安固里淖流域地下水水化学特征与水质评价

Hydrochemical Characteristics and Water Quality Evaluation of Groundwater in Angulinao Basin

安固里淖内陆河流域为严重缺水区,多年来,该区域的地下水研究集中于水资源量及其开发方向,地下水水化学特征和水质情况受到了忽视,其中硝酸盐污染、原生氟化物超标、排泄区TDS过高是安固里淖内陆河流域最突出的水质问题。该研究采集流域地下水样品共258组进行全分析检测,分析水化学特征并评价水质。结果表明,流域补给区水化学类型以HCO3-Ca为主,阴离子类型沿流向向HCO3·SO4、HCO3·Cl、Cl·HCO3、Cl型过渡;受土地利用类型影响,部分地区硝酸盐超标严重,超标率达44.3%,来源主要为农业化肥;排泄区蒸发浓缩和原生地质环境共同导致流域部分地区氟化物超标片状分布,威胁当地居民饮水安全并有地方病风险;流域下游地下水埋深浅,且内陆河流域蒸发量大,导致排泄区TDS普遍较高。

Angulinao inland river basin is a serious water shortage area.For many years,groundwater research in this area has focused on water resources and its development direction.The hydrochemical characteristics and water quality of groundwater have been ignored.Among them,nitrate pollution,primary fluoride excess and high TDS in discharge area are the most prominent water quality problems in Angulinao inland river basin.In this study,258 groups of groundwater samples were collected for full analysis and detection to analyze the hydrochemical characteristics and evaluate the water quality.The results show that HCO3-Ca is the main hydrochemical type in the recharge area of the basin,and the anion type is transiting to HCO3·SO4,HCO3·Cl,Cl·HCO3,Cl along the flow direction.Influenced by the land use type,the nitrate in some areas exceeds the standard seriously,and the exceeding rate reaches 44.3%.The main source is agricultural chemical fertilizer.The evaporation and concentration in the discharge area and the primary geological environment together lead to the excessive and flaky distribution of fluoride in some areas of the basin,threatening the drinking water safety of local residents and bring the risk of endemic diseases.The groundwater in the lower reaches of the basin is shallow,and the evaporation in inland river basin is large,resulting in the high TDS in the discharge area.