Modelling landscape controls on dissolved organic carbon sources and fluxes to streams
Modelling landscape controls on dissolved organic carbon sources and fluxes to streams
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DOI：
10.1007/s10533-014-0046-3
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发表时间：
2015-02
期刊：
影响因子：
4
通讯作者：
J. Dick;D. Tetzlaff;C. Birkel;C. Soulsby
中科院分区：
文献类型：
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作者：
J. Dick;D. Tetzlaff;C. Birkel;C. Soulsby
流域溶解有机碳（DOC）通量受复杂的相互作用，控制生态地球化学过程产生DOC和水文连通性，促进运输通过景观流。本文介绍了一个耦合的水文-生态地球化学模型的开发与有机质丰富的土壤北方流域，模拟每日DOC浓度。简约的模型设计允许DOC通量的相对重要性，从主要景观单元（如山坡，地下水和河岸饱和区）被确定。动态范围的饱和河岸带，其中在最大湿度的排水面积的40%，贡献了84%的DOC流，其中16%来自山坡土壤。这表明河岸对河流水化学的不成比例的影响和水文连通性的非线性的重要性。每个景观单元的时间连通性取决于前期的水分条件，与山坡和谷底饱和区，这是完全断开在最干燥的时期，高度瞬态之间的连接。地下水的贡献保持不变，但其相对重要性在最干旱时期有所增加。这项研究强调了概念化水文连通性及其与水文气候因素的关系的重要性，以及土壤地球化学过程，当模拟溪流DOC。
Catchment dissolved organic carbon (DOC) fluxes are governed by complex interactions, which control biogeochemical processes generating DOC and hydrological connectivity, facilitating transport through the landscape to streams. This paper presents the development of a coupled hydrological-biogeochemical model for a northern watershed with organic-rich soils, to simulate daily DOC concentrations. The parsimonious model design allows the relative importance of DOC fluxes from the major landscape units (e.g. hillslopes, groundwater and riparian saturation area) to be determined. The dynamic extent of the saturated riparian zone, which at maximum wetness comprised 40 % of the drainage area, contributed 84 % of DOC to the stream, of which 16 % was derived from the hillslope soils. This shows the disproportional riparian influence on stream water chemistry and the importance of the non-linearity in hydrological connectivity. The temporal connectivity of each of the landscape units was dependent on antecedent moisture conditions, with highly transient connections between the hillslope and valley bottom saturated area, which were entirely disconnected during the driest periods. The groundwater contribution remained constant, but its relative importance increased during the driest periods. The study emphasises the importance of conceptualising hydrological connectivity and its relation to hydroclimatic factors, as well soil biogeochemical processes, when modelling stream water DOC.