[关键词]
[摘要]
在水文地质调查和样品采集分析的基础上, 采用描述性统计、离子比例系数、Piper 三线图、Gibbs 图及剖面 Schoeller 图等方法对呼和浩特盆地地下水展开了系统研究。研究结果表明: ( 1) 地下水化学成分形成过程明显受到 地形地貌和地下水赋存条件的控制。山前冲洪积扇前缘的潜水与承压水主要受碳酸盐和硫酸盐的风化溶解作用影 响, 以 H CO32Ca# Mg 型地下水为主; 而最终至冲湖积平原中心, 蒸发浓缩过程和阳离子交替吸附过程成为水化学 成分主控因素。( 2) 由冲湖积平原边缘至中心, 水化学类型快速演变, 阳离子经 Ca# Mg # Na 型过渡为 Mg # Na 型、Na# Mg 型并最终以 Na+ 占绝对优势, 而阴离子则由 H CO3 # Cl 型、Cl # H CO3 型、Cl # SO4 型最后演变为 Cl 型。( 3) 在地表水系和灌区附近, 混合效应明显改变了地下水化学成分。此外, 人类活动的影响同样不可忽视, 在人 口密集区及主要农业区周边出现高氮地下水, 甚至导致 Cl # NO3 型水形成。
[Key word]
[Abstract]
On the basis o f hydr ogeo lo gical inv est igat ion and sample collectio n, w e used descriptive statistics, ionic ratio s, Piper trilinear diag ram, Gibbs diag ram, and Scho eller fig ur es to sy stematica lly st udy the g ro undwater in H ohhot basin. T he r esults show ed: ( 1) T he chemical com po nents of gr oundwat er ar e obviously co nt ro lled by the topog raphic and geomor phic facto rs and gr oundwat er occurr ence conditions. T he unco nfined and co nfined w ater in alluv ial2pr oluv ial pla in ar e mainly affected by weathe2 ring2dissolut ion of car bo nate and sulphate, and they ar e mainly the H CO32Ca # Mg type. In the center of alluv ial2lacustrine plain, evapo ratio n and ion2ex change reactio ns become the main co ntr ol pro cesses fo r hy dr ochemical components. ( 2) Fr om the edg es to the center o f alluvial2lacustrine plain, t he hydrochemical ty pes ev olv e r apidly. The catio ns evolve from the Ca# Mg # Na type to the Mg # Na and Na# M g ty pes, and end up w ith Na+ as the only dominant type. The anions evo lve fr om the H CO3 # Cl type, Cl # HCO3 type, Cl# SO4 type, to Cl ty pe in the end. ( 3) Near the surface water sy stem and irrig ation areas, the mix ing effect has obvio usly chang ed t he chemical compo sitio n of g ro undwater. In addition, t he influence o f human act ivit ies cannot be igno red. Aro und densely po pulated areas and major agricultural r eg io ns, ther e is hig h2 nit rog en gr oundw ater, which even caused the fo rmation of Cl# NO3 type gr oundw ater.
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[基金项目]
中国地质调查局国土资源大调查项目( 1212011121163) ; 中国地质科学院基本科研业务费专项( YYWF201626) ; 河北地质大学博 士科研启动基金项目( BQ201610)