Interactions and connectivity between runoff generation processes of different spatial scales
Interactions and connectivity between runoff generation processes of different spatial scales
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不同空间尺度径流生成过程之间的相互作用和连通性
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
M. Weiler
中科院分区：
文献类型：
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作者：
S. Bachmair;M. Weiler
在野外监测产流过程是发展概念水文模型和理论的先决条件。同时，我们对水文过程的感知在很大程度上取决于观测的时空尺度。因此，本研究的目的是探讨不同空间尺度（地块尺度、山坡尺度和水源尺度）产流过程之间的相互作用。在地形、地质和土壤性质相似，但植被覆盖（草地、针叶林和混交林）不同的3个小v形源头坡地上，测量了不同的产流过程：高时空分辨率井的地下水位动态、坡地底部3个10 m宽沟槽（每个沟槽分为2个沟槽段）的地下流（SSF）、地块尺度上的地面流和集水区径流。bachmaair等（）发现地块尺度下的地下水位动态具有较高的空间变异性。在本研究中，我们研究了样地尺度与坡面尺度观测的代表性，以及坡面动态（SSF和坡面流）与径流之间的联系。每10 m宽海沟内总SSF的显著差异证实了地下水位动态的高空间变异性。坡面尺度SSF的样地尺度观测的代表性很大程度上取决于井是否捕捉到空间可变的流动路径。在草地山坡上，地下流动路径没有被我们相对密集的间隔井（3米）捕获，尽管与针叶林山坡有类似的沟槽流动响应。关于山坡动态与流域径流之间的联系，我们发现河流流量与山坡水文动力学（沟流和坡面流）之间存在中等到高度的相关性，这凸显了山坡过程在这个小流域中的重要性。虽然SSF对总事件集水区径流的贡献很小，但在洪峰期的贡献是中等到较大的。此外，在不同尺度上空间不连续的测量点之间存在过程同步性，这可能表明地下流道的连通性。我们的研究结果强调，在设计监测网络和评估水文连通性时，需要(i)结合不同空间尺度的观测结果，以及（ii）考虑地块和山坡尺度上SSF的高空间变异性。版权所有©2013 John Wiley & Sons， Ltd
Monitoring runoff generation processes in the field is a prerequisite for developing conceptual hydrological models and theories. At the same time, our perception of hydrological processes strongly depends on the spatial and temporal scale of observation. Therefore, the aim of this study is to investigate interactions between runoff generation processes of different spatial scales (plot scale, hillslope scale, and headwater scale). Different runoff generation processes of three hillslopes with similar topography, geology and soil properties, but differences in vegetation cover (grassland, coniferous forest, and mixed forest) within a small v‐shaped headwater were measured: water table dynamics in wells with high spatial and temporal resolution, subsurface flow (SSF) of three 10 m wide trenches at the bottom of the hillslopes subdivided into two trench sections each, overland flow at the plot scale, and catchment runoff. Bachmair et al. ( ) found a high spatial variability of water table dynamics at the plot scale. In this study, we investigate the representativity of SSF observations at the plot scale versus the hillslope scale and vice versa, and the linkage between hillslope dynamics (SSF and overland flow) and streamflow. Distinct differences in total SSF within each 10 m wide trench confirm the high spatial variability of the water table dynamics. The representativity of plot scale observations for hillslope scale SSF strongly depends on whether or not wells capture spatially variable flowpaths. At the grassland hillslope, subsurface flowpaths are not captured by our relatively densely spaced wells (3 m), despite a similar trench flow response to the coniferous forest hillslope. Regarding the linkage between hillslope dynamics and catchment runoff, we found an intermediate to high correlation between streamflow and hillslope hydrological dynamics (trench flow and overland flow), which highlights the importance of hillslope processes in this small watershed. Although the total contribution of SSF to total event catchment runoff is rather small, the contribution during peak flow is moderate to substantial. Additionally, there is process synchronicity between spatially discontiguous measurement points across scales, potentially indicating subsurface flowpath connectivity. Our findings stress the need for (i) a combination of observations at different spatial scales, and (ii) a consideration of the high spatial variability of SSF at the plot and hillslope scale when designing monitoring networks and assessing hydrological connectivity. Copyright © 2013 John Wiley & Sons, Ltd.