Karst aquifer protection evaluation to the Sangu spring basin under the condition of coal mining

The Sangu spring basin is a typical karst area in the north of China. It is located in the Jindong large coal base planned by the state. The problems between coal mining and water resources protection are prominent in this basin. Over the years,the large-scale explotiation of coal resources in the region has led to the decline of groundwater level and the deterioration of water quality. Therefore, it is of great significance to carry out evaluation of aquifer protection in northern karst coal base for water resources protection and sustainable economic development. In this work, an evaluation index system was established from three aspects: vulnerability of aquifer, function of aquifer and the influence of coal mining. The APH method was used to evaluate the aquifer protection in the Sangu spring basin. According to the characteristics of the coal base, the COP modified model with added indicators of coal goaf is adopted to evaluate the vulnerability of aquifer. The functional evaluation of aquifer was carried out from the capacity of water supply and ecologicalspring maintenance ability, and the impact assessment of coal mining was conducted from two aspects: mining activities and coal geological structure. The final evaluation results show that the aquifer primary protected area is located in the big karst spring , water source and surface water leakage region. The secondary protected areas include water-rich runoff zones and coal mining areas. This prediction is in line with the actual situation.