怒江源区那曲干流河水稳定同位素沿程变化特征  

Variation characteristics of stable isotopes in water along main stream of Naqu River in source area of Nujiang River

作　　者：董国强[1,2] 翁白莎[2] 陈娟[3] 严登华[2] 王浩[2] DONG Guoqiang;WENG Baisha;CHEN Juan;YAN Denghua;WANG Hao(College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China;State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China;Division of International Cooperation, China Institute of Water Resources and Hydropower Research, Beijing 100035, China)

机构地区：[1]东华大学环境科学与工程学院,上海201620 [2]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038 [3]中国水利水电科学研究院国际合作处,北京100038

出　　处：《水利水电技术》2018年第8期108-114,共7页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金重点项目"那曲流域水源解析及气候变化的响应"(91547209);国家自然科学基金面上项目"那曲上游流域草地演变对坡面产流影响机理实验与模拟"(41571037);国家重点研发计划项目"陆地-水文耦合模式构建与全球陆地水资源演变趋势预测"(2016YFA0601503)

摘　　要：为了识别那曲流域的水循环过程,基于2016年8月,2017年1月、7月、8月、12月那曲流域采集的河水和湖水样品δ_D和δ_(18O)的测试结果,运用最小二乘法得到那曲流域夏季和冬季地表水线(surface water line,SWL)(夏季:δ_D=6.29δ_(18O)-18.01,冬季:δ_D=5.39δ_(18O)-33.54),分析了研究区河水和湖水稳定同位素时空分布特征。结果表明,河水中氢氧稳定同位素的变化具有显著的季节性差异,这可能是由河水的水源补给和蒸发作用引起的。错那湖湖水中,δ_(18O)值最大,其平均值为-9.28‰,受到不同程度蒸发分馏作用的影响,导致湖水富集重同位素。湖水对于河水中同位素和过量氘的分布具有重要的调节作用。干流河水中δ_(18O)平均值为-12.70‰,支流河水中δ_(18O)平均值为-14.88‰。以错那湖为分界点,干流河水中δ_(18O)值呈现为先增大后减小的变化趋势;过量氘(D-excess)值则呈现为先减小后增大的变化趋势。In order to identify the water cycle process of Naqu River Basin,temporal-spatial distribution characteristics of stable isotopes in the river water and the lake water within the study area are analyzed herein with the surface water line（SWL）of Naqu River Basin in summer（δD=6.29δ18O-18.01）and winter（δD=5.39δ18O-33.54）obtained through the least square method in accordance with the testing results of the river water and the lake water samples collected in August 2016 and January,July,August and December 2017 within Naqu River Basin.The result shows that significant seasonal difference is there among the variations of the hydrogen and oxygen stable isotopes,which is possibly caused by the effects of water source supplement and evaporation.In the water of Cuona Lake,the value ofδ18Ois the highest with the mean value of-9.28‰,while heavy isotopes are enriched in the lake water due to the evaporative fractionation effect to different extents.The lake water has an important effect to regulate the distributions of isotopes and D-excess in the river water.The mean value ofδ18Oin the water of the mainstream is-12.70‰and is-14.88‰in the water of the tributaries.Taking Cuona Lake as the cutoff point,the value ofδ18Oin the water of the main stream exhibits a variation trend of increasing at first and then decreasing,while the value of D-excess presents a variation trend of decreasing at first and then increasing.

关 键 词：稳定同位素 过量氘 河水 那曲流域 

分 类 号：P641.3[天文地球—地质矿产勘探] X143[天文地球—地质学]