| 岩溶地表河旱季有色溶解有机质组成及来源:以金佛山碧潭河为例 |
| 摘要点击 2197 全文点击 758 投稿时间：2017-11-12 修订日期：2017-12-14 |
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| 中文关键词 岩溶地表河 有色溶解有机质(CDOM) 三维荧光光谱 平行因子分析 紫外-可见吸收光谱 岩溶水化学 碧潭河 |
| 英文关键词 karst surface river chromophoric dissolved organic matter(CDOM) EEMs PARAFAC UV-visible absorption spectrum karst hydrochemistry characteristics Bitan River |
| 作者 | 单位 | E-mail | | 刘跃 | 西南大学地理科学学院, 岩溶环境重庆市重点实验室, 重庆 400715 | 18716638665@163.com | | 贺秋芳 | 西南大学地理科学学院, 岩溶环境重庆市重点实验室, 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, 桂林 541004 | hqfeddy@swu.edu.cn | | 刘宁坤 | 西南大学地理科学学院, 岩溶环境重庆市重点实验室, 重庆 400715 | | | 刘九缠 | 西南大学地理科学学院, 岩溶环境重庆市重点实验室, 重庆 400715 | | | 王正雄 | 西南大学地理科学学院, 岩溶环境重庆市重点实验室, 重庆 400715 | | | 段世辉 | 西南大学地理科学学院, 岩溶环境重庆市重点实验室, 重庆 400715 | |
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| 中文摘要 |
| 岩溶水体中的有机碳汇是岩溶碳汇的重要组成部分，为探明地处亚热带的岩溶地表河——碧潭河水体CDOM的组成及来源，于2017年1~3月开展从上游至下游9个点位的调查，利用三维荧光光谱结合紫外-可见吸收光谱以及常规水化学指标，分析碧潭河CDOM组成和来源及其影响因素.结果表明：①碧潭河水体中HCO3-的质量分数>70%、Ca2++Mg2+的质量分数>80%，为主要阴阳离子，水化学性质主要受岩石风化作用的影响；②水体CDOM在旱季主要由类腐殖酸（C1）、类富里酸（C2）和类酪氨酸（C3）组成，FI、BIX、HIX以及β：α的平均值分别为2.06、0.87、4.35和0.69，较高的FI、BIX、β∶α以及较低的HIX显示碧潭河水体CDOM在旱季整体而言具有较强的自生源特征；③水体中DIC质量浓度与C2、C3荧光强度得分的相关性系数分别为0.515（P<0.05）和0.644（P<0.01），表明水生生物光合作用固定DIC对水体中CDOM的形成起到重要作用，该过程是对岩石风化碳汇的转换和稳定. |
| 英文摘要 |
| Since resistant dissolved organic matter (RDOM) plays a critically important role in a karst carbon sink, one of the most important continental carbon sinks, research focusing on the origination, transportation, and translation of RDOM in a karst water system is important. Currently, 3D-fluorescence EEMs are used to detect the composition and origination of chromophoric dissolved organic matter (CDOM), an important part of RDOM. This is a very fast and efficient method for CDOM analysis. In this study, 3D-fluorencence EEMs combined with UV-visible absorption spectrum were used to analyze the composition and origination of CDOM in the Bitan River at Jinfo Mountain. Samples were collected from nine sampling sites from January to March 2017 and analyzed with CDOM EEMs and UV-visible absorption spectrums. In addition hydrochemical characteristics were determined and then samples were stimulated with PARAFAC to detect the chromophoric fluorescent groups and indexes. The PARAFAC stimulation revealed three chromophoric fluorescent groups in which fulvic acid was the largest component, accounting for about 44%, with a humic acid content of about 32% and tyrosine-like acid content of about 24%. Four indexes: FI, BIX, HIX, and β∶α, were calculated, and the mean values were 2.06, 0.87, 4.35 and 0.69, which showed relatively high FI, BIX, and β∶α values and a low HIX value, implying that the CDOM was autochthonous and originated from microbes and aquatic plants in the dry season. The spatial dynamic of the index revealed an increased BIX and decreased HIX from the upstream area to the downstream area, implying the impact of land-use and human activities. The forest soil input more humic acid and agriculture input more N and P resulting in flourishing aquatic plants and microbes. Moreover, the correlation coefficients of DIC and humic acid, tyrosine-like acid were 0.515 (P<0.05) and 0.644 (P<0.01), from which it could be inferred that DIC contributed to CDOM formation. The conclusions of this study revealed that DIC would be fixed by karst water aquatic plants and microbes and then sink as autochthonous CDOM and become part of karst water carbon sink. |
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