青海湖沙柳河流域夏季河水和地下水水化学特征

Hydrochemical characteristics of river water and groundwater in Shaliu river basin of Qinghai Lake in summer

河水和地下水的水化学特征能够反映流域水环境的特点和水质情况.本文以青海湖沙柳河流域为研究区,选取夏季典型月份进行了河水和地下水样品采集及可溶性离子含量的测定,对青海湖沙柳河流域夏季河水和地下水的离子含量特征、水化学类型、离子来源和灌溉适宜性进行了研究.结果显示:(1)青海湖沙柳河流域夏季河水和地下水的pH平均值分别为7.59和7.12,电导率(EC)平均值分别为365.17μs·cm^(-1)和592.93μs·cm^(-1);河水和地下水的阳离子平均浓度顺序依次为Ca^(2+)>Mg^(2+)>Na^(+)>K^(+)>Li^(+)>NH_(4)^(+),阴离子平均浓度顺序为HCO_(3)^(-)>SO_(4)^(2-)>Cl^(-)>NO_(3)^(-)>NO_(2)^(-)>F-.Piper三线图结果显示该流域夏季河水和地下水水化学类型均以HCO_(3)^(-)Ca·Mg和HCO_(3)^(-)Ca型为主.(2)Gibbs图结果显示,夏季河水和地下水Na^(+)/(Na^(+)+Ca^(2+))质量浓度比值范围为0.03~0.62,Cl^(-)/(Cl^(-)+HCO_(3)^(-))质量浓度比值范围为0.01~0.18,表明岩石风化作用是控制整个沙柳河流域夏季河水和地下水水化学组分的主要因素.(3)青海湖沙柳河流域夏季河水和地下水钠百分比(Na^(+)%)平均值均为15%,钠吸附比(SAR)平均值分别为0.37和0.46,表明该流域夏季河水和地下水很适宜灌溉.

The hydrochemical characteristics of river water and groundwater can reflect the characteristics of water environment and water quality on the watershed scale.Took Shaliu river basin of Qinghai Lake as the research area,this study studied the characteristics of ion content,hydrochemical types,ion sources and suitability of irrigation for river water and groundwater in Shaliu river basin of Qinghai Lake based on collecting samples of river water and groundwater in typical month of summer,as well as measuring their soluble ion content.The results showed that:(1)The average pH values of river water and groundwater were 7.59 and 7.12,respectively,and the mean Electrical conductivity(EC)values were 365.17μs·cm-1 and 592.93μs·cm-1;The order of the average cation concentration of river water and groundwater was Ca^(2+)>Mg^(2+)>Na^(+)>K^(+)>Li^(+)>NH_(4)^(+),the order of average anion concentration was HCO_(3)^(-)>SO_(4)^(2-)>Cl^(-)>NO_(3)^(-)>NO_(2)>F^(-).The results of Piper trigram showed that the hydrochemistry of river water and groundwater in the basin in summer mainly belonged to HCO_(3)^(-)Ca·Mg and HCO_(3)^(-)Ca types.(2)Gibbs chart results showed that the mass concentration ratios of Na^(+)/(Na^(+)+Ca^(2+))and Cl^(-)/(Cl^(-)+HCO_(3)^(-))of river water and groundwater in summer ranged from 0.03 to 0.62,and the mass concentration ratios of Cl^(-)/(Cl^(-)+HCO_(3)^(-))ranged from 0.01 to 0.18,indicating that rock weathering was the main factor controlling the chemical composition of river water and groundwater in the whole Shaliu river basin in summer(3)The average sodium percentage(Na+%)of river water and groundwater in the Shaliu river basin of Qinghai Lake in summer was 0.15%,the mean sodium adsorption ratios(SAR)was 0.37 and 0.46 respectively,suggesting that the river water and groundwater in Shaliu river of Qinghai Lake in summer were suitable for irrigation.