青海湖布哈河流域枯水期氢氧同位素和氡同位素分布特征及其意义  

The distribution characteristics and significance of stable(δD and δ~(18)O)and radon-222 isotopes in the Buha River basin of Qinghai Lake during dry season

作　　者：何炳毅 杨英魁 孔凡翠[1] 左进超 范志平 雷占昌 蒋常菊 王建萍[1] 凌智永[1] 郑雁莉 HE Bingyi;YANG Yingkui;KONG Fancui;ZUO Jinchao;FAN Zhiping;LEI Zhanchang;JIANG Changju;WANG Jianping;LING Zhiyong;ZHENG Yanli(Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining,Qinghai 810008,China;University of Chinese Academy of Sciences,Beijing 100049,China;Qinghai University,Xining,Qinghai 810016,China;Shenzhen Research Institute,University of Hong Kong,Shenzhen,Guangdong 518057,China;Qinghai Nuclear Industry Testing Center,Xining,Qinghai 810016,China;Qinghai Hydrological and Water Resources Survey Center,Xining,Qinghai 810001,China)

机构地区：[1]中国科学院青海盐湖研究所,中国科学院盐湖资源综合高效利用重点实验室,青海省盐湖地质与环境重点实验室,青海西宁810008 [2]中国科学院大学,北京100049 [3]青海大学,青海西宁810016 [4]香港大学深圳研究院,广东深圳518057 [5]青海省核工业检测试验中心,青海西宁810016 [6]青海省水文水资源测报中心,青海西宁810001

出　　处：《地质学报》2023年第6期2042-2053,共12页Acta Geologica Sinica

基　　金：青海科技厅项目(编号2021-ZJ-755);中国科学院青年创新促进会项目(编号2018468);中国科学院重点部署项目(编号ZDRW-ZS-2020-3);国家自然科学基金项目(编号41702268);第二次青藏高原综合科学考察研究项目(编号2019QZKK0805)联合资助的成果。

摘　　要：查明青海湖布哈河流域地下水-地表水相互作用对指导青海湖国家公园生态建设和生态保护具有重要意义。本文通过水化学、稳定同位素(δD和δ^(18)O)和放射性氡同位素(^(222)Rn)研究了青海湖布哈河流域地下水-地表水相互作用。结果显示,布哈河流域河水和地下水水化学主要受水岩作用影响,而孔隙水和湖水主要受蒸发结晶影响。氢氧同位素具有空间变异性。地下水与河水^(222)Rn活度中游高而上下游低;孔隙水中^(222)Rn活度值在横向上随着离岸距离的增加而降低,纵向上随着深度增加而表现出降低的趋势。地表水体的^(222)Rn活度时间分布特征表现出明显的日间高、夜间低的昼夜循环特征。表明枯水期河水主要由地下水进行补给,中上游地区和下游地区地下水补给量占比分别为96%和87%,但是降水发生时地下水-地表水相互作用发生了转换,降水前主要是地下水补给地表水,降水后则是地表水补给地下水,占比达98%。本研究为进一步开展咸水湖及世界其他地区的类似研究提供了有益借鉴和参考。Investigating the surface water-groundwater interactions is of considerable significance for guiding the ecological construction and protection of the Qinghai Lake National Park.This study investigated the hydrochemistry,stable isotopes(δD and δ~(18)O) and radioisotopes(~(222)Rn) to identify the surface water-groundwater interactions.The results show that the hydrochemistry of river water and groundwater were mainly affected by water-rock interaction,while the pore water and lake water were mainly affected by evaporation crystallization.The hydrogen and oxygen have spatial variability during surface water-groundwater interaction along the drainage basin.The ~(222)Rn activities of groundwater and river water were higher in the middle reaches than in upstream and downstream.The ~(222)Rn activities of pore water decreases with the increasing offshore distance and depth.~(222)Rn activities of lake water and river water over the monitoring period shows a typical diel cycle,much higher at daytime and lower in the nighttime,indicating that groundwater discharged to river during dry seasons,and upper and middle stream and downstream accounted for 96% and 87%,respectively.This phenomenon occurred before precipitation.But there has been a shift in precipitation,that is river water discharged to groundwater,and accounted for 98%.This study contributes to useful reference of saline lake in worldwide.

关 键 词：^(222)Rn 氢氧同位素 水化学 地下水-地表水相互作用 青海湖流域 

分 类 号：P342[天文地球—水文科学]