在2012 年北京岩溶水资源勘查成果和以往资料的基础上, 对北京市大兴- 通州隐伏区岩溶水水化学特征、 水质演化规律以及水质恶化原因进行了研究, 结果表明, 大兴、通州两个储水构造之间的水力联系较弱, 岩溶水 水化学特征不同。通州地区岩溶水为H CO3 # SO42Na # Ca 型, 总硬度、溶解性总固体较低, 整体水质良好, 且与 1998 年相比没有发生明显变化。大兴地区岩溶水为HCO32 Ca# Mg 型, 总硬度、溶解性总固体均较高, 其中大兴 黄村- 东高地一带水质较差, 其它地区水质良好。与2001 年相比, 大兴地区岩溶水水质发生恶化, 总硬度和溶解 性总固体浓度明显升高, 且污染范围逐渐扩大。经分析, 引起大兴地区岩溶水水质恶化的原因主要有两个: ( 1) 上游垃圾填埋渗滤液和地表污水渗入岩溶水; ( 2) 大量开采岩溶水, 改变地下水动力场和岩溶水的赋存条件, 促 使岩溶水水质恶化。

Based on the surv ey results o f kar st water in 2012 and previous data in Beijing, the hydrochemical char act eristics, the water qualit y evo lutio n, and the causes of g roundw ater quality deter ior atio n o f cover ed karst w ater in Dax ing2Tongzhou of Bei2 jing w ere investigated. The results showed that the hy dr aulic connection betw een the two gr oundwat er stor age structures in Daxing and To ng zho u is w eak and the hy dr ochemical cha racteristics ar e differ ent. The ka rst water type is mainly HCO3 # SO42 Na# Ca in To ng zho u. The total hardness and total dissolved so lids ar e low and the w ater quality is go od in the area There is no obvio us chang e in water qua lity compar ed with that in 1998. The karst w ater type is mainly HCO32Ca# Mg in Dax ing. The to tal har dness and total disso lved solids ar e high. The qua lit y is poo rer in H uangcun2Dongg aodi ar ea. T he water quality deter ior ates and the total har dness and total disso lv ed solids increase compared w ith those in 2001. T he karst g ro undwater is po lluted and the pollutio n sco pe ex pands g radually in Dax ing . Ther e ar e tw o main causes of w at er quality det erio ration in Dax ing: ( 1) landfill leachat e and po llut ed surface w ater enter into the upstream of karst water ; ( 2) long2term excessive ex ploitat ion of ka rst gr ound2 w ater changes the g r oundwater hydrody namic field and stor age conditions of kar st w ater.

北京岩溶水资源勘查评价工程项目