祁连山东端地表及地下水水化学时空变化特征

Temporal-spatial variation of surface and undergroundwater chemistry in the eastern part of Qilian Mountains

于2016~2017年5-9月采集祁连山东端(乌鞘岭、古浪、天祝;)的地表水和地下水样品进行水化学分析,综合运用统计分析、Piper三线图、Gibbs图以及离子比值等方法探究了祁连山东端地表水和地下水主要离子组成特征、来源以及时空变化.结果表明,祁连山东端地表水和地下水化学组成中优势阳离子为Ca^2+和Na^+,Ca^2+的平均浓度为76.897mg/L,占比73.89%;Na^+的浓度为16.592mg/L,占比15.94%.优势阴离子为HCO3~和SO4^(2),HCO3^-浓度190.117mg/L,占比68.71%;其次是SO4^2-,平均值为67.565mg/L,占比为24.42%.乌鞘岭河水、地下水,天祝河水、地下水的水化学类型为HCO3^--Ca^2+型,古浪河水、地下水水化学类型为HCO3^--Ca^2+-Mg^2+型,处于水化学易变区.不同水体离子来源于岩石风化,主要受碳酸盐与硅酸盐风化溶解共同作用控制,人类活动在一定程度上贡献了水体的离子来源.不同水体主要离子浓度的时间变化特征各不相同,整体上大部分水体的离子浓度随时间变化不明显,总体趋势较平缓.

Surface water and undergroundwater were collected from the eastern part of Qilian Mountains(Wushaoling,Gulang,Tianzhu)from May to September,2016~2017.Water chemical analysis,statistical analysis,Piper three-line diagram,Gibbs diagram and ion ratio were used to explore the main ion composition,source and temporal&spatial variation of surface water and undergroundwater in the area.The result shows that the main cations of theeastern part of the surface water and undergroundwater in Qilian Mountainsare Ca^2+and Na^+.The average concentration of Ca^2+is 76.897mg/L,accounting for 73.89%.AndNa+is 16.592mg/L,accounting for 15.94%.The dominant anions are HCO3^-and SO4^2-.The concentration of HCO3^-is 190.117mg/L,accounting for 68.71%.SO42-is 67.565mg/L,accounting for 24.42%.The water hydrochemistry type is HCO3^--Ca2+concerning Wushaoling River water,Wushaoling undergroundwater,Tianzhu riverand Tianzhuunderground water.In the light of Gulangriver water and its underground water,the type is HCO3^--Ca^2+-Mg^2+.Ions ofdifferent waters are from rock weathering,meanwhile affected by carbonate and silicate weathering and dissolution combined,and human activity is alsocontributed.The time-varying characteristics of the main ions concentration in different water bodies are different.In general,the ions concentration of most water bodies does not change significantly with time,and the overall trend is relatively flat.