Journal article
Impact of Dynamically Changing Discharge on Hyporheic Exchange Processes Under Gaining and Losing Groundwater Conditions
Water resources research, Vol.54(12), pp.10,076-10,093
12/2018
DOI: 10.1029/2018WR023185
Abstract
Channel discharge, geomorphological setting, and regional groundwater flow determine the spatiotemporal variability of bedform-induced hyporheic exchange and the emergence of biogeochemical hot spots and hot moments that it drives. Of particular interest, and significantly understudied, is the role that dynamically changing discharge has on the hyporheic exchange process and how regional groundwater flow modulates the effects of transience. In this study, we use a reduced-complexity model to systematically explore the bedform-induced hyporheic responses to dynamically changing discharge events in systems with different bedform geometries exposed to varying degrees of groundwater flow (under both upwelling and downwelling conditions). With this in mind, we define metrics to quantify the effects of transience: spatial extent of the hyporheic zone, net hyporheic flux, mean residence time, and denitrification efficiency. We find that regional groundwater flow and geomorphological settings greatly modulate the temporal evolution of bedform-induced hyporheic responses driven by a single-peak discharge event. Effects of transience diminish with increasing groundwater upwelling or downwelling fluxes, decreasing bedform aspect ratios, and decreasing channel slopes. Additionally, we notice that increasing discharge intensities can reduce the modulating impacts of regional groundwater flow on the effects of transience but hardly overcomes the geomorphological controls. These findings highlight the necessities of evaluating hyporheic exchange processes in a more comprehensive framework.
Details
- Title: Subtitle
- Impact of Dynamically Changing Discharge on Hyporheic Exchange Processes Under Gaining and Losing Groundwater Conditions
- Creators
- Liwen Wu - Leibniz Institute of Freshwater Ecology and Inland FisheriesTanu Singh - University of BirminghamJesus Gomez-Velez - Vanderbilt UniversityGunnar Nützmann - Humboldt-Universität zu BerlinAnders Wörman - KTH Royal Institute of TechnologyStefan Krause - University of BirminghamJörg Lewandowski - Leibniz Institute of Freshwater Ecology and Inland Fisheries
- Resource Type
- Journal article
- Publication Details
- Water resources research, Vol.54(12), pp.10,076-10,093
- DOI
- 10.1029/2018WR023185
- ISSN
- 0043-1397
- eISSN
- 1944-7973
- Grant note
- U.S. Department of Energy (http://data.elsevier.com/vocabulary/SciValFunders/100000015) Horizon 2020 Framework Programme (http://data.elsevier.com/vocabulary/SciValFunders/100010661) Pacific Northwest National Laboratory (http://data.elsevier.com/vocabulary/SciValFunders/100011661) U.S. Geological Survey (http://data.elsevier.com/vocabulary/SciValFunders/100000203) Biological and Environmental Research (http://data.elsevier.com/vocabulary/SciValFunders/100006206) Leibniz-Institut für Gewässerökologie und Binnenfischerei (http://data.elsevier.com/vocabulary/SciValFunders/501100013656) GRK 2032/1 / Deutsche Forschungsgemeinschaft (501100001659) SBR Scientific Focus Area 641939 / H2020 Marie Skłodowska-Curie Actions (http://data.elsevier.com/vocabulary/SciValFunders/100010665) Horizon 2020 (http://data.elsevier.com/vocabulary/SciValFunders/501100007601)
- Language
- English
- Date published
- 12/2018
- Academic Unit
- Civil and Environmental Engineering
- Record Identifier
- 9984962625902771
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