基于2015年8月在研究区采集的81个地下水化学和同位素数据，分析了塔城盆地北区承压水化学类型分布特征，并结合研究区水文地质条件，采用背景比拟法、Gibbs图、氘盈余模型、离子比值法、氯碱指数及钠吸附比等水化学分析方法，分析了地下水化学形成作用及其演化机制。结果表明：承压含水层普遍赋存水质较好的淡水，水化学类型以HCO3-Ca型（Ca·Mg型、Ca·Na型）水为主。随地下水径流方向，承压水TDS及水化学类型呈较好的水平分带规律，即从承压水的上游区，沿区域地下水流向，地下水TDS逐渐升高，水化学类型由HCO3-Ca型水，演化为SO4·HCO3-Ca·Na型和SO4-Ca·Na型水。承压水化学特征，主要受水岩作用控制，蒸发作用对其影响有限，而且基本未受人类活动影响。整体上，在上游区，承压水化学组成主要受碳酸盐矿物和正向阳离子交替吸附作用的影响，而在中、下游区主要受石膏溶解影响。在个别径流路径上，正向阳离子交替吸附作用对地下水化学组成的影响超过矿物溶滤作用。

Based on 81 samplings in August 2015,the characteristics in distribution of total dissolved solids (TDS) and hydrochemical types of confined groundwater in the north Tacheng Basin are identified,and the evolution mechanisms explored from the perspective of evaporation,leaching and ion exchange by applying the hydrochemical analysis methods such as analogue method,Gibbs plot,excess deuterium model,ion ratios,chloro alkaline index and sodium adsorption ratio (SAR).The results show that the confined groundwater with TDS less than 1.0 g/L and HCO3-Ca type water (or HCO3-Ca·Mg type water, HCO3-Ca·Na type water) are widely distributed in the study area.The TDS and hydrochemical types of confined groundwater present horizontal zonation in the direction of groundwater runoff.From recharge area to discharge area of the confined groundwater,the TDS gradually increases,and the hydrochemical type successively transfers from HCO3-Ca type water to SO4HCO3-Ca·Na type water and SO4Ca·Na type water.Hydrochemical composition of the confined groundwater mainly depends upon leaching and ion exchange.In upstream areas,hydrochemical composition of the confined groundwater is mainly affected by dissolution of carbonate mineral and positive cation exchange,while in the midstream and downstream areas,mainly affected by gypsum dissolution.In individual runoff paths,effect of the positive cation exchange on the hdyrochemical composition of groundwater is more significant than that of leaching.

中国地质调查局地质调查项目 (12120115047801)；国家自然科学基金(41302192)；河北省自然科学基金(D2018504011)