| 引用本文: | 易子涵,李思悦,唐薇,李玉英.三峡库区不同城镇化梯度下河流pCO2动态及驱动因素.湖泊科学,2020,32(4):1020-1028. DOI:10.18307/2020.0411 |
| YI Zihan,LI Siyue,TANG Wei,LI Yuying.Dynamics and driving factors of the river pCO2 in the Three Gorges Reservoir area with urbanization gradients. J. Lake Sci.2020,32(4):1020-1028. DOI:10.18307/2020.0411 |
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| 摘要: |
| 为研究河流溶解性CO2（二氧化碳）对城镇化的响应，于2018年8月对三峡库区3条具有不同城镇化强度的河流——汝溪河、南河和桃花溪进行野外在线监测及取样分析，测定了样品有机质（溶解性有机碳DOC）、营养元素（溶解性总氮DTN、溶解性总磷DTP）；利用ArcGIS解译各流域的土地利用组成，并利用碳酸盐平衡方程，通过pH、Alk （碱度）、水温计算不同城镇化梯度河流的pCO2（CO2分压）.结果表明：建设用地占比从低到高依次为：汝溪河 < 南河 < 桃花溪，河流pCO2依次为1790±1210、2006±3546、4094±4218 μatm，与河流的城镇化梯度变化一致，河流水-气界面呈现为CO2源；DOC、DTN浓度、Alk、电导率在各河流间呈现显著性差异.DOC、DTN、DTP浓度和Alk的变化规律与河流的城镇化梯度一致.研究发现城镇化进程增加水体的pCO2，引起区域城镇扩张进程中河流CO2释放通量的增加，结论支持强人为活动影响增加河流碳释放的假设. |
| 关键词: 城镇化梯度 三峡库区 二氧化碳分压 环境因子 |
| DOI：10.18307/2020.0411 |
| 分类号: |
| 基金项目:国家自然科学基金项目（31670473）资助. |
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| Dynamics and driving factors of the river pCO2 in the Three Gorges Reservoir area with urbanization gradients |
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YI Zihan1,2, LI Siyue1, TANG Wei1, LI Yuying3
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1.Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, P. R. China;2.University of Chinese Academy of Sciences, Beijing 100049, P. R. China;3.Collaborative Innovation Center of Water Security for Water Source Region of Middle Route Project of South-North Water Diversion of Henan Province, Nanyang Normal University, Nanyang 473061, P. R. China
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| Abstract: |
| Rivers are considered to be an important source of atmospheric CO2, while the responses of riverine CO2 evasion rate to intensified human activities such as urbanization are poorly understood. The characterization of CO2 partial pressure (pCO2) in three rivers with different urbanization gradients of the Three Gorges Reservoir area was studied. Water sampling was thus carried out in August 2018. pH values and water temperatures were measured in situ using a portable CyberScan PCD 650 multi-parameters system (Eutech, USA), while both the dissolved organic carbon (DOC) and nutrients (DTN-dissolved total nitrogen, DTP-dissolved total phosphorus) were determined in the laboratory. Land use composition was extracted by ArcGIS 10.3. The pCO2 of rivers with different urbanization intensity was calculated by pH, alkalinity and water temperature. Our results indicated that the proportions of urban area are as follows: Ruxi RiverpCO2 were 1790±1210 μatm, 2006±3546 μatm, 4094±4218 μatm respectively. The average pCO2 were much higher than the atmospheric equilibrium,and the studied rivers were therefore characterized as a CO2 source. The concentrations of DOC, DTN and Alk (Alkalinity), EC (Conductivity) were significantly different among rivers. The concentrations of DOC, DTN, DTP and Alk were consistent with the riverine urbanization gradients. We concluded that urbanization could enhance riverine pCO2, and thus potentially increased riverine CO2 evasion. Our results supported the hypothesis that human intensive practices would increase riverine dissolved CO2 and water-air areal flux, which would be helpful for the prediction of riverine CO2 emission under regional and global urbanization. |
| Key words: Urbanization gradient Three Gorges Reservoir area partial pressure of carbon dioxide environmental factors |
