A sprinkling experiment to quantify celerity–velocity differences at the hillslope scale
-
Published:2017-11-27
Issue:11
Volume:21
Page:5891-5910
-
ISSN:1607-7938
-
Container-title:Hydrology and Earth System Sciences
-
language:en
-
Short-container-title:Hydrol. Earth Syst. Sci.
Author:
van Verseveld Willem J., Barnard Holly R., Graham Chris B., McDonnell Jeffrey J., Brooks J. RenéeORCID, Weiler MarkusORCID
Abstract
Abstract. Few studies have quantified the differences between celerity and velocity of hillslope water flow and explained the processes that control these differences. Here, we asses these differences by combining a 24-day hillslope sprinkling experiment with a spatially explicit hydrologic model analysis. We focused our work on Watershed 10 at the H. J. Andrews Experimental Forest in western Oregon. Celerities estimated from wetting front arrival times were generally much faster than average vertical velocities of δ2H. In the model analysis, this was consistent with an identifiable effective porosity (fraction of total porosity available for mass transfer) parameter, indicating that subsurface mixing was controlled by an immobile soil fraction, resulting in the attenuation of the δ2H input signal in lateral subsurface flow. In addition to the immobile soil fraction, exfiltrating deep groundwater that mixed with lateral subsurface flow captured at the experimental hillslope trench caused further reduction in the δ2H input signal. Finally, our results suggest that soil depth variability played a significant role in the celerity–velocity responses. Deeper upslope soils damped the δ2H input signal, while a shallow soil near the trench controlled the δ2H peak in lateral subsurface flow response. Simulated exit time and residence time distributions with our hillslope hydrologic model showed that water captured at the trench did not represent the entire modeled hillslope domain; the exit time distribution for lateral subsurface flow captured at the trench showed more early time weighting.
Funder
National Science Foundation
Publisher
Copernicus GmbH
Subject
General Earth and Planetary Sciences,General Engineering,General Environmental Science
Reference68 articles.
1. Anderson, S. P., Dietrich, W. E., Montgomery, D. R., Conrad, M. E., ands Loague, K.: Subsurface flow paths in a steep, unchanneled catchment, Water Resour. Res., 33, 2637–2653, 1997. 2. Barnard, H. R., Graham, C. B., Van Verseveld, W. J., Brooks, J. R., Bond, B. J., and McDonnell, J. J.: Mechanistic assessment of hillslope transpiration controls of diel subsurface flow: a steady-state irrigation approach, Ecohydrology, 3, 133–142, 2010. 3. Bishop, K., Seibert, J., Köhler, S., and Laudon, H.: Resolving the double paradox of rapidly old water with variable responses in runoff chemistry, Hydrol. Process., 18, 185–189, 2004. 4. Bishop, K. H.: Episodic Increases in Stream Acidity, Catchment Flow Pathways and Hydrograph Separation, PhD Thesis, Univ. of Cambridge, Cambridge, 246 pp., 1991. 5. Botter, G., Bertuzzo, E., and Rinaldo, A.: Transport in the hydrologic response: travel time distributions, soil moisture dynamics, and the old water paradox, Water Resour. Res., 46, W03514, https://doi.org/10.1029/2009WR008371, 2010.
Cited by
14 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|