Impacts of Emergent Vegetation on Hyporheic Exchange
Journal
Geophysical Research Letters
Journal Volume
49
Journal Issue
13
Start Page
e2022GL099095
ISSN
00948276
Date Issued
2022-07-16
Author(s)
Yang, J. Q.
Abstract
Hyporheic exchange, or the exchange of water and solutes between surface and subsurface water at the sediment-water interface, regulates water quality and biogeochemical cycle in aquatic ecosystems. Vegetation, which is ubiquitous in nature, is known to impact hyporheic exchange; yet how vegetation impacts hyporheic exchange remains to be characterized. Here, we show that at the same spatially and temporally-averaged flow velocity (Formula presented.), vegetation increases the rate of hyporheic exchange by a factor of four. By tracking the movement of fluorescent dye in a flume with the refractive-index-matched sediment and translucent vegetation dowels, we demonstrate that the vegetation-induced hyporheic exchange can be characterized by an effective hyporheic exchange velocity, (Formula presented.). We further demonstrate that (Formula presented.) correlates with the total near-bed turbulent kinetic energy (Formula presented.) rather than (Formula presented.), when (Formula presented.), indicating that turbulent kinetic energy is a better metric than flow velocity for predicting hyporheic exchange in regions with vegetation.
Subjects
hyporheic flow
spatial heterogeneity
streams
turbulence
turbulent kinetic energy
vegetation
SDGs
Publisher
John Wiley and Sons Inc
Type
journal article