重庆市南川区南部岩溶地下水水文地球化学特征

以重庆市南川区南部地区岩溶地下水为研究对象，通过野外调查和取样测试分析，对研究区内149件地下水样品进行水化学常规分析和微量重金属元素分析，结果表明:研究区内地下水化学类型以HCO3-Ca·Mg、HCO3-Ca和HCO3-SO4-Ca型为主。地下水中主要阴阳离子HCO3-、SO42-、Ca2+和Mg2+浓度均表现出与含水岩组相对应的关系，即碳酸盐岩类岩溶水＞碳酸盐岩夹碎屑岩水＞碎屑岩水。地下水中Mg2+ /Ca2+摩尔比值表明研究区内绝大部分地下水径流过程中以方解石和白云石的共同溶解为主。地下水中微量重金属元素含量整体偏低，绝大部分水质都在Ⅲ类水标准以内，只有极个别点受到污染导致部分重金属组分偏高 

Hydrogeochemical characteristics of karst groundwater in southern Nanchuan district of Chongqing

This work focused on the karst groundwater in southern Nanchuan District of Chongqing city. We have analyzed hydrochemical components and trace heavy metals in 149 pieces of samples. The results indicate that the hydrochemical types of groundwater are dominated by HCO3-Ca Mg , HCO3-Ca and HCO3·SO4-Ca. Most major chemical components of groundwater are Ca2+，Mg2+，HCO3-and SO42-，which show the corresponding relation with the water-bearing rock groups, i.e. carbonate karst water > carbonate rock and clastic rock water > clastic rock water. The ratio of Mg2+/Ca2+ in underground water shows that the co-dissolution of calcium carbonate and dolomite is dominant in the groundwater runoff process. The content of trace heavy metals is generally on the low side in groundwater. Most of the water quality is within the category III of water standard, only a few contaminated spots lead to some heavy metals on the high side.