Multi-factor evaluation for the water yield properties of coal floor aquifers, based on GIS

Groundwater inrush in mines directly threatens safe coal production. Aquifer yield plays a crucial role during water inrush. Significant accidents occur in areas where aquifer yields are strong. The yield of an aquifer is influenced by many things and, in this study, five for which data are easily acquired were selected as evaluation indices for coal-seam floor aquifer yield. They comprise specific yield, permeability, drilling fluid consumption, aquifer thickness, and fault and fold distribution. Based on these indices, a comprehensive model for evaluating water yield was constructed. Using the Ordovician limestone aquifer below the coal floor of Danhou coal mine, Hebei province, China, as an example, index data relating to aquifer yield were collected and the index weight determined. A geographic information system was used to prepare a thematic map for each driving factor and, subsequently, to superimpose them. Comprehensive water yield evaluation indexes were obtained and, finally, a zonal map of different water yield properties was developed for the research area.