Advancing stream classification and hydrologic modeling of ungaged basins for environmental flow management in coastal southern California
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Published:2023-08-22
Issue:16
Volume:27
Page:3021-3039
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ISSN:1607-7938
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Container-title:Hydrology and Earth System Sciences
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language:en
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Short-container-title:Hydrol. Earth Syst. Sci.
Author:
Adams Stephen K.ORCID, Bledsoe Brian P., Stein Eric D.ORCID
Abstract
Abstract. Environmental streamflow management can improve the ecological health of streams by returning modified flows to more natural
conditions. The Ecological Limits of Hydrologic Alteration (ELOHA) framework
for developing regional environmental flow criteria has been implemented to
reverse hydromodification across the heterogenous region of coastal southern California (So. CA) by focusing on two elements of the flow regime:
streamflow permanence and flashiness. Within ELOHA, classification groups
streams by hydrologic and geomorphic similarity to stratify flow–ecology relationships. Analogous grouping techniques are used by hydrologic modelers
to facilitate streamflow prediction in ungaged basins (PUB) through
regionalization. Most watersheds, including those needed for stream
classification and environmental flow development, are ungaged. Furthermore,
So. CA is a highly heterogeneous region spanning gradients of urbanization
and flow permanence, which presents a challenge for regionalizing ungaged
basins. In this study, we develop a novel classification technique for PUB
modeling that uses an inductive approach to group perennial, intermittent,
and ephemeral regional streams by modeled hydrologic similarity followed by
deductively determining class membership with hydrologic model errors and
watershed metrics. As a new type of classification, this hydrologic-model-based classification (HMC) prioritizes modeling accuracy, which in
turn provides a means to improve model predictions in ungaged basins while complementing traditional classifications and improving environmental flow
management. HMC is developed by calibrating a regional catalog of
process-based rainfall–runoff models, quantifying the hydrologic reciprocity of calibrated parameters that would be unknown in ungaged basins and grouping sites according to hydrologic and physical similarity. HMC was
applied to 25 USGS streamflow gages in the “South Coast” region of California and was compared to other hybrid PUB approaches combining inductive and deductive classification. Using an average cluster error metric, results show that HMC provided the most hydrologically similar groups according to
calibrated parameter reciprocity. Hydrologic-model-based classification is relatively complex and time-consuming to implement, but it shows potential
for simplifying ungaged basin management. This study demonstrates the
benefits of thorough stream classification using multiple approaches and suggests that hydrologic-model-based classification has advantages for PUB and building the hydrologic foundation for environmental flow management.
Funder
California State Water Resources Control Board
Publisher
Copernicus GmbH
Subject
General Earth and Planetary Sciences,General Engineering,General Environmental Science
Reference80 articles.
1. Abdulla, F. A. and Lettenmaier, D. P.: Development of regional parameter
esimtaiton equations for a macroscale hydrologic model, J. Hydrol., 197,
230–257, https://doi.org/10.1016/S0022-1694(96)03262-3, 1997. 2. Arizona Department of Transportation (ADOT): Highway Drainage Design Manual,
Volume 2: Hydrology, Phoenix, AZ, 182 pp., https://azdot.gov/sites/default/files/2019/07/2014_adot_hydrology_manual.pdf (last access: 21 March 2021), 2014. 3. Arsenault, R., Breton-Dufour, M., Poulin, A., Dallaire, G., and
Romero-Lopez, R.: Streamflow prediction in ungauged basins: analysis of
regionaliztaion methods in a hydrologically heterogeneous region of Mexico,
Hydrolog. Sci. J., 64, 1297–1311, https://doi.org/10.1080/02626667.2019.1639716, 2019. 4. Arthington, A. H., Bunn, S. E., Poff, N. L., and Naiman, R. J.: The Challenge of
Providing Environmental Flow Rules to Sustain River Ecosystems, Ecol. Appl.,
16, 1311–1318,
https://doi.org/10.1890/1051-0761(2006)016[1311:TCOPEF]2.0.CO;2, 2006. 5. Baker, D. B., Richards, R. P., Loftus, T. T., and Kramer, J. W.: A New
Flashiness Index: Characteristics and Applications to Midwestern Reivers and
Streams, J. Am. Water Resour. As., 40, 503–522, https://doi.org/10.1111/j.1752-1688.2004.tb01046.x, 2004.
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