Water abundance prediction of sandstone aquifers based on the distance function

Abstract

To establish a more accurate roof water abundance evaluation model and mitigate the difficulties in roof water abundance prediction and evaluation in the coal mine production process, the 2101 working face of the Yingpanhao coal mine was studied. Combined with the hydrogeological characteristics and drilling data of the study area and based on the lithology and structure, four controlling factors, including the equivalent thickness of sandstone, the lithological coefficient of sandstone, the degree of fracture development, and the sand-mud interlayer coefficient, were selected as evaluation indexes for the prediction of roof water abundance zones of sandstone aquifers. In the case of limited borehole data, the distance function was used to couple the improved analytic hierarchy process with the entropy weight method. The errors caused by subjective and objective factors were effectively reduced, and on this basis, a water abundance prediction model of roof sandstone was built. With the use of geophysical exploration results, the model predictions were combined with geophysical survey data to generate a comprehensive water abundance zone map, which divided the study area into three zones according to the water abundance. The results show that the high water abundance areas were mainly concentrated in the west of the working face, and the water abundance throughout the study area was generally low. The prediction results were verified by the data from drainage holes exposed by drilling, which provided a scientific and practical method for the prediction of the water abundance of coal seam roofs.