Subsidence prediction and susceptibility zonation for collapse above goaf with thick alluvial cover: a case study of the Yongcheng coalfield, Henan Province, China

Mine collapse is a common geological hazard associated with mining areas. This study analyzes mine collapse above the Yongcheng mining area located on the Huanghuai Plain in eastern Henan Province, China. The aim is to predict surface subsidence and evaluate associated disaster risks in goaf with thick alluvial cover. The surface deformation above seven mined coalfields and six unmined coalfields was calculated using the probability integration method. The results showed that the final maximum ground subsidence would be 7.25 m for the Suburban mine and 5.3 m for the Xinzhuang mine. As part of a broader study, land subsidence was also measured over a 1-year period in 2012-2013 by interferometric point target analysis using Radarsat-2 satellite synthetic aperture radar. Interferometric displacement maps were validated with leveling data. Based on the principles of fuzzy mathematics and the analytical hierarchy process, a susceptibility assessment system was developed to define the risk from mine collapse for the coalfields across the mining area. A hazard-zoning map was also produced using the spatial analysis function of ArcGIS. These research results can serve as a reference for farmland reclamation, town planning, and the restoration of the natural environment in this area.