Dynamic evolution law of water accumulation range in coal mining subsidence area with high-level groundwater

In order to study the dynamic evolution law of the water accumulation range with high-level groundwater, the working face 1031 of Wugou coal mine was taken as the research area. Based on Landsat-8 remote sensing data, the evolution law of water accumulation range above working face 1031 during 2013-2017 was summarized and the influence of factors such as net rainfall, groundwater depth and working surface propulsion distance on the evolution of water accumulation range was analyzed. The concept of the boundary angle of the water accumulation range was proposed, and the functional relationship between the angle and the mining time was established. The study found that the evolution of surface water in the coal mining subsidence area was divided into four periods:unformed, synchronous growth, residual growth, stable. The groundwater depth is negatively correlated with the daily growth of the water accumulation range. The working face advancement distance is the driving factor for the change of the water accumulation range. When the working distance is about 476 m, water is accumulated on the surface, about 5 months after stopping mining, the area of water accumulation range tends to be stable, in the synchronous growth and residual growth period, the angle generally decreases, in the stable period the angle tends to be 90ås a whole, but it fluctuates due to other factors. This study provides a theoretical basis for land use planning, land reclamation, and establishment of a land-water complex ecosystem in the coal mining subsidence area with high-level groundwater.