Journal article
Dynamic Hyporheic Zones: Exploring the Role of Peak Flow Events on Bedform-Induced Hyporheic Exchange
Water resources research, Vol.55(1), pp.218-235
01/01/2019
DOI: 10.1029/2018WR022993
Abstract
Discharge varies in space and time, driving hyporheic exchange processes in river corridors that affect biogeochemical cycling and ultimately control the dynamics of biogeochemical hot spots and hot moments. Herein, we use a reduced-order model to conduct the systematic analysis of the interplay between discharge variability (peak flow intensities, duration, and skewness) and streambed topography (bedform aspect ratios and channel slopes) and their role in the flow and transport characteristics of hyporheic zones (HZs). We use a simple and robust conceptualization of single peak flow events for a series of periodic sinusoidal bedforms. Using the model, we estimate the spatial extent of the HZ, the total amount of exchange, and the residence time of water and solutes within the reactive environment and its duration relative to typical time scales for oxygen consumption (i.e., a measure of the denitrification potential). Our results demonstrate that HZ expansion and contraction is controlled by events yet modulated by ambient groundwater flow. Even though the change in hyporheic exchange flux (%) relative to baseflow conditions is invariant for different values of channel slopes, absolute magnitudes varied substantially. Primarily, peak flow events cause more discharge of older water for the higher aspect ratios (i.e., for dunes and ripples) and lower channel slopes. Variations in residence times during peak flow events lead to the development of larger areas of potential nitrification and denitrification in the HZ for longer durations. These findings have potential implications for river management and restoration, particularly the need for (re)consideration of the importance of hyporheic exchange under dynamic flow conditions.
Details
- Title: Subtitle
- Dynamic Hyporheic Zones: Exploring the Role of Peak Flow Events on Bedform-Induced Hyporheic Exchange
- Creators
- Tanu Singh - University of BirminghamLiwen Wu - Leibniz Institute of Freshwater Ecology and Inland FisheriesJesus D. Gomez-Velez - Vanderbilt UniversityJörg Lewandowski - Leibniz Institute of Freshwater Ecology and Inland FisheriesDavid M. Hannah - University of BirminghamStefan Krause - University of Birmingham
- Resource Type
- Journal article
- Publication Details
- Water resources research, Vol.55(1), pp.218-235
- DOI
- 10.1029/2018WR022993
- ISSN
- 0043-1397
- eISSN
- 1944-7973
- Number of pages
- 18
- Grant note
- Biological and Environmental Research (http://data.elsevier.com/vocabulary/SciValFunders/100006206) Horizon 2020 (http://data.elsevier.com/vocabulary/SciValFunders/501100007601) U.S. Department of Energy (http://data.elsevier.com/vocabulary/SciValFunders/100000015) Neurosciences Foundation (http://data.elsevier.com/vocabulary/SciValFunders/501100020414) Pacific Northwest National Laboratory (http://data.elsevier.com/vocabulary/SciValFunders/100011661) U.S. Geological Survey (http://data.elsevier.com/vocabulary/SciValFunders/100000203) River Corridor Powell Center Stephen F. Austin State University (http://data.elsevier.com/vocabulary/SciValFunders/100007704) SBR Scientific Focus Area University of Birmingham (http://data.elsevier.com/vocabulary/SciValFunders/501100000855)
- Language
- English
- Date published
- 01/01/2019
- Academic Unit
- Civil and Environmental Engineering
- Record Identifier
- 9984962630102771
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