双河洞洞穴系统岩溶地表水-地下水主要离子化学特征及其来源分析

Chemical Characteristics and Source Analysis of Main Ions in Karst Surface Water and Groundwater in Shuanghe Cave System

为揭示喀斯特洞穴区域地表水、地下水水化学特征及其水化学变化的影响因素,采用数理统计、Piper三线图、Gibbs图、氢氧同位素关系图、离子相关性及离子比值关系等方法对研究区2015年4月~2017年3月的40组地表水水样和253组地下水水样数据进行分析。研究结果表明:双河洞区域地表水、地下水pH均呈碱性,TDS值总体上属淡水和微咸水,TH值属软水和微硬水。地表水中阳离子主要以Ca^(2+)、Mg^(2+)离子为主,阴离子主要以HCO_3^-离子为主;水化学类型主要为HCO_3-Ca和HCO^(2+)_3-Ca·Mg。地下水中阳离子主要以Ca^(2+)、Mg离子为主;阴离子主要以HCO_3^-和SO_4^(2-)离子为主,水化学类型主要为HCO_3·SO_4-Ca·Mg、SO_4·HCO_3-Ca·Mg和HCO_3-Ca·Mg。通过Gibbs图、离子相关性、主要离子比值关系可以看出,主要离子组分均来自碳酸盐岩和硫酸岩盐的风化溶解,同时可能存在人为活动的影响。研究区水化学组分是区域地质地貌条件、水-土-岩相互作用、农业活动等因素综合导致的。研究结果对岩溶区地表水和地下水的开发利用、管理和保护具有重要的科学意义。

To explore the hydrochemical characteristics of surface water and groundwater in Karst cave area,the influencing factors of hydrochemical changes are revealed. Using mathematical statistics,Piper diagram,Gibbs diagram,hydrogen oxygen isotope diagram,ion correlation and ion ratio relation,data of 40 sets of surface water samples and 253 sets of groundwater samples from April 2015 to March 2017 in the study area were analyzed. The results show that the surface water and ground water pH in Shuanghe area are alkaline,and TDS values are generally freshwater and brackish water,and TH values are soft water and slightly hard water. The cations in surface water are mainly Ca^(2+) and Mg^(2+) ions,while the anions are mainly HCO_3^-. The hydrochemical types are mainly HCO_3-Ca and HCO_3-Ca·Mg. The cations in groundwater are mainly Ca^(2+) and Mg^(2+) ,while the anions are mainly HCO_3^- and SO_4^(2-). The hydrochemical types are mainly HCO_3·SO_4-Ca·Mg,SO_4·HCO_3-Ca·Mg and HCO_3-Ca·Mg. Through the Gibbs diagram,ion correlation and main ion ratio relation,it is found that the main ion components come from the dissolution and dissolution of carbonate rock and sulfuric acid rock salt,at the same time,there may be human impact. The hydrochemical composition of the study area is a combination of regional geological and geomorphic conditions,water soil rock interaction,agricultural activities and other factors. The research results have important scientific significance for the development,utilization,management and protection of surface water and groundwater in karst area.