Hydrogeochemical Characteristics and Evolution of Karst Groundwater in Heilongdong Spring Basin, Northern China

Understanding the impact of natural processes and anthropogenic activities on geochemical evolution is vital for groundwater protection utilization. This research was devoted to identifying water quality status main controlling factors hydrochemical karst by combining hydrogeochemical indicators with multi-isotope analysis techniques in Heilongdong Spring Basin, North China. The results showed that area meteoric origin, dissolution carbonate minerals dominant water–rock interactions. Meanwhile, positive negative cation exchange occurred process. types were HCO3-Ca·Mg HCO3-Ca recharge area, while predominant HCO3·SO4-Ca·Mg HCO3·SO4-Ca runoff discharge area. Under influence coal mining other factors, average concentrations major ions kept rising where mines distributed, SO42? changed most study In addition, sewage from agricultural production domestic sources had also negatively impacted regional as evidenced increasing NO3? Cl? contents Quaternary sediment groundwater, Permian bedrock a small portion groundwater. These helpful explain mechanism gradual changes provided scientific basis effective management utilization