【作者】 郭永海； 李亚伟； 王海龙； 刘淑芬； 苏锐； 宗自华；

【Author】 GUO Yonghai,Li Yawei,Wang Hailong,SU Rui,LIU Shufen,ZONG Zihua (Beijing Research Institute of Uranirm Geology,Beijing 100029 )

【机构】 核工业北京地质研究院；

【摘要】 甘肃北山地区是我国高放废物处置库场地的主要预选区。在高放废物处置库场地选择和性能评价中,水文地球化学特征是最重要的评价因素之一。在2005至2006年期间,开展了北山地区区域水文地球化学调查,采集地下水样品60余组,本文根据样品测试结果,采用水文地球化学在综合分析方法,讨论了北山地区地下水化学特征,其主要结论是:研究区地下水主要高矿化度的咸水,地下水的pH值介于7.39～10.14之间;水温8～17℃之间;地下水总溶解固体（TDS）变化在0.7～19g/L之间,地下水的主要化学类型为Cl·SO₄-Na和SO₄·Cl-Na,其次为Cl-Na。大多数地下水样品对硫酸盐矿物,如石膏未达到饱和状态;大多数地下水对钙、镁碳酸盐矿物,如方解石已达到过饱和状态;大区域上潜水水化学的水平分带性明显,这种分带性主要受气候因素（降水量和蒸发量）和地下水循环交替条件的控制。水文地球化学特征表明,岩石溶滤和蒸发浓缩是区内地下水化学成分形成的主要作用。更多还原

【Abstract】 Beishan area in Gansu province is the main preselected area of disposal repository for high level radioactive waste（HLW） in our country.In the siting and site characterization study for high level radioactive waste repository, the groundwater chemical features are the one of the most important evaluation factors.From 2005 to 2006,the field hydrogeochemical investigation was carried out in Beishan area and more than 60 groundwater samples were collected.According to the measurement data,applying the synthetic hydrogeochemical analytical method,the paper discussed the groundwater chemical features in Beishan preselected area for China’s high level radioactive waste repository.The main conclusion is that:the groundwater in the study area is mainly saline water with high dissolved solids,7.39～10.14 pH value,8～17℃:temperature,0.7～19g/L total dissolved solids and Cl·SO₄-Na,SO₄·Cl-Na and Cl-Na chemical types.Sulphate minerals such as gypsum are undersaturated and tend to dissolve in most groundwaters and Ca-Mg carbonate minerals such as calcite are mostly oversaturated in most groundwaters in the area and tend to precipitate from groundwater.Regionally,the chemical compositions of phreatic groundwater show a clear horizontal zonation characteristic.This zonation characteristic is controlled mainly by climate factors and conditions of groundwater circulation and alternation.The hydrogeochemical features show that lixiviation and evaporation are the basic pattern forming the groundwater chemistry in the area.更多还原