海原县山前地下水化学特征分析

Study on Hydro-Geochemical Characteristics in Piedmont of Haiyuan County

在海原县采集地下水及泉水样品145组,采用Piper图解法、Gibbs半对数法、离子比例法等方法,对海原县山前地下水化学特征及其形成机制、空间演化规律进行了分析研究,结果表明:从南、西华山补给区至鸭儿涧排泄区,地下水化学类型由HCO3-Ca·Mg渐变为HCO3·SO4-Ca·Mg、SO4·Cl-Na·Mg·Ca、SO4·Cl-Na·Mg,HCO3-、Ca^2+含量逐渐减少,SO4^2+、Cl^-、Na^+含量逐渐增多;干盐池为一断陷封闭盆地,水文地质单元相对独立,从盆地边缘至盆地中心沉积物颗粒逐渐变细,地下水化学类型由HCO3·SO4-Ca·Mg渐变为HCO3·SO4-Na·Mg、SO4·Cl-Na·Mg、Cl·SO4-Na·Mg;从补给区至径流区,地下水化学类型的形成以溶滤作用为主,至径流区渐变为以阳离子交替吸附作用为主,排泄区以蒸发-浓缩作用为主。

It took 145 sets of samples of groundwater and spring water from Haiyuan County and studied the chemical characteristics,formation mechanism and spatial evolution of piedmont groundwater of the county by using mathematical statistics method,Piper graphic method, Gibbs semi-logarithm diagram method,ion ratio method and isotopic method.The results show that from the recharge area of Xihua Mountain to Yaerjian drainage area,the hydro-chemical types of the groundwater are gradually changed from HCO3 -Ca·Mg to HCO3·SO4 -Ca·Mg, SO4 ·Cl-Na·Mg·Ca and Cl ·SO4 -Na·Mg,the content of HCO-3 and Ca^2+are gradually reduced,on the contrary,the content of SO4^2+, Cl- and Na+are gradually increasing.Ganyanchi is a closed depression,which hydrogeological unit is relatively independent.Sedimentary particles become smaller from the edge of depression to the center,the hydro-chemical types of the groundwater are gradually changed from HCO3 -Ca·Mg to SO4·Cl-Na·Mg·Ca and Cl ·SO4 -Na·Mg.From recharge area to drainage area,the formation of hydrochemistry are mainly impacted by filtration effect,in runoff area,the hydrochemistry is mainly impacted by cation exchange and in drainage area,the hydrochemistry is mainly impacted by evaporation and concentration.