Study on Water Abundance of Roof Aquifer of Coal Seam Based on Deposition Law of Formations

In order to study the water abundance of the roof sandstone aquifer of the 3-1 coal seam in the Hongqinghe Coal Mine, the sedimentary facies and the distribution of sand bodies in the mining area are analyzed by using the principle of sedimentology. On this basis, the ratio of sandstone thickness to formation thickness and the sandstone thickness were selected as the main control factors, and the water abundance of the roof sandstone aquifer was divided by using AHP and GIS methods. The results showed that the relatively richer water abundance area was located in northwest where the hydrodynamic conditions of the ancient river at the bottom of Zhiluo formation was better and the relatively medium water abundance area was widely distributed in flood plain and downstream of the ancient river with bad hydrodynamic conditions, as well as the remaining area was relatively weak, basically in the non-ancient river area.