六盘水矿区关键带岩溶水水化学演化特征及驱动因子

Characteristics and Driving Factor of Hydrochemical Evolution in Karst Water in the Critical Zone of Liupanshui Mining Area

贵州六盘水矿区地表水-地下水交换频繁,是重要的生活和工、农业用水水源,为保障该地区用水安全和可持续性,以六盘水典型矿业集中开发区为研究对象,于2015年9月共采集水样33件.运用水化学、相关性分析和离子比值法等进行了综合研究,结果表明:地下水化学类型大多为Ca-HCO3型,部分为Ca-SO4型;地表水大多为Ca-HCO3、Ca-SO4型;矿井水为NaHCO3,而酸性矿山排水为Ca-SO4型.水体中Ca2+、Mg2+和HCO3-呈显著正相关性,主要由碳酸盐岩溶解控制,Na+和K+主要为硅酸盐岩溶解,Cl-主要来源于城镇生活污水,NO3-主要受农业生产影响,SO42-来源多样.矿业活动、城镇化和农业生产影响了水体离子组成,矿业活动还会加速碳酸盐岩的溶解,三者使水体水化学类型发生明显变化.喀斯特岩溶关键带人类活动复合影响下,矿业活动是岩溶水系统中水化学特征变化的关键驱动因子.

The surface water and groundwater which are critical resources for daily life,industrial and agricultural production exchange frequently in Liupanshui mining area.To ensure the security and sustainability of water system in the karst critical zone,thirty-three water samples were collected from the typical Liupanshui mining area in September 2015.They were analyzed by using the methods of hydrochemistry,correlation analysis and ion ratios.The results show most groundwater hydrochemical type was CaHCO3 type,and some was Ca-SO4 type.Most surface water was Ca-HCO3 type and Ca-SO4 type.Differently,the mine waste water was Na-HCO3 type and the acid mine waste water was Ca-SO4 type.There was a significant positive correlation between Ca2+,Mg2+and HCO3-which was mainly controlled by reaction between water and carbonate,and some Na+and K+were controlled by reaction between water and silicate.The sources of Cl-were mainly sewage,most of NO3-were affected by agricultural production,and SO42-came from multiple sources.Mining activities,urbanization and agricultural production have affected the compositions of water ions,in addition mining activities have accelerated the dissolution of carbonate.These three factors have made significant changes in the hydrochemistry types.Under these compound influences affected by human activities,mining activities are the key driving factors for the changes of hydrochemical characteristics in water system of the karst critical zone.