水化学在新疆伊犁河谷地下水循环中的指示作用

Indicative effects of hydrochemistry on groundwater circulation in the Yili River Valley of Xinjiang

在分析研究区水文地质条件基础上,沿地下水运动方向,重点研究典型剖面水化学在地下水循环演化的指示意义。结果表明:"1号剖面"潜水主要水化学组分浓度在地貌类型(强倾斜砾质、缓倾斜含砾细土、冲洪积细土平原区)分界部位浓度上升,出现峰值。由北向南水化学类型依次为HCO_3—Ca、HCO_3·SO_4—Ca·Mg、HCO_3·SO_4—Ca·Na。"2号剖面"主要阳离子与阴离子具有相同的变化规律,在沿程变化图中出现了一个明显的拐点,即水样F4W04点。从水样点YN01W20到F4W04点,如Ca2+从188.4 mg/L降至48.1 mg/L等。由北向南水化学类型依次为HCO_3·SO_4—Ca·Na、HCO_3·SO_4—Ca·Mg、HCO_3—Ca。水化学结果指示了存在局部循环系统、中间循环系统,地下水以水平方向运移演化特征为主,循环交替强度由北向南逐步减弱,并且地下水循环速率与所处地貌类型紧密相关。

On the basis of analyses of hydrogeological conditions of the study area,the indicative effects of hydrochemistry on groundwater circulation evolution along the direction of groundwater movement are analyzed by using two sections as the starting points. The results indicate that hydrochemical concentration of the major compositions of the ＂ Section 1 ＂unconfined aquifer shows a rise in the boundary parts of landform types（ strongly inclined gravel,gently sloping gravel soil,alluvial prouvial fine soil plain） and reaches the peak.From north to south follows such water chemical types as HCO_3—Ca,HCO_3·SO_4—Ca·Mg,and HCO_3·SO_4—Ca·Na type. The chemical concentrations of the major compositions in the＂ Section 2＂vary with the same rule,appearing with a clear turning point along the change figure at the point of the water samples F4WO_4. From the points of the water samples YN01W20 to F4W04,concentrations of Ca2 ＋falls from 188. 4mg / L to 48. 1 mg / L. From north to south follows such water chemical types as HCO_3·SO_4—Ca·Na,HCO_3·SO_4—Ca · Mg and HCO_3—Ca type. The hydrochemical results indicate that there exist local and intermediate circulation systems, groundwater circulation is of main horizontal migration evolution characteristics,the cycle intensity gradually weakens from north to south,and the groundwater circulation rate is closely related to the geomorphic types.