疏勒河流域玉门-瓜州盆地地下水化学演化特征  

Geochemical Evolution of Groundwater in the Yumen- Guazhou Region of Shule River Basin

作　　者：赵玮[1] 何建华[1] 马金珠[1] 

机构地区：[1]兰州大学西部环境教育部重点实验室,西部环境与气候变化研究院,甘肃兰州730000

出　　处：《干旱区研究》2015年第1期56-64,共9页Arid Zone Research

基　　金：国家自然科学基金项目(41271039)资助

摘　　要：综合运用水文地球化学技术,研究疏勒河流域玉门—瓜州盆地地下水化学特征及演化规律。地下水化学类型从无明显特征逐渐向SO2-4-Na+型水演化。岩盐、芒硝、石膏的溶解对Ca+、Na+、SO2-4及Cl-的影响较大,同时决定着地下水的化学类型。反向阳离子交换对Ca2+、Mg2+的浓度起到了重要作用,芒硝与岩盐溶解的Na+促进了地下水与含水层介质的离子交换,随着交换到水中的Ca2+、Mg2+离子浓度增加,碳酸盐沉淀,HCO-3减少。另外,河水和反硝化作用也对地下水的SO2-4、NO-3和K+的含量有影响。该研究可为采用水化学研究地下水资源属性提供一定的借鉴意义。Groundwater supply in an inland river basin of arid zone plays a significant role in desertification,storms and economic development. With the implementation of Gansu Hexi Corridor Project,the population increased very fast in the Yumen- Guazhou Region of the Shule River basin,a semi-arid area with high evaporation but low precipitation. Availability of water resources has become a growing problem and seriously and negatively affect the sustainable development of the region. In this study,we investigated the chemical types and geochemical evolution of the groundwater in the region by using hydrogeochemical technologies. The results showed that the water-rock reaction of groundwater was determined by the relationships of different ions,such as the relationships of SO4^2-and Na^＋,SO4^2-and Ca^2＋,Cl^-and Na^＋,HCO3^-and Na^＋,（ Ca^2＋＋ Mg^2＋）-（ HCO3^-＋ SO4^2-） etc. We also used the chloro alkaline indices to examine the effect of the reverse cation exchanges. The groundwater evolved gradually from no-dominated ions to SO4^2-- Na^＋dominated type,the advantage of the alkaline earth metal ions replaced by the alkali metal cations,while the weak acid ions were permuted by the strong acid ions. The relationships among Na^＋and SO4^2-,Cl^-and Na^＋,and Ca^2＋and SO4^2-indicated the dissolution of rock salt,glauber＇s salt and gypsum which significantly affected the concertration of Ca^2＋,Na^＋,SO4^2-and Cl^-. As a result,the chemical characteristics of the groundwater were determined by these ions. Reverse cation exchange played an important role on the concentration of Ca^2＋and Mg^2＋. This reaction was accelerated by the preceding hydrogeochemical evolution,especially the dissolution of the glauber＇s salt. With the increase of the Na^＋,it can cause the cation exchange between the Na^＋of the groundwater and Ca^2＋or Mg^2＋of the aquifer. This study provided an overall view on the groundwater types and geochemical evolutions in the region. The results had important implications for

关 键 词：地下水 水文地球化学 疏勒河流域 玉门—瓜州盆地 

分 类 号：P641.3[天文地球—地质矿产勘探]