羊卓雍错湖水稳定同位素空间变化特征研究  

The Spatial Distribution of Stable Isotopes in YamzhoYumco Lake

作　　者：臧娅琳[1,2] 王建力[1] 田立德[2,3] 翁永标[2] 文蓉[2] 宗继彪[2] 

机构地区：[1]西南大学地理科学学院,重庆400715 [2]中国科学院青藏高原研究所环境变化与地表过程重点实验室,北京100101 [3]中国科学院寒区旱区环境与工程研究所冰冻圈国家重点实验室,兰州730000

出　　处：《西南大学学报（自然科学版）》2014年第4期127-132,共6页Journal of Southwest University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(41025002);全球变化研究国家重大科学研究计划(2010CB951702);中国科学院战略性先导科技专项(B类)(XDB03030100)

摘　　要：通过分析西藏南部羊卓雍错湖水表面及垂直剖面氢氧同位素的空间变化以及氢氧稳定同位素的关系,讨论了羊卓雍错湖水蒸发过程中稳定同位素的空间分布特征以及湖水的内循环过程.根据取得的587个水样的同位素分析结果,发现羊卓雍错湖水中稳定同位素存在有规律的空间变化,虽然变化的幅度不大,但反应了湖水的内循环过程.羊卓雍错湖水中的δ18 O及过量氘表现出一致的空间变化,有河流注入的周边区域δ18 O低,而中部偏东侧湖水中的δ18 O最高而过量氘最低.这种空间差异表明湖水在循环过程中存在从河流入湖口到湖泊中部的缓慢流动,并最终完全在湖中心蒸发掉.湖水西北部的同位素较低值与来自冰川融水的卡鲁雄曲河水的注入有关,而西南部的低值表明普莫雍错的湖水流入了羊卓雍错.湖水垂直剖面δ18 O的变化很小,接近仪器测量精度,说明湖水的垂直混合较充分.In a study made of Yamdrok Lake（Yamzho Yumco）in western Tibetan Plateau,the spatial variation of hydrogen and oxygen stable isotopes at the lake surface and along the vertical profile of the lake water were investigated,and the characteristics of spatial variation of the stable isotopes and the inner circulation process of the lake water were discussed.A total of 587water samples were analyzed in terms of stable isotopes.This analysis showed that the spatial variation of the stable isotopes of the lake water varied with small amplitude.However,the inner circulation process of the lake water was clearly demonstrated by the stable isotope distribution.Theδ18 O and d-excess values of the lake water showed consistent spatial variations.Lowδ18 O values were observed in the area with river inflow into the lake,while the highestδ18 O and lowest d-excess values were recorded in the mid-eastern part of the lake.Such a spatial difference indicated that in the water circulation process the lake water smoothly flowed from the river entrance to the middle part of the lake and was ultimately evaporated there.Furthermore,a spatial difference was also observed in the northwestern and southwestern part of the lake.The lowerδ18 O value in the northwestern part of the lake was supposed to be closely related to the inflow of the glacial-melted water from the Karuxung River while the lower value of the southwestern part indicated the water inflow from Pumo Yongcuo Lake（Pumo Yum Tso Lake）.The vertical difference inδ18 O value of the lake water was limited,which suggested that the lake water was well-mixed vertically.

关 键 词：湖水 氢氧稳定同位素 空间变化 羊卓雍错 湖水循环 

分 类 号：P333[天文地球—水文科学] P339[水利工程—水文学及水资源]