A sprinkling experiment to quantify celerity–velocity differences at the hillslope scale Journal Article uri icon

Overview

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.;

publication date

  • November 27, 2017

Date in CU Experts

  • November 27, 2020 1:18 AM

Full Author List

  • van Verseveld WJ; Barnard HR; Graham CB; McDonnell JJ; Brooks JR; Weiler M

author count

  • 6

Other Profiles

Electronic International Standard Serial Number (EISSN)

  • 1607-7938

Additional Document Info

start page

  • 5891

end page

  • 5910

volume

  • 21

issue

  • 11