摘要
新疆喀什三角洲地下水"水质型"缺水问题较为突出,开展地下水流系统研究具有实际意义.采用水化学和环境同位素年龄测试法,在对喀什三角洲地下水含水系统划分基础上,对地下水化学和循环更新特征进行了分析研究.结果表明:三角洲含水系统由山前倾斜冲洪积平原潜水、河流冲积平原潜水和河流冲积平原承压水构成.沿地下水流向,水化学类型演化为HCO3·SO4-Ca→SO4-Ca→SO4·Cl-Mg·Na→SO4·Cl-Na,TDS增高,水质趋向盐化.山前倾斜冲洪积平原为溶滤-径流区,河流冲积平原为径流-累盐区.研究区地下水更新速率为0.03%~16.35%·a-1,具有山前倾斜冲洪积平原潜水>河流冲积平原潜水>河流冲积平原承压水的特征.利用3H估算得出,山前倾斜冲洪积平原潜水年龄为8~49 a,平均值为29 a;河流冲积平原潜水年龄为14~>50 a,其中上部潜水平均年龄为24 a,下部潜水平均年龄大于50 a.利用14C估算得出,河流冲积平原潜水为476~33623 a,平均值为8106 a;河流冲积平原承压水为5186~34578 a,平均值为30043 a,与潜水比为"更古老"的水.综合以上特征得出,喀什三角洲地下水含水系统可以划分为2个更新速率较快的局部水流系统(Ⅰ1和Ⅰ2)和一个循环滞缓的区域水流系统(Ⅱ).
The shortage of groundwater caused by poor water quality is more prominent in the Kashgar delta of Xinjiang,so it is practical significance to study groundwater flow system.Based on the divisions of groundwater aquifer system in Kashgar delta,the characteristics of the groundwater hydrochemistry and cycle regeneration were analyzed using hydrogeochemistry and environmental isotope age test methods.The research results show that the delta aquifer system consists of unconfined groundwater in piedmont sloping alluvial-diluvial plain,unconfined groundwater in river alluvial plain and confined groundwater in river alluvial plain.The evolution of groundwater hydrochemistry types is HCO3·SO4-Ca→SO4-Ca→SO4·Cl-Mg·Na→SO4·ClNa along the groundwater flow direction.With the increased TDS,the groundwater quality tends towards salinization.Piedmont sloping alluvial-diluvial plain is the main dissolution-runoff zone and the river alluvial plain is main runoff-accumulation salt zone.The groundwater renewal rate in the study area is 0.03%~16.35%·a-1,which is characterized by unconfined groundwater in piedmont sloping alluvial-diluvial plain>unconfined groundwater in river alluvial plain>confined groundwater in river alluvial plain.Estimated by 3H,the age of unconfined groundwater in piedmont sloping alluvial-diluvial plain is 8~49 a,with an average of 29 a.The age of unconfined groundwater in river alluvial plain is 14~>50 a,in which the average age of upper unconfined groundwater is 24 a,and the average age of lower unconfined groundwater is>50 a.Estimated by 14C,the age of unconfined groundwater in river alluvial plain is 476~33623 a,with an average of 8106 a.The age of confined groundwater in river alluvial plain is 5186~34578 a,with an average of 30043 a,being"older"than unconfined groundwater.Based on the above characteristics,the groundwater aquifer systems in Kashgar delta are divided into two local flow systems(Ⅰ1 andⅠ2)with faster renewal rate and a regional flow system(Ⅱ)with slow circulation.
作者
魏兴
周金龙
梁杏
乃尉华
曾妍妍
范薇
李斌
Wei Xing;Zhou Jinlong;Liang Xing;Nai Weihua;Zeng Yanyan;Fan Wei;Li Bin(College of Water Conservancy and Civil Engineering,Xinjiang Agricultural University,Urumqi 830052,China;Xinjiang Hydrology and Water Resources Engineering Research Center,Urumqi 830052,China;School of Environment Studies,China University of Geosciences,Wuhan 430074,China;No.2 Hydrogeological and Engineering Geological Team of Xinjiang Bureau of Geology and Mineral Resources Exploration and Development,Changji 831100,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2020年第5期1807-1817,共11页
Earth Science
基金
新疆自治区自然科学基金项目(No.2019D01B18)
国家自然科学基金项目(No.41662016)。
作者简介
魏兴(1993-).男,博士研究生,主要从事同位索水文地质学与地下水或地表水转化研究.ORCID:0000-0003-8602-2887,E mail:1035027480@qq.com;通讯作者:周金龙,ORCID:0000-0001-5055-0252.E-mail:zjzhoujl@163.com。
