诺木洪河流域地下水水化学特征及演化规律研究  

Hydrochemistry characteristics and evolution of groundwater in Nomhon River Basin in Qinghai

作　　者：杨炳超[1] 李小等 张戈[1] 李成柱[1] 

机构地区：[1]中国地质调查局西安地质调查中心,陕西西安710054

出　　处：《西北农林科技大学学报（自然科学版）》2016年第10期214-220,共7页Journal of Northwest A&F University(Natural Science Edition)

基　　金：中国地质调查局地质调查项目"柴达木盆地循环经济试验区1:5万水文地质调查"(1212011220974)

摘　　要：【目的】对青海省诺木洪河流域地下水水化学特征及演化规律进行研究,为合理开发和保护该地区地下水提供指导。【方法】采集诺木洪河流域具有代表性的水样58个,测定水样中的Na^+、K^+、Ca^(2+)、Mg^(2+)、HCO_3^-、Cl^-、SO_4^(2-)、CO_3^(2-)、矿化度等指标,在此基础上,运用Piper三线图图示法和离子比例系数法,系统研究了地下水水化学的空间分布特征与演化规律。【结果】1由南而北,研究区地下水水化学特征呈环带状分布,主要从HCO_3·SO_4·Cl-Na·Mg·Ca、HCO_3·Cl-Mg·Na型向SO_4·Cl-Na、Cl-Na型演化转变,矿化度由小于1g/L增至10g/L以上。2溶滤作用、蒸发浓缩作用、阳离子交换作用是控制研究区地下水水化学演化的主要水化学作用,沿地下水径流方向,主要发生了石盐、石膏和长石的溶解反应、方解石和白云石的沉淀反应及Ca-Na阳离子交换反应。【结论】诺木洪河流域地下水水化学特征受水循环特征影响,戈壁滩与冲洪积平原区地下水水化学类型以HCO_3·Cl-Na·Mg为主,矿化度小于1g/L,为淡水;冲湖积平原区地下水水化学类型以Cl-Na为主,矿化度大于1g/L,为咸水甚至卤水。【Objective】Hydrochemistry characteristics and evolution of groundwater in Nuomuhong River Basin were studied to provide guidance for reasonable application and protection of groundwater.【Method】Fifty-eight water samples were collected from the basin and Na＋,K＋,Ca2＋,Mg2＋,HCO3-,Cl-,SO42-,CO32-,and salinity were measured.The spatial variation of the hydrochemistry characteristics and evolution of groundwater were studied based on piper diagram and ratio coefficients of main ions.【Result】1 From south to north,the hydrochemistry characteristics of groundwater were distributed in ring zones.The species changed gradually from HCO3·SO4·Cl-Na·Mg·Ca,HCO3·Cl-Na·Mg to SO4·Cl-Na and Cl-Na.Salinity increased from less than 1g/L to more than 10g/L.2 The hydrochemistry processes were mainly controlled by lixiviation,evaporation and ion exchange.Along the direction of groundwater,precipitation between calcite and dolomite,dissolution of gypsum,plagioclase and potassium feldspar,and cation exchange between Ca/82＋9 and Na＋ were observed.【Conclusion】The hydrochemistry characteristics of groundwater were affected by water cycle in this area.HCO3·Cl-Na·Mg was the main hydrochemistry type in Gobi and alluvial plain with salinity of less than 1g/L.Cl-Na was the main hydrochemistry type inlake plain with salinity of more than 1g/L.

关 键 词：地下水 水化学特征 演化规律 诺木洪河流域 

分 类 号：P641.12[天文地球—地质矿产勘探]