| 查干湖和新立城水库秋季水体悬浮颗粒物和CDOM吸收特性 |
| 摘要点击 2600 全文点击 1166 投稿时间：2015-04-24 修订日期：2015-08-20 |
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| 中文关键词 吸收特性 有色可溶性有机物 非藻类颗粒物 浮游植物 查干湖 新立城水库 |
| 英文关键词 absorption characteristics CDOM nonalgal particles phytoplankton Chagan Lake Xinlicheng Reservoir |
| 作者 | 单位 | E-mail | | 李思佳 | 中国科学院东北地理与农业生态研究所, 湿地生态与环境重点实验室, 长春 130102
东北师范大学环境学院, 自然灾害研究所, 长春 130024 | jlsdlsj@126.com | | 宋开山 | 中国科学院东北地理与农业生态研究所, 湿地生态与环境重点实验室, 长春 130102 | songks@iga.ac.cn | | 赵莹 | 中国科学院东北地理与农业生态研究所, 湿地生态与环境重点实验室, 长春 130102 | | | 穆光熠 | 中国科学院东北地理与农业生态研究所, 湿地生态与环境重点实验室, 长春 130102
东北师范大学生命科学学院, 草地研究所, 长春 130024 | | | 邵田田 | 中国科学院东北地理与农业生态研究所, 湿地生态与环境重点实验室, 长春 130102 | | | 马建行 | 中国科学院东北地理与农业生态研究所, 湿地生态与环境重点实验室, 长春 130102 | |
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| 中文摘要 |
| 分别于2012年9月对不同盐度水体的查干湖和新立城水进行水体野外采样和室内实验分析,通过测定颗粒物、CDOM等光学活性物质的吸收系数来对比分析两种水体的光学活性物质的吸收特性、来源及其在400~700 nm范围内对总吸收系数的贡献. 结果表明,综合营养状态评价指数显示秋季查干湖、新立城水库水体属于中等富营养化,总悬浮颗粒物的吸收光谱表现均与色素类颗粒物吸收光谱相似. 对于盐度较大的查干湖水体(EC=988.87 μS ·cm-1),非藻类颗粒物占主导地位,各组分贡献率为非藻类颗粒物 > 色素颗粒物 > CDOM; 而盐度较低的新立城水库水体(EC=311.67 μS ·cm-1),色素颗粒物贡献率略大于非藻类颗粒物贡献,各组分贡献率依次为:色素颗粒物 > 非藻类颗粒物 > CDOM. 查干湖总悬浮颗粒物吸收系数ap(440)、ap(675)和非藻类颗粒物吸收系数ad(440)分别与TSM(总悬浮颗粒物)、ISM(无机悬浮颗粒物)和OSM(有机悬浮颗粒物)、Chl-a(叶绿素a)相关性均较好,相关系数在0.55以上; 新立城水库ap(440)、ap(675)与Chl-a相关性较好(0.77和0.85, P < 0.05),ad(440)与ISM具有相关性(0.74, P < 0.01),与OSM表现为负相关(-0.63, P < 0.05). 查干湖CDOM吸收系数ag(440)仅与OSM表现为负相关性(-0.54, P < 0.05),而新立城水库ag(440)与其他参数均无相关性. 通过对CDOM吸收曲线在250~400 nm的拟合所得到的Sg以及相对分子量Mr发现,查干湖的Sg [(0.021±0.001) m-1]大于新立城的Sg[(0.0176±0.001) m-1],而CDOM的相对分子量Mr值分别为11.44±2.00(7.5~15.09)、7.53±0.79(6.17~8.89),查干湖Mr值高于新立城水库水体,表明查干湖CDOM组成较新立城水体中CDOM的分子量小,组成更趋向于小分子. 查干湖受风速和湖岸坍塌的影响产生矿物悬浮、沉积微粒,水体颗粒物以非藻类为主,部分来自于浮游植物降解产物; 新立城水库水体不仅有径流携带的陆源性无机物的输入,同时水体浮游植物生长减弱且微生物分解活动加强,降解有机颗粒物与非藻类吸收系数呈现负相关. |
| 英文摘要 |
| Field surveys and laboratory analysis were carried out in Chagan Lake and Xinlicheng Reservoir under different salinity conditions in September 2012. In the laboratory, the absorption coefficients of particulates and chromophoric dissolved organic matter (CDOM) were measured, aiming to compare the absorption features, source of optical active substances and relative contribution of optical active constituents over the range of PAR (400-700 nm) in Chagan Lake and Xinlicheng Reservoir. The results showed that the Chagan Lake and Xinlicheng Reservoir were water bodies with medium eutrophication in autumn by TAL nutrient index and the absorption spectra of particulates matters were similar to those of phytoplankton. For the Chagan Lake with high salinity(EC=988.87 μS ·cm-1), the total particulate absorption was dominated by the nonalgal particles, and the contribution rate was in the order of nonalgal particles > phytoplankton > CDOM. For the Xinlicheng Reservoir with low salinity(EC=311.67 μS ·cm-1), the total particulate absorption was dominated by the phytoplankton, and the contribution rate was ranked as phytoplankton > nonalgal particles > CDOM. Positive correlation was observed between ap(440), ap(675),ad(440) and total suspended matter (TSM), inorganic suspended matter (ISM), organic suspended matter (OSM) and Chl-a respectively in Chagan Lake, with correlation coefficients all above 0.55. Positive correlation was observed between ap(440), ap(675) and Chl-a (0.77 and 0.85, P < 0.05), so did ad(440) and ISM(0.74, P < 0.01), while negative correlation was observed between ad(440) and OSM in the Xinlicheng Reservoir. In terms of Chagan Lake, negative correlation was merely observed between ag(440) and OSM (-0.54, P < 0.05), but not in the Xinlicheng Reservoir. Both Sg, which was calculated by the fitting absorption curve from 250 to 400 nm, and relative molecular weight M showed that Sg [(0.021±0.001) m-1] in Chagan Lake was greater than that in the Xinlicheng Reservoir [(0.0176±0.001) m-1], and Mr in Chagan Lake was 11.44±2.00(7.5-15.09), which was greater than that in Xinlicheng Reservoir 7.53±0.79(6.17-8.89), indicating that the relative molecular weight of CDOM in the Chagan Lake was less than that in the Xinlicheng Reservoir. The Chagan Lake was greatly affected by wind speed and shore collapse to produce suspended mineral and sediment particles. Thereby the total particulate absorption was dominated by the nonalgal particles. The waters in the Xinlicheng Reservoir were greatly impacted by terrestrial inorganic matter, and the growth of phytoplankton was weakened and microbes activities were strengthened simultaneously, which led to the negative correlations between ag(λ) and OSM. |
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