disturbance process in a large regional scale is challenging without specific mining location information. Besides, how to quantitatively evaluates the ecological restoration effects became important for management and supervision, and reclamation strategy adjustment. Here, we propose a systematic workflow that utilizes Sentinel-2 images and other freely accessible remote sensing data products to identify and assess large-scale surface mining areas' restoration status and ecological quality without prior knowledge of mine locations, and implemented in Yangtze River region, the largest watershed area in China. The proposed process includes: (1) extracting surface mining areas using masking, morphological operations, and visual interpretation techniques; (2) constructing time series of Bare Surface Percentage (BSP) for each mining area on the Google Earth Engine (GEE) platform to distinguish between abandoned and active mines and examine their restoration rates; (3) constructing the Remote sensing Ecological indicator for Mining areas (REM) to quantify ecological quality and its temporal changes. The results show that: (1) the proposed method effectively identifies surface mining areas with higher boundary delineation accuracy and smaller omission numbers; (2) a total of 1,183 mine sites were identified in the study area, of which 381 abandoned mines showed a significant decreasing trend in BSP from 2016 to 2021, with a median decreasing from 98% in 2016 to 81% in 2022, indicating better vegetation recovery during this period. (3) the REM of abandoned mines generally showed a stable upward trend from 2016 to 2022, while the REM of active mines decreased year by year during this period. This study provides a systematic solution and process for identifying surface mining areas and monitoring restoration scope and ecological quality on a broader scale. It can effectively identify the process of mine restoration and ecological restoration and can be extended to other areas to provide a quantitative evaluation of mine restoration and ecological quality and support further ecological restoration decision-making.
 

surface mining; Yangtze River watershed; ecological restoration; remote sensing ecological index; google earth engine