博尔塔拉河上游河谷地区水化学特征及水质评价

An assessment of groundwater,surface water,and hydrochemical characteristics in the upper valley of the Bortala River

为了解博尔塔拉河上游河谷地区地下水和地表水水化学特征及水质状况,以36组水样数据为基础,运用Piper图、相关性分析、Gibbs图和离子比值等方法研究水化学特征及其影响因素,采用熵权-贝叶斯水质评价模型、Wilcox图和USSL图等方法进行水质评价。水化学分析结果显示:(1)研究区机井水、泉水和河水均为弱碱性淡水,总硬度(TH)、溶解性总固体(TDS)、F-和NO_(3)^(-)整体表现为:机井水>泉水>河水,HCO_(3)^(-)和Ca^(2+)分别为优势阴、阳离子,博尔塔拉河上游水中各组分含量沿程呈增加趋势;(2)区内机井水和泉水水化学类型以HCO_(3)-Ca型为主,河水水化学类型主要为HCO_(3)-Ca型和HCO_(3)·SO_(4)-Ca·Na型,水化学特征主要受控于岩石风化作用,水化学组分主要来源碳酸盐岩风化,且存在蒸发盐岩溶解,同时也受阳离子交换作用和人类活动的影响。饮用水水质评价显示,82.6%的机井水和100%的泉水适合饮用或基本适合饮用,或进行适当处理后适合饮用;不适合饮用的水样点主要受Fe、F-和NO_(3)^(-)等超标严重影响;对于灌溉水质评价而言,区内河水、机井水和泉水水质较好均适合灌溉。

This paper examined the hydrochemical characteristics and water quality status of groundwater and surface water in the upper valley of the Bortala River,Xinjiang.The examination was based on 36 groups of water sample data.Hydrochemical characteristics and their influencing factors were studied by Piper diagram,correlation analyses,Gibbs diagram and ion ratio,and the entropy-Bayesian water quality evaluation model,Wilcox and USSL diagrams were used to evaluate water quality.Results of hydrochemical analyses showed the following:(1)the mechanical well water,spring water,and river water in the study area were weakly alkaline fresh water,and total hardness(TH),F−,NO_(3)^(-) and total dissolved solids were aligned as mechanical well water>spring water>river water,whereas HCO_(3)^(-) and Ca^(2+) were the dominant anions and cations,respectively.Contents of each component in the upper Bortala River increased along the river.(2)The main hydrochemical types of mechanical well water and spring water in the area were the HCO_(3)-Ca type,and main hydrochemical types of river water were the HCO_(3)-Ca and HCO_(3)·SO_(4)-Ca·Na types.Hydrochemical characteristics were controlled mainly by rock weathering,and hydrochemical components were mainly from carbonate rock weathering.Evaporation rock dissolution also occurred and it was affected by cation exchange and human activities.The water quality evaluation of drinking water showed that 82.6%of mechanical well water and 100%of spring water were suitable for drinking,basically suitable for drinking,or suitable for drinking after proper treatment.Water sample points that were not suitable for drinking were affected mainly by excessive Fe,F−,and NO_(3)^(-).River water,well water,and spring water were suitable for the evaluation of irrigation water quality.