Quantifying the spatiotemporal patterns and environmental impacts of surface coal mining in the Xilingol Steppe, Inner Mongolia

Surface coal mining is one of the most environmentally destructive human disturbances. This study provides the first comprehensive assessment of the speed and scale of coal mining and its major environmental impacts in the Xilingol Steppe, Inner Mongolia from 1990 to 2015, using remote sensing data and landscape metrics. Our results show that during this period the number of surface coal mining areas (SCMAs) increased from 40 to 504 (about 13 times), while the size of SCMAs increased from 3.21 km² to 283.62 km² (greater than 88 times). The rapid expansion of SCMAs greatly fragmented the steppe landscape, consumed huge amounts of water, damaged rivers and wetlands, and substantially reduced grassland productivity. We estimated that the amount of water consumed by coal mining increased from 2.35 million m³ in 1990 to 242.61 million m³ in 2015 (more than 103 times), negatively affecting all six major rivers and most wetlands in the region. About 222 km² of steppes were eradicated, resulting in a grassland production loss of 7.17×10¹⁰ g C. Our findings indicate that surface coal mining has transformed the steppe landscape and devastated its ecosystem function and services, posing a major threat to the environment of the region. Future studies need to focus on more in-depth integrative assessments of environmental, economic, and social impacts of surface coal mining to seek sustainability solutions for the region.