摘要
根据2019年8月对汾河干流水文参数和碳酸盐参数的调查,初步探讨了溶解无机碳(DIC)及同位素值(δ^13CDIC)的沿程变化及其影响因素.结果显示,源头水DIC为2756μmol/kg,δ^13CDIC为-9.6‰,土壤CO2输入和碳酸岩化学风化可能是其主要来源;在太原市区上游的水库影响区,较强的初级生产使得水体DIC(平均值为2377μmol/kg)和CO2分压(p CO2)(平均值为552μatm)偏低,δ^13CDIC(平均值为-5.2‰)偏正,而在市区下游的水坝滞流影响区,城市污水的大量输入和有机物的降解使得DIC(>4900μmol/kg)和p CO2(>5000μatm)显著升高,δ^13CDIC(<-10.3‰)偏负;在流经主要粮食产区的汾河下游,δ^13CDIC偏正(^-8.0‰)于源头,可能与C4植被(如玉米)的存在有关.可见,人为干扰已成为影响汾河DIC沿程变化的重要因素,表现为大气CO2强源的城市下游水坝滞留区在今后需受到更多关注.
Based on hydrographic and carbonate data collected from an investigation in the main stream of the Fenhe River in August 2019,the variations of dissolved inorganic carbon(DIC)and isotope value(δ^13CDIC)along the river as well as their possible factors were preliminarily discussed.The results showed that the DIC concentration was 2756μmol/kg and theδ^13CDIC value was-9.6‰at the headstream,and CO2 input from soil and carbonate chemical weathering may be the main sources.In the upstream reservoir-affected area of Taiyuan downtown,due to strong primary production both DIC(the average value was 2377μmol/kg)and partial pressure of CO2(pCO2)(the average value was 552μatm)were lower,andδ^13CDIC(the average value was-5.2‰)was more positive compared to those at the headstream,whereas in the downstream dam stagnation affected area because of large amounts of municipal sewage inputs and degradation of organic matter both DIC(>4900μmol/kg)and p CO2(>5000μatm)increased substantially,andδ^13CDIC became more negative(<-10.3‰).In the lower reaches of the Fenhe River flowing through the main grain production areas,theδ^13CDIC value(^-8.0‰)was more positive than that at the headstream of the river,possibly related to the existence of C4 plants such as corn.Overall,human disturbance had become a very important factor affecting the DIC variations along the Fenhe River.Moreover,the dam stagnation affected area at the downstream of the city,which acts as a strong CO2 source of the atmosphere,should be paid more attention in the future.
作者
李云霄
黄潇
邹英杰
薛亮
樊文华
王改玲
LI Yun-xiao;HUANG Xiao;ZOU Ying-jie;XUE Liang;FAN Wen-hua;WANG Gai-ling(College of Resource and Environment,Shanxi Agricultural University,Taigu 030801,China;College of Environmental Science and Engineering,Nanjing University of Information Science and Technology,Nanjing 210044,China;Ecological Environmental Monitoring Center of Weifang,Weifang 261041,China;First Institute of Oceanography,SOA,Qingdao 266061,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2020年第9期3871-3878,共8页
China Environmental Science
基金
山西省优秀博士来晋工作奖励资助项目(SXYBKY2018020)
山西农业大学科技创新基金资助项目(2018YJ21)。
