黑河流域地下水同位素年龄及可更新能力研究  

The groundwater in the Heihe River basin: isotope age and renewability

作　　者：阮云峰[1,2] 赵良菊[1] 肖洪浪[1] 周茅先[1] 程国栋[3] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所内陆河流域生态水文重点实验室,甘肃兰州730000 [2]中国科学院大学,北京100049 [3]中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,甘肃兰州730000

出　　处：《冰川冻土》2015年第3期767-782,共16页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(91325102;91025016;91125025)资助

摘　　要：通过对黑河流域地下水的放射性同位素如氚（T）和14C的测定,对该流域浅层和深层地下水的年龄以及其更新速率进行了估算.结果表明：整体上看,从黑河流域的上游、中游至下游,浅层和深层地下水年龄逐渐增加,地下水更新速率也逐渐增大.其中,黑河上游浅层和深层地下水平均更新速率分别为1.96%·a^-1和1.76%·a^-1,可更新能力最强;中游浅层和深层地下水平均更新速率为1.25%·a^-1和0.68%·a^-1,可更新能力次之;下游浅层和深层地下水平均更新速率分别为0.74%·a^-1和0.18%·a^-1,可更新能力最差.黑河流域不同地带地下水由于循环条件的不同,浅层和深层地下水年龄存在较大的差异.其中,中游山前平原补给条件较好,浅层和深层地下水年龄较小;中、下游远离河道地区浅层和深层地下水补给条件差,显示了更老的年龄.黑河流域埋深40 m以上的浅层地下水平均更新速率（1.13%·a^-1）高于埋深40-100 m之间的中层地下水（0.65%·a^-1）以及埋深100 m以下深层地下水（0.55%·a^-1）.因此,在黑河流域地下水开发过程中要合理开发浅层地下水,适当缩减开发深层地下水.Radioactive isotopes such as T and14 C were used to estimate the ages of groundwater,shallowand deep,as well as the renewal rates of groundwater in the Heihe River basin. The results showed that the ages and renewal rates of both shallowand deep groundwater increase gradually from the upper reaches to the middle and then the lower reaches as a whole,with the maximum mean renewal capacity of 1. 96% ·a^-1and 1. 76% ·a^-1for shallowand deep groundwater,in the upper reaches,respectively,and followed by 1. 25% · a^-1and0. 68% ·a^-1in the middle reaches,respectively,finally by 0. 74% · a^-1and 0. 18% · a^-1in the lower reaches,respectively. Based on the difference in the condition of water cycle in the Heihe River basin,large difference was found between the groundwater ages of shallowgroundwater and deep groundwater. For example,piedmont plains in the middle reaches have younger groundwater age due to the better recharge condition,and the groundwater which is far away from the river channel in the middle and lower reaches has older age. The mean renewal rate of shallowgroundwater at 0 - 40 m depth（ 1. 13% ·a^-1） is higher than that of medium layer at40 - 100 m depth（ 0. 65% · a^-1） and that of deep layer below100 m depth（ 0. 55% ·a^-1）. Therefore,exploiting groundwater should be rationally controlled from the shallowlayers and exploiting deep groundwater should be reduced properly.

关 键 词：放射性同位素 地下水年龄 可更新能力 黑河流域 

分 类 号：P641[天文地球—地质矿产勘探]