Hydrochemical processes and evolutionary mechanisms of groundwater and surface water in the Anlecun mining area: a computational study based on multivariate statistical analysis and isotope techniques

Karst water plays a vital role on population's daily needs, determining groundwater sources, chemical changes, and accurately evaluating flow paths and evolution stages is essential for proper protection and use of mining area groundwater resources.This study carried 10 sets karst groundwater and surface water samples from the Anle Village mining area.Based on multivariate statistical analysis, Piper trilinear diagrams, Gibbs diagrams, and isotopic techniques, the hydrogeochemical characteristics of karst groundwater (including contaminated and uncontaminated water samples) and surface water in the mining area were analyzed, systematically revealing their recharge sources, recharge ages, and hydrochemical evolution patterns.The results show that the uncontaminated groundwater and surface water are slightly alkaline with a prevalence of a+ N and 2+ Mg cations with3 HCO and 2-4 SO anions and 2-2+ 2 3 4 HCO -SO -Ca -Mg and 2+ 2 3 HCO -Ca -Mg , respectively.The uncontaminated samples show the high content of impurities with dominance of 2+ Ca and 2+ Mg cations and 2-4 SOanions. the uncontaminated karst groundwater and surface water are predominantly recharged by atmospheric precipitation and are influenced by evaporation.the uncontaminated karst groundwater and surface water is primarily driven by the weathering and dissolution of carbonate, sulfate, and silicate rocks.The -3NO concentration in the surface water may be associated with agricultural fertilizers, and the contaminated groundwater is closely related to mineral resource development.The research results are of great significance for understanding the circulation and evolution processes of karst groundwater and surface water in the Anle Village mining area and for the protection and utilization of water resources.