Risk Assessment of Water Inrush in an Underground Coal Mine Based on GIS and Fuzzy Set Theory

A systematic method was developed to evaluate the risk of water inrush through a coal seam floor using the geographic information system (GIS) and the fuzzy set theory. The main geological and hydrogeological indicators that control water inrush were first considered using a fuzzy mathematics approach, in which fractal analysis was carried out to quantify the fault's characteristics. The degree of membership was determined using GIS, the weight of every factor was considered by calculating the entropy in accordance with Shannon's information entropy theory, and the level of risk of the evaluated object was derived using the maximum membership principle. The approach was validated by a case study at the Chensilou mine in Henan Province, China, where the aquifers that underlie an exploitable coal seam, II2, were made impermeable by grouting. Data from Nov. 2014 to April 2016 shows that the risk of water inrush was reduced in Panel 2517 of the II2 coal seam, that there were no serious disturbances in this panel and no groundwater inrush through the floor. This method can be a powerful tool for systematically assessing the risk of water inrush through the floor, since the influence of several factors can be quantitatively considered in accordance with the geological and mining conditions.