Water protection in the western semiarid coal mining regions of China： A case study

The coal industry in China has been moving from the semiarid eastern to the drier western regions since the beginning of this century.Water protection is of the utmost concern for coal mining in these regions.Lu＇an,as one of the state coal mining bases in China,has been seeing increasingly heavier pressure for the protection of water resources.This article considers Lu＇an as an example and describes the ways these concerns may be alleviated.High mine-water utilization rates have effectively reduced wasting of water and,consequently,have reduced water demand.Using the top layers of the Ordavician as aquifuge barriers can prevent floor karst water inrush into the longwall face and can protect the regional Ordovician karst water resources at the same time.The strength of the overlying Quaternary clay can protect against roof collapse and has successfully preserved the Quaternary porous water resource.