Assessment of Water Inrush Risk Using the Fuzzy Delphi Analytic Hierarchy Process and Grey Relational Analysis in the Liangzhuang Coal Mine, China

The exploitation of deep coal seams in North China's coalfields is seriously threatened by water inrush. Water inrush is controlled by multiple factors and its processes are often not amenable to mathematical expression. To predict and prevent water inrush from the underlying Ordovician aquifer during mining of the No. 13 coal seam in the Liangzhuang coal mine, we used an innovative combination of methods to assess the risk of water inrush based on the fuzzy Delphi analytic hierarchy process (FDAHP) and grey relational analysis (GRA). Expert opinions and GRA were applied to obtain the relative importance of each of the major controlling factors, and the total weights of all factors were assigned using FDAHP. This allowed us to develop a risk index map in which the study area was divided into two zones and four subzones based on the risk index.