River Mixing in the Amazon as a Driver of Concentration‐Discharge Relationships
River Mixing in the Amazon as a Driver of Concentration‐Discharge Relationships
复制标题
亚马逊河流混合是浓度-排放关系的驱动因素
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
R. Pombosa
中科院分区：
文献类型：
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作者：
J. Bouchez;J. Moquet;J. Espinoza;Jean;J. Guyot;C. Lagane;N. Filizola;Luis Noriega;Liz Hidalgo Sanchez;R. Pombosa
大型水文系统聚集了来自各种途径的成分不同的沃茨。在大陆尺度的河流中，这种聚集明显地发生在支流之间的汇流处。在这里，我们探讨了这种聚集如何影响溶质浓度-排放（C-Q）关系，从而掩盖了这些关系所携带的信息，在风化的关键区的属性。我们建立了一个简单的支流混合模型来预测聚集过程中C-Q关系的行为。我们测试了一组预测的背景下，世界上最大的河流，亚马逊河。特别是，我们预测的C-Q关系的河流排水异质集水区应该是最“稀释”，并应显示最广泛的滞后回线。为了检验这些预测，我们计算了10天周期的时间序列的Q和主要溶质（Si，Ca 2+，Mg 2+，K+，Na+，Cl-，SO 42 −）C和通量（F）位于整个亚马逊流域的13个计量站。与模型预测一致，大多数溶质的C-Q关系从安第斯山前和纯低地地区的相当“化学稳定”的行为（几乎恒定的C）转变为朝向系统口的更多“稀释”模式（负C-Q关系）。在最下游的站点也观察到更突出的C-Q滞后回线。总而言之，这项研究表明，不同流路之间的水和溶质的混合对大尺度水文系统的C-Q关系施加了强有力的控制。
Large hydrological systems aggregate compositionally different waters derived from a variety of pathways. In the case of continental‐scale rivers, such aggregation occurs noticeably at confluences between tributaries. Here we explore how such aggregation can affect solute concentration‐discharge (C‐Q) relationships and thus obscure the message carried by these relationships in terms of weathering properties of the Critical Zone. We build up a simple model for tributary mixing to predict the behavior of C‐Q relationships during aggregation. We test a set of predictions made in the context of the largest world's river, the Amazon. In particular, we predict that the C‐Q relationships of the rivers draining heterogeneous catchments should be the most “dilutional” and should display the widest hysteresis loops. To check these predictions, we compute 10 day‐periodicity time series of Q and major solute (Si, Ca2+, Mg2+, K+, Na+, Cl‐, SO42− ) C and fluxes (F) for 13 gauging stations located throughout the Amazon basin. In agreement with the model predictions, C‐Q relationships of most solutes shift from a fairly “chemostatic” behavior (nearly constant C) at the Andean mountain front and in pure lowland areas, to more “dilutional” patterns (negative C‐Q relationship) toward the system mouth. More prominent C‐Q hysteresis loops are also observed at the most downstream stations. Altogether, this study suggests that mixing of water and solutes between different flowpaths exerts a strong control on C‐Q relationships of large‐scale hydrological systems.
影响因子：
5.3
作者：
Calmels, Damien;Galy, Albert;Chapman, Hazel
通讯作者：
Chapman, Hazel