Risk assessment of Cretaceous water inrush in the Ordos Basin based on the FAHP-EM

Abstract

Abstract A study on the risk of Cretaceous water inrush in the Ordos Basin in China is of great significance to the safe production and environmental protection of the western coal seam. This paper selects the following five key influencing factors for Cretaceous water inrush: the coal seam mining thickness, rock quality designation, distance between the top boundary of the water-conducting fracture zone and the bottom boundary of the Cretaceous system, the thickness of the Cretaceous aquifer, and the height of the water head. Furthermore, based on an analysis of geological and hydrogeological conditions of the Yingpanhao coal mine, the comprehensive weights of these factors were found using a fuzzy analytic hierarchy process and the entropy method (FAHP-EM) to be 0.27, 0.25, 0.22, 0.08, and 0.18, respectively. This paper describes the use of ArcGIS's spatial overlay analysis to create a risk assessment zoning map using these weightings. By comparing the evaluation results of the FAHP-EM and the water inrush coefficient method, it is shown that the FAHP-EM provides additional insight in assessing the risk of coal seam roof water inrush. The research results of this paper provide a theoretical basis for coal mining safety in western China to assess water inrush.