[Hydrochemical Characteristics and Control Factors of Groundwater in Shunping County, Hebei Province]

In order to study the chemical characteristics and ion source of groundwater and further serve the scientific development and management of water resources in Shunping County. A total of 33 groups of karst water and 12 groups of pore water samples were collected systematically in Shunping County, and the hydrochemical types, composition characteristics, and main controlling factors of various types of groundwater were analyzed by using Gibbs diagram, ion ratio relation, and multivariate statistical analysis methods, and the contribution rates of various sources to groundwater solutes were evaluated. The results showed that the pore water and karst water in the study area were weakly alkaline, with TDS ranging from 245.89 to 430.00 mg·L^-1 and 223.54 to 1347.80 mg·L^-1, respectively. The anion components of groundwater were mainly HCO₃^- and Ca²⁺. Groundwater in the study area could be grouped into PW1 and PW2 pore water and KW1, KW2, and KW3 karst water. PW1 and KW1 were HCO₃-Ca·Mg type, PW2 was HCO₃·Cl-Ca·Mg type, KW2 was HCO₃·NO₃-Ca·Mg type, and KW3 was SO₄-Ca·Mg type with high salinity. The weathering of carbonate rock mainly composed of dolomite and silicate rock mainly composed of albiar and potassium feldspar were the main material sources of groundwater, and their contributions to each water body were 39.69% to 66.13% and 11.87% to 58.38%. Sewage discharge and fertilizer use in human activities had significant effects on KW2 groundwater and PW1, PW2, and KW1 groundwater, respectively. In addition, the contribution rate of atmospheric precipitation to each water body ranged from 1.09% to 7.94% on average.