Hydrochemical characteristics and element contents of natural waters in Tibet, China  

作　　者：TIAN Yuan YU Chengqun LUO Kunli ZHA Xinjie WU Jianshuang ZHANG Xianzhou NI Runxiang 

机构地区：[1]Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China [2]University of Chinese Academy of Sciences, Beijing 100049, China [3]Xi'an University of Science and Technology, Xi'an 710054, China

出　　处：《Journal of Geographical Sciences》2015年第6期669-686,共18页地理学报（英文版）

基　　金：National Key Technologies R＆D Program in the 12th Five-Year Plan of China, No.2011 BAD 17B05-4, No.2011BAC09B03; National Key Basic Research Program of China （973 Program）, No.2014CB238906; National Natural Science Foundation of China, No.40872210, No.41172310, No.40171006

摘　　要：Sixty water samples （35 groundwater samples, 22 surface water samples and three hot-spring water samples） were collected at 36 points from villages and towns in Lhasa city, Nagchu （Nagqu） prefecture, Ali （Ngari） prefecture and Shigatse （Xigaze） prefecture （Tibet） in 2013 to study the hydrochemical characteristics and element contents of natural waters. The concentrations of elements were determined in the water samples and compared with the concentrations in water samples from other regions, such as southeast Qinghai, south Xinjiang, east Sichuan and west Tibet. The hydrochemical species in different areas were also studied. Water in most parts of Tibet reaches the requirements of the Chinese national standard and the World Health Organization international standard. The pH values of the water samples ranged from 6.75 to 8.21 and the value for the mean total dissolved solids was 225.54 mg/L. The concentration of arsenic in water from Ali prefecture exceeded the limit of both the Chinese national standard and the international standard and the concentration of fluoride in water from Shuanghu exceeded the limit of both the Chinese national standard and the international standard. The main hydrochemical species in water of Tibet is Ca （HCO3）2. From south to north, the main cation in water changes from Ca^2＋ to Na^＋, whereas the main anions in water change from HCO3^- to Cl^- and SO4^2-. The chemistry of river water and melt water from ice and snow is dominated by the rocks present at their source, whereas the chemistry of groundwater is affected by many factors. Tectonic divisions determine the con- centrations of the main elements in water and also affect the hydrochemical species present.Sixty water samples （35 groundwater samples, 22 surface water samples and three hot-spring water samples） were collected at 36 points from villages and towns in Lhasa city, Nagchu （Nagqu） prefecture, Ali （Ngari） prefecture and Shigatse （Xigaze） prefecture （Tibet） in 2013 to study the hydrochemical characteristics and element contents of natural waters. The concentrations of elements were determined in the water samples and compared with the concentrations in water samples from other regions, such as southeast Qinghai, south Xinjiang, east Sichuan and west Tibet. The hydrochemical species in different areas were also studied. Water in most parts of Tibet reaches the requirements of the Chinese national standard and the World Health Organization international standard. The pH values of the water samples ranged from 6.75 to 8.21 and the value for the mean total dissolved solids was 225.54 mg/L. The concentration of arsenic in water from Ali prefecture exceeded the limit of both the Chinese national standard and the international standard and the concentration of fluoride in water from Shuanghu exceeded the limit of both the Chinese national standard and the international standard. The main hydrochemical species in water of Tibet is Ca （HCO3）2. From south to north, the main cation in water changes from Ca^2＋ to Na^＋, whereas the main anions in water change from HCO3^- to Cl^- and SO4^2-. The chemistry of river water and melt water from ice and snow is dominated by the rocks present at their source, whereas the chemistry of groundwater is affected by many factors. Tectonic divisions determine the con- centrations of the main elements in water and also affect the hydrochemical species present.

关 键 词：element concentrations hydrochemical species water chemistry water quality TIBET 

分 类 号：TQ533.6[化学工程—煤化学工程] T-652.1[一般工业技术]