139 / 2023-08-20 21:55:08

Quantitative influence of surface deformation process and its corresponding space-time evolution law of ecological environment caused by mining disturbance

surface deformation process;,ground subsidence;,spatiotemporal evolution law of ecological environment;,mining disturbance;,spatiotemporal coupling model;,Vegetation index,SBAS-InSAR method.

Coal mining leads to ground subsidence，and then causes serious ecological and environmental hazards. Current research focuses on surface deformation caused by mining disturbances or a certain aspect of ecological environment evolution, but lacks in-depth exploration of the coupling relationship between surface deformation and ecological environment evolution. Taking Xishan coal field in Shanxi Province as the research area, the basic data of surface deformation analysis, and then carries out dynamic monitoring of surface deformation in different periods with radar data and SBAS-InSAR method. Then we analyzed the causes of subsidence in detail from the perspective of annual average subsidence rate, cumulative subsidence and subsidence area combined with tectonic faults, groundwater and mineral resources. Secondly, by setting up subsidence center, subsidence edge and non-subsidence zones, the influence of ground subsidence caused by coal mining on surface vegetation was quantitatively analyzed combined with surface vegetation and remote sensing technology, and the vegetation coverage in the next five years was predicted by pixel dichotomy and grey prediction model. The research results show that: Land damage due to mining disturbance is mainly manifested as regional land subsidence in Xishan Coalfield which has a strong spatial correlation with mining activities, and the main subsidence areas were concentrated in Gujiao-Xishan mining areas, Qingxu-Jiaocheng mining areas, Taiyuan Basin, Banyu and Hedi village in Wenshui County; from 2010 to 2020, the land subsidence area of Xishan coalfield from 103km2 to 346km2, the areas with subsidence rates of -10~-30mm/a and >-30mm/a increased by 213.4km2 and 29.5km2 respectively. The proportions of vegetation with high fluctuation and serious degradation were 6.60% and 5.64% in the subsidence center, and its NDVI values were about 10% lower than that in the subsidence edge and non-subsidence zones. Vegetation coverage showed a wedge ascending trend from 2013 to 2020, and the prediction values of vegetation coverage obtained by GM (1,1) model also revealed this trend. The residuals of the predicted values were 0.047, 0.047, and 0.019 compared with the vegetation coverage in 2021, and the vegetation coverage was the lowest in the subsidence center, which was consistent with the law obtained by using NDVI. The proportion of severely degraded vegetation areas in the center of land subsidence is twice and five times that of the settlement edge and non-settlement areas; At the same time, its vegetation high fluctuation change is about 2.5 times that of the subsidence edge and non-subsidence area. The research results can provide scientific basis for rational mining of minerals, ecological restoration and environmental protection, and have great theoretical significance and practical value.