乌梁素海区域地下水水化学特征及成因分析

Hydrochemical Characteristics and Genesis of Groundwater in Wuliangsuhai Lake Area

运用地下水系统理论及水文地球化学分析方法对乌梁素海周边地下水水化学特征及成因进行了分析。结果表明:(1)研究区地下水整体呈弱碱性,乌梁素海与潜水均为微咸水,承压水为淡水,(2)乌梁素海水化学类型为Cl-Na型,潜水水化学类型主要为Cl-Na型和Cl-Ca·Mg型,由补给区到排泄区,水化学类型由重碳酸型向盐酸型演变,承压水水化学类型主要为HCO_(3)-Ca型和Cl-Na型,(3)研究区地下水主要受蒸发浓缩作用和水-岩相互作用的控制,蒸发浓缩和离子交换是区域地下水中Na+富集的主要原因,(4)研究区地下水中的硝酸盐来源为人畜粪便和生活污水的排放。

This study examined the hydrochemical characteristics and genesis of groundwater around Wuliangsuhai Lake with the theory of groundwater system and hydrogeochemical analysis method. The results showed that:(1) the groundwater in study area is weakly alkaline,the Wuliangsuhai Lake and the unconfined groundwater are brackish water,the confined groundwater is freshwater.(2) The hydrochemical type of Wuliangsuhai Lake is Cl-Na type;the hydrochemical types of unconfined groundwater are mainly Cl-Na type and Cl-Ca ·Mg type. From recharge area to discharge area,the hydrochemical types evolve from bicarbonate type to hydrochloric acid type.The chemical types of confined groundwater are mainly HCO_(3)-Ca type and Cl-Na type.(3) Groundwater in the study area is mainly controlled by evaporation and water-rock interaction. Evaporation and ion exchange are the main reasons for Na+ enrichment in groundwater.(4) The sources of nitrate in the groundwater of study area are human and animal excrement and the discharge of domestic sewage.