Response of dissolved organic matter optical properties to net inflow runoff in a large fluvial plain lake and the connecting channels
Response of dissolved organic matter optical properties to net inflow runoff in a large fluvial plain lake and the connecting channels
复制标题
大型河流平原湖泊及其连接河道溶解有机物光学特性对净流入径流的响应
DOI：
10.1016/j.scitotenv.2018.05.180
复制
发表时间：
2018
影响因子：
9.8
通讯作者：
Jeppesen Erik
中科院分区：
文献类型：
--
作者：
Zhou Yongqiang;Yao Xiaolong;Zhang Yunlin;Zhang Yibo;Shi Kun;Tang Xiangming;Qin Boqiang;Podgorski David C.;Brookes Justin D.;Jeppesen Erik
河流平原湖泊流域通常高度城市化，并有高浓度的发色溶解有机物（CDOM）。CDOM来自连接城市渠道通常共享强大的陆地和人为信号和净流入径流（Qnet）的湖泊作为居民家庭污水输入的代理。本文研究了太湖及其连接河道中CDOM的光学特性与Qnet的关系。CDOM吸收系数a（350）、溶解有机碳（DOC）、C1-C7的荧光强度（Fmax）和δ 15 N-TDN在西北部湖区相对较高，而δ 13 C-DOM的吸收系数a（250）/a（365）、光谱斜率S（275 -295）和δ 13 C-DOM在西北部湖区相对较低，均显示了较强的陆源和人为影响。相反，城市土地覆盖（%城市），国内生产总值（GDP）和人口密度相对较低的西部子流域和高东部子流域。这种明显的矛盾反映了不同子流域的Qnet的变化。各子流域的Qnetanda（350）、DOC、化学需氧量（COD）、叶绿素a（Chl-a）、C1-C3和C6-C7的Fmax以及%C2-%C3之间均存在显著的正相关关系。结果表明，平均a（350）、DOC、COD、Chl-a、C1-C3和C6、%C2-%C3与Qnet× %城市、Qnet× GDP、Qnet×人口密度的乘积均呈显著正相关。我们进一步发现，木质素的主要贡献的总数量分配公式的样品收集的渠道在湖西流域和中央湖使用高分辨率质谱。我们得出结论，Qnetis的CDOM分子的光学性质在太湖的各个区域和连接通道的关键重要性。
Fluvial plain lake watersheds are usually highly urbanized and have high concentrations of chromophoric dissolved organic matter (CDOM). CDOM derived from the connecting urban channels usually share strong terrestrial and anthropogenic signals and net inflow runoff (Qnet) to the lake serves as a proxy of residential household sewage input. We investigate how Qnetcontrols the optical characteristics of CDOM in fluvial plain Lake Taihu and the connecting channels. CDOM absorption coefficienta(350), dissolved organic carbon (DOC), the fluorescence intensity (Fmax) of seven PARAFAC components C1-C7, and δ15N-TDN were higher in the northwestern relative to the other lake regions, anda(250)/a(365), spectral slopeS275–295, and δ13C-DOM relative low in the northwestern lake, all indicating strong terrestrial and anthropogenic effects. Conversely, the urban land cover (%Cities), gross domestic product (GDP), and population density were relatively low in the western sub-watersheds and high in the eastern sub-watersheds. This apparent paradox reflects variations in Qnetfrom different sub-watersheds. Thus, significant positive relationships were found between Qnetanda(350), DOC, chemical oxygen demand (COD), chlorophyll-a(Chl-a), Fmaxof C1-C3 and C6-C7, and %C2-%C3 in the five hydraulic sub-watersheds. We revealed significant positive relationships between meana(350), DOC, COD, Chl-a, C1-C3 and C6, %C2-%C3, and the products of Qnet× %Cities, Qnet× GDP, and Qnet× population density. We further found dominant contribution of lignin to the total number of assigned formulas for the samples collected from the channels in the Huxi watershed and the central lake using high resolution mass spectroscopy. We conclude that Qnetis of key importance for the optical properties of CDOM molecules in the various regions of Lake Taihu and the connecting channels.