The Response of Carbonate System to Watershed Urbanization Process in a Semi-Arid River  

作　　者：LI Yunxiao DANG Jiajia HUANG Xiao YANG Hong WANG Xiao LI Lina BAI Jie CHEN Xi 

机构地区：[1]Department of Environmental Science,College of Resource and Environment,Shanxi Agricultural University,Taigu 030801,China [2]Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control,Collaborative Innovation Center of Atmospheric Environment and Equipment Technology,School of Environmental Science and Engineering,Nanjing University of Information Science and Technology,Nanjing 210044,China [3]Department of Geography and Environmental Science,University of Reading,Whiteknights,Reading RG66AB,UK [4]Marine Agriculture Research Center,Tobacco Research Institute,Chinese Academy of Agricultural Sciences,Qingdao 266101,China 5 [5]Key Laboratory of Marine Environmental Science and Ecology,Ministry of Education,College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China

出　　处：《Journal of Ocean University of China》2024年第4期991-1002,共12页中国海洋大学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (NSFC) (No.41376123);the Youth Project of Shanxi Basic Research (Nos.20210302124317,201901D211383);the Research and Promotion Project of Water Conservancy Science and Technology in Shanxi Province (No.2023GM41);the Science and Technology Innovation Fund of Shanxi Agricultural University (No.2018YJ21)。

摘　　要：Different from rivers in humid areas,the variability of riverine CO_(2) system in arid areas is heavily impacted by anthropogenic disturbance with the increasing urbanization and water withdrawals.In this study,the water chemistry and the controls of carbonate system in an urbanized river(the Fenhe River)on the semi-arid Loess Plateau were analyzed.The water chemistry of the river water showed that the high dissolved inorganic carbon(DIC)concentration(about 37 mg L^(-1))in the upstream with a karst land type was mainly sourced from carbonate weathering involved by H_(2)CO_(3) and H_(2)SO_(4),resulting in an oversaturated partial pressure of CO_(2)(pCO_(2))(about 800μatm).In comparison,damming resulted in the widespread appearance of non-free flowing river segments,and aquatic photosynthesis dominated the DIC and pCO_(2) spatiality demonstrated by the enriched stable isotope of DIC(δ^(13)CDIC).Especially in the mid-downstream flowing through major cities in warm and low-runoff August,some river segments even acted as an atmospheric CO_(2) sink.The noteworthy is wastewater input leading to a sudden increase in DIC(>55 mg L^(-1))and pCO_(2)(>4500μatm)in the downstream of Taiyuan City,and in cold November the increased DIC even extended to the outlet of the river.Our results highlight the effects of aquatic production induced by damming and urban sewage input on riverine CO_(2) system in semi-arid areas,and reducing sewage discharge may mitigate CO_(2) emission from the rivers.

关 键 词：dissolved inorganic carbon stable carbon isotope carbonate weathering aquatic photosynthesis sewage input the Fenhe River 

分 类 号：X143[环境科学与工程—环境科学]