西藏得不日错—拉果错湖链形态、水文与水化学特性  

Morphologic, Hydrological and Chemical Characteristics of the Debuer–Lakkor Co Lake Chain in Tibet

作　　者：饶娇萍 贾沁贤[1] 刘喜方[1] 王洪平[3] 罗玉虎 RAO Jiao-ping;JIA Qin-xian;LIU Xi-fang;WANG Hong-ping;LUO Yu-hu(MNR Key Laboratory of Saline Lake Resources and Environments,Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037;China University of Geosciences(Beijing),Beijing 100083;Nanjing Municipal Bureau of Land and Resources,Nanjing,Jiangsu 210005;Shaanxi Provincial Land Engineering Construction Group Co,Ltd.,Xi’an,Shaanxi 710075)

机构地区：[1]中国地质科学院矿产资源研究所,自然资源部盐湖资源与环境重点实验室,北京100037 [2]中国地质大学(北京),北京100083 [3]南京市国土资源局,江苏南京210005 [4]陕西省土地工程建设集团有限责任公司,陕西西安710075

出　　处：《地球学报》2019年第5期737-746,共10页Acta Geoscientica Sinica

基　　金：中国地质调查局地调工作项目(编号:DD20160025);国家自然科学基金项目(编号:40573056)联合资助~~

摘　　要：得不日错-拉果错湖链包括三个微小型上游淡水湖和一个92 km^2的末端盐湖,在青藏高原湖链中是一个微型湖链。研究发现,该湖链是一个陆地、湖泊和河流空间分布清晰的小流域;但湖泊的补水量与其隶属的次级集水盆地面积无正比关系,地下水对湖链进行了跨越空间顺序的补给,且明显与湖岸线发育度(SDI)有关。湖水潴留时间差异极大,源头湖泊得不日错仅为4.39天,而末端湖泊拉果错长达1 586.96天(4.35年)。在水质特征上,湖链中三个上游湖泊相似性极显著,而末端湖泊则与基布茶卡和扎布耶北湖极为相似,表明藏北高原湖泊水化学的演化具有相同趋势。湖链中,大多数湖泊水化学成分的含量,随着湖泊在湖链中位置的降低而逐渐增加;但K+在湖泊内是消耗过程,在河道内却是一个增益过程;Ca^2+的趋势是随着湖链水体下行浓度逐渐减少;与1978年对比,拉果错湖水盐度下降了23.98%,与青藏高原湖泊湖水淡化趋势相吻合;但SO4^2-和CO3^2-表现出含量大幅上升的异常变化,上升幅度分别为127.77%和288.95%,原因有待探明。总之,青藏高原湖泊的水源补给特征值得从事西藏湖泊水文研究者注意。Being a mini lake chain among the lake chains in the Tibetan Plateau,the Debuer-Lakkor Tso lake chain consists of three mini-to-small upstream freshwater lakes and one 92 km^2 terminal saline lake(Lagkor Co).Researches indicate that this lake chain is a small watershed with clear spatial distribution of land,lakes and rivers;however,the lake water recharge capacity is not directly proportional to the area of sub-catchment basin to which the lakes belong,instead,the lake chain is recharged by the groundwater system developed underneath limestone landform in a manner of spanning spatial sequence via subterranean rivers,and the recharge capacity distinctly is related to shoreline development index(SDI).The lake retention time varies dramatically,as the headstream lake,Debure Co,has a lake retention time of only 4.39 days,while the terminal lake,Lagkor Co,has a lake retention time up to 1 586.96 days(4.35 years).In terms of water quality characteristics,three upstream lakes in the lake chain are very significantly similar,while the terminal lake is extremely similar to Jibu Caka and North Zabuye Lake that have no direct recharge relationship with it,indicating that the lakes in the Northern Tibetan Plateau have the same tendency of hydrochemical evolution.The concentrations of most components in the lake chain gradually increase with descending location of a lake in the lake chain.However,K+undergoes a depletion process in the lakes and follows a rising process in the river courses;Ca^2+concentration follows a tendency of decreasing with the lake chain water body flowing forwards.The lake water salinity of Lagkor Co fell by 23.98%over 30 years after 1978,in agreement with the lake water freshening tendency of the lakes in the Tibetan Plateau;however,the SO4^2- and CO3^2- values showed abnormal change,i.e.,dramatic rise,the former rose by 127.77%,and the latter by 288.95%.Their causes remain to be looked into.In short,such groundwater-derived recharge characteristics of the lakes in the Tibetan Plateau shall be taken

关 键 词：西藏 得不日错—拉果错湖链 水化学 

分 类 号：P512.32[天文地球—地质学]