| 三峡库区典型农业小流域水体中溶解性有机质的光谱特征 |
| 摘要点击 3223 全文点击 1536 投稿时间：2015-11-26 修订日期：2016-01-04 |
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| 中文关键词 三峡库区 农业小流域 溶解性有机质 三维荧光光谱 紫外-可见光谱 消落带 |
| 英文关键词 Three Gorges Reservoir areas agricultural small watershed dissolved organic matter(DOM) three- dimensional fluorescence spectrum UV-Vis spectrum water-level fluctuation zone |
| 作者 | 单位 | E-mail | | 王齐磊 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆市农业资源与环境研究重点实验室, 重庆 400716 | beijixuekuaile@163.com | | 江韬 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆市农业资源与环境研究重点实验室, 重庆 400716
Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå
SE-90183, Sweden | Jiangtower666@163.com | | 赵铮 | 贵州省环境监测中心站, 贵阳 550081 | | | 梁俭 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆市农业资源与环境研究重点实验室, 重庆 400716 | | | 木志坚 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆市农业资源与环境研究重点实验室, 重庆 400716 | | | 魏世强 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆市农业资源与环境研究重点实验室, 重庆 400716 | | | 陈雪霜 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆市农业资源与环境研究重点实验室, 重庆 400716 | |
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| 中文摘要 |
| 溶解性有机质(DOM)作为重要的地球化学因子,在流域水体环境中扮演着重要的作用.本研究以三峡库区消落带典型农业小流域--重庆涪陵区王家沟为研究对象,结合该流域内不同土地利用类型,通过紫外-可见光吸收和荧光光谱,对小流域内水体DOM的光谱特征进行了表征和分析.结果表明,该农业小流域水体DOM空间差异较大,其组成和来源均存在明显不同. CDOM在DOM中所占比例[ag*(355)]大小顺序为:稻田水> 沟渠水> 池塘水> 井水> 出口水,其中稻田水和沟渠水的SUVA254较井水和出口水大,芳香性更明显.三维荧光光谱中2类4个荧光峰(A、C和B、T),DOM来源都是内部(微生物、藻类)以及外源(腐殖质)的双重贡献.除自生源微生物活动的影响外,外源生活污水和农业生产用水的影响也是导致DOM组分中类蛋白组分增多的重要原因.对比了不同种植季时相同位置水样DOM光谱特征,类蛋白组分是控制两个种植季水体DOM特征波动的重要因素.土地使用方式变化后水体DOC、CDOM和DOM当中的类蛋白/类腐殖荧光组分[r(T/C)]比例存在明显差异,而FI、BIX和r(A/C)差异不显著. |
| 英文摘要 |
| As a key geochemical factor in earth system, dissolved organic matter (DOM) plays an important role in controlling environmental quality of watersheds. In this study, a typical agricultural watershed of Three Gorges reservoir areas, Wangjiagou watershed in Fuling district of Chongqing, was selected to characterize DOM in waters through fluorescence and UV-Vis spectroscopy, while the effect of land-use types in this watershed was discussed. The results showed large spatial variances of aquatic DOM in this watershed, with significant differences in compositions and sources. After calculation of ag*(355) for indicating proportion of chromophoric DOM in bulk DOM, the order of DOM was paddy rice field> ditch> pond> well> outlet point. DOM samples from paddy rice field and ditch showed higher SUVA254 suggesting higher aromaticity. DOM from this watershed showed 2 typical types (4 peaks A, C, B and T) of fluorescent components including humic-like and protein-like components. Dual contributions from autochthonous (e.g., microbial or alga production) and allochthonous both heavily affected the DOM characteristics. Besides active microbial activities due to high organic and nutrients inputs from agricultures, discharge of sewage and water used in agricultural production could contribute proteins possibly inducing ascending proportion of protein-like component as shown in fluorescence analysis. DOM samples from the same sampling points but in different crop plantation seasons were collected to compare, for understanding the differences between two planting seasons. It clearly suggested protein-like component was the key variable to control the DOM dynamics. After land-use changing from rice/corn into mustard plantation, all of DOC, CDOM and r(T/C)showed significant differences, but no such observations were observed in FI, BIX and r(A/C). |
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