| 桂江流域夏季水-气界面CO2脱气的空间变化及其影响因素 |
| 摘要点击 2506 全文点击 678 投稿时间：2017-01-13 修订日期：2017-02-23 |
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| 中文关键词 CO2脱气 空间变化 碳酸平衡系统 光合作用 桂江流域 |
| 英文关键词 CO2 degassing spatial variation carbonate equilibrium system photosynthesis Guijiang River basin |
| 作者 | 单位 | E-mail | | 张陶 | 西南大学地理科学学院, 重庆 400715
中国地质科学院岩溶地质研究所/国土资源部、广西岩溶动力学重点实验室/联合国教科文组织国际岩溶研究中心, 桂林 541004 | tao21mi@163.com | | 李建鸿 | 中国地质科学院岩溶地质研究所/国土资源部、广西岩溶动力学重点实验室/联合国教科文组织国际岩溶研究中心, 桂林 541004 | | | 蒲俊兵 | 中国地质科学院岩溶地质研究所/国土资源部、广西岩溶动力学重点实验室/联合国教科文组织国际岩溶研究中心, 桂林 541004 | junbingpu@karst.ac.cn | | 吴飞红 | 西南大学地理科学学院, 重庆 400715
中国地质科学院岩溶地质研究所/国土资源部、广西岩溶动力学重点实验室/联合国教科文组织国际岩溶研究中心, 桂林 541004 | | | 李丽 | 西南大学地理科学学院, 重庆 400715
中国地质科学院岩溶地质研究所/国土资源部、广西岩溶动力学重点实验室/联合国教科文组织国际岩溶研究中心, 桂林 541004 | | | 袁道先 | 西南大学地理科学学院, 重庆 400715
中国地质科学院岩溶地质研究所/国土资源部、广西岩溶动力学重点实验室/联合国教科文组织国际岩溶研究中心, 桂林 541004 | |
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| 中文摘要 |
| 河流具有复杂的流域空间异质性，加之岩溶区河流富钙偏碱高溶解无机碳的特殊环境，使得河流水-气界面CO2脱气出现显著的空间变化.为揭示岩溶区河流水-气界面CO2脱气的空间变化特征及其影响因素，利用主要离子、物理化学参数、δ13CDIC等数据以及模型法和浮游箱法分析桂江流域水-气界面CO2脱气特征.结果表明：1桂江流域水文地球化学表现出明显的空间变化特征，HCO3-、Ca2+以及电导率、总溶解性固体（TDS）、SIc、pCO2都表现出中游支流>中游>下游>上游的相似的分布特征；2桂江流域在监测期间均表现出CO2脱气，为大气CO2的源，脱气通量平均值为237 mg·（m2·h）-1，位于世界河流平均CO2脱气通量范围内，但桂江流域CO2脱气在不同的河段表现出明显的空间变化，中游支流和中游明显大于上游和下游；3桂江流域中游干流和支流CO2脱气主要受到碳酸平衡系统的影响，但同时中游支流受到生物光合作用的影响.此外，上游CO2脱气通量主要受到大气环境因素的影响，而下游CO2脱气通量则受到诸多因素的共同影响. |
| 英文摘要 |
| River is characterized by obvious spatial heterogeneity in catchment, which is exacerbated by special environment features of calcium-rich, alkaline and DIC-rich(dissolved inorganic carbon) in karst river. Thus, it also leads to significant spatial variation in the CO2 degassing across water-air interface. Main ions, physicochemical parameters, δ13CDIC value and two common approaches(floating chamber(FC) and thin boundary layer models(TBL) were used to analyze the CO2 degassing characteristics in Guijiang River, a karst river, China. The results were as follows:1 Hydrochemistry in Guijiang River basin showed a significant spatial change. All of HCO3-, Ca2+, specific conductivity, total dissolved solids(TDS), SIc and pCO2 showed similar distribution characteristics in the following order:tributaries in the middle reaches > middle reaches > Downstream > Upstream of Guijiang River. 2 During the monitoring period, CO2 degassing occurred in all the sampling sites and it was the CO2 source for the atmosphere. The mean CO2 evasion was 237 mg·(m2·h)-1 in Guijiang River, which located in the range of average CO2 evasion of global river. However, significant spatial variations also occurred along Guijiang River. The CO2 degassing flux in tributaries of the middle reaches and middle reaches of the mainstream were obviously larger than those in downstream and upstream of the mainstream. 3 CO2 degassing was mainly affected by carbonate equilibrium system in tributaries in the middle reaches and middle reaches in the mainstream of the Guijiang River basin, which resulted in obviously larger CO2 degassing than those in downstream and upstream of mainstream. However, the CO2 degassing flux in tributaries of the middle reaches was also simultaneously affected by biological photosynthesis, and the minimum CO2 degassing flux[6.38 mg·(m2·h)-1] appeared in tributaries of the middle reaches. In addition, the CO2 degassing flux in mainstream upstream was mainly affected by atmospheric environmental factors, while it was synergetically influenced by many factors in mainstream downstream. |
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