Types of water hazards in China coalmines and regional characteristics

In China, coal-forming period spans extensively in time and space, creating complex geological and hydrogeological conditions. The difficulties in water hazards control are rarely seen elsewhere in the world. To provide an effective engineering approach to water hazards control, this article puts forward a categorization of 30 commonly seen water hazards based on factors such as types of water sources and conductors with factual records of water hazards and accidents in China coalmines. Furthermore, on account of the coal storing conditions in the coalmining areas, this article has outlined six water hazards zones with emphasis on the types of water hazards requiring precautions, as well as an analysis on formation mechanisms of each water hazard and key technological points for preventive engineering. This article is aimed to provide references for countries and regions with intensive coalmining needs and to facilitate experience sharing.