太原盆地地下水系统水化学特征及形成演化机制

第23卷　第1期2009年2月

现　代　地　质

GE OSC IE NCE

Vol 123　No 11

Feb 12009

太原盆地地下水系统水化学特征及形成演化机制

李向全,侯新伟,周志超,刘玲霞

(中国地质科学院水文地质环境地质研究所,河北正定　050803)

收稿日期:2008208230;改回日期:2009201205;责任编辑:戚开静。

基金项目:中国地质调查局地质调查项目(1212010331301);国家自然科学基金项目(40672169)。 作者简介:李向全,男,研究员,1966年出生,水文水资源专业,主要从事水文地质、地质灾害方面的研究工作。

Email:lxql m 2003@yahoo 1com 1cn 。

摘要:在对太原盆地水文地质进行详细调查基础上,集成应用水化学统计、水化学模拟技术,系统研究了盆地地下水水化学类型、空间分布特征,并对其形成演化机制进行了系统分析,取得了一系列新的认识。按水质类型和分布特征,盆地浅层地下水(含水层埋深小于50m )大致分为盆地边缘地带浅层淡水、盆地中心浅层咸水和浅层高矿化硫酸盐水3种类型。高矿化硫酸盐水主要是由于接受了富含硫酸根离子的周边基岩水补给所致。盆地中深层孔隙水可分为盆地边缘中深层水、盆地中心中深层水和中深层混合水3种类型。浅层地下水存在2种形成机制,一种是高矿化Ca ・M g —S O 4型岩溶水的混合补给形成,另一种高矿化水是在径流演化过程中受蒸发浓缩作用影响,使地下水矿化度不断增高而形成。自盆地边缘至中心地带,中深层地下水水化学特征具有明显的水平变化规律,在盆地中心形成2个高值区,水化学类型依次为Ca ・Mg -HCO 3→Na ・Ca -HCO 3・S O 4→Na ・Mg -HC O 3・Cl →Na -HC O 3。关键词:太原盆地;地下水;水化学特征;演化机制

中图分类号:X523;P641 文献标志码:A 文章编号:1000-8527(2009)01-0001-08

Hydrogeochem i ca l Character isti cs and For ma ti on Evoluti ona l M echan is m

of the Groundwa ter System s i n the Ta i yuan Ba si n

L I Xiang 2quan,HOU Xin 2wei,ZHOU Zhi 2chao,L IU L ing 2xia

(Institute of Hydrogeology and Environm ental Geology,Chinese A cade m y of Geological Sciences,Zhengding,Hebei 050803,China )

Abstract:I n the Taiyuan basin,the statistical methods and geoche m ical model have been syste matically used t o study the hydr oche m ical types of gr ound waters,s patial distributi on of geoche m istry,and evoluti onal mechanis m.The results sho w that the shall ow gr oundwater of the basin can be divided int o the fresh gr oundwater in the bor 2der of the basin,the salt gr oundwater in the center of the basin,the high m ineralizati on degree sul phate gr ound 2water .The third type of the shall o w gr oundwater has been recharged by the bedr ock fissure gr ound water rich in S O 2-

4in the border of the basin .The moderate deep gr ound waters of the basin have been divided int o the moder 2ate deep gr ound water in the border of the basin,the moderate deep gr oundwater in the center of the basin,and the moderate deep m ixed gr ound water .There are t w o kinds of hydr oche m ical mechanis m s of the gr ound water evoluti on:the first is that the gr oundwater is recharged by the high m ineralizati on sul phate karst gr oundwater;the second is that the increase of T DS of gr ound water is attributed t o the evaporati on during the evoluti on p r ocess .Fr o m the border t o the center in the Taiyuan basin,the moderate deep gr oundwater obvi ously show the hydr oche m ical distributi onal regularities,and there are t w o high value areas in the center of the Taiyuan basin .The hydr oche m ical types of the gr ound water are successively Ca ・Mg 2HCO 3→Na ・Ca 2HCO 3・S O 4→Na ・Mg 2HCO 3・Cl →Na ・Mg 2HCO 3・Cl →Na 2HCO 3.

Key words:Taiyuan basin;gr oundwater;hydr ogeoche m istry characteristic;evoluti onal mechanis m