Spatial-temporal heterogeneity of ecological risk of land use in mining areas

In this study, the 11 towns with the most coal mines and serious surface collapses in Weishan County were selected as the areas of study, and remote sensor images and land use data were used as the data sources. From this information, distribution maps of land use type in 2000, 2005, 2010 and 2016 were obtained. Based on landscape ecology theory, an index of the ecological risk of land use was constructed. In this study, the theories of spatial statistics and geostatistics were used to determine an appropriate study scale. Spatial-temporal change and spatial heterogeneity of the ecological risk of land use in the research area were analyzed between 2000 and 2016. It was concluded that 1 km × 1 km regular grid was the best research scale. At this scale, the spatial distribution of the ecological risk of land use in the research area was concentrated and had a strong positive spatial correlation. The random variation of the land use ecological risk index on a small scale was gradually replaced by spatial structural variation on a larger scale between 2000 and 2005. The total spatial variability of ecological risk in 2005 was high. Between 2005 and 2016, the degree of spatial variability caused by random factors was increased. Between 2000 and 2016, the ecological risk of land use was characterized by the transition from medium-high and high ecological risk to medium and medium-low ecological risk. The ecological risk of deteriorated areas and obviously deteriorated areas was mainly distributed around the eastern mining area, roadside, and serious collapse areas. In addition, the ecological risk of deterioration of cultivated land on both sides of the east and west side of Weishan Lake was higher between 2010 and 2016. Over the past 17 years, the stable areas and improved areas of Weishan Lake increased significantly, with a clear decrease in the overall ecological risk.