Chemical and Strontium Isotopic Compositions of the Hanjiang Basin Rivers in China:Anthropogenic Impacts and Chemical Weathering

作     者：Zhifang Xu Chao Shi Yang Tang Hongyin Han Key Laboratory of Engineering Geomechanics,Institute of Geology and Geophysics, Chinese Academy of Sciences,100029 Beijing,China Graduate University of Chinese Academy of Sciences,100049 Beijing,China Institute of Geochemistry,Chinese Academy of Sciences,550002 Guiyang,Guizhou,China Key Laboratory of Biologic Geology and Environmental Geology under Ministry of Education, China University of Geosciences,430074 Wuhan,China 

会议名称：《中国科学院地质与地球物理研究所第11届（2011年度）学术年会》

会议日期：2012年

学科分类：08[工学] 081501[工学-水文学及水资源] 0815[工学-水利工程] 

基　　金：supported by the National Natural Science Foundation of China(No.40773077) Key Projects in the National Science & Technology Pillar Programme(No. 2008BAD98B04) 

关 键 词：Hanjiang River South-to-North water transfer project Sr isotopic ratio Chemical weathering CO2 consumption 

摘      要：The Hanjiang River,the largest tributaries of the Changjiang(Yangtze) River, is the water source area of the Middle Route of China’s South-to-North Water Transfer *** chemical and strontium isotopic compositions of the river waters are determined with the main purpose of understanding the contribution of chemical weathering processes and anthropogenic inputs on river solutes,as well as the associated CO consumption in the carbonate-dominated *** major ion compositions of the Hanjiang River waters are characterized by the dominance of Ca and HCO,followed by Mg and *** increase in TDS and major anions(Cl,NO,and SO) concentrations from upstream to downstream is ascribed to both extensive influences from agriculture and domestic activities over the Hanjiang *** chemical and Sr isotopic analyses indicate that three major weathering sources(dolomite,limestone,and silicates) contribute to the total dissolved *** contributions of the different end-members to the dissolved load are calculated with the mass balance *** calculated results show that the dissolved load is dominated by carbonates weathering,the contribution of which accounts for about 79.4%for the Hanjiang *** silicate weathering and anthropogenic contributions are approximately 12.3 and 6.87%,*** total TDS fluxes from chemical weathering calculated for the water source area(the upper Hanjiang basin) and the whole Hanjiang basin are approximately 3.8×10 and 6.1×10 ton/year,respectively. The total chemical weathering(carbonate and silicate) rate for the Hanjiang basin is approximately 38.5 ton/km/year or 18.6 mm/k year,which is higher than global mean *** fluxes of CO consumption by carbonate and silicate weathering are estimated to be 56.4×10 and 12.9×10 mol/year,respectively.