Hydrodynamic Processes of Incipient Meander Chute Cutoffs: Laboratory Experiments With Implications for Morphodynamics and Depth‐Averaged Modeling
Abstract Meander chute cutoffs are a common and geomorphically important feature of meandering rivers, exhibiting complex dynamics and distinctive morphologic features. To date, however, the geomorphic processes governing the evolution and formation of these features are poorly understood due to lim...
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Wiley
2025-03-01
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| Series: | Water Resources Research |
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| Online Access: | https://doi.org/10.1029/2024WR038502 |
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| author | Jason T.‐Y. Lin Esteban Lacunza Roberto Fernández Marcelo H. García Bruce Rhoads Jim Best Jessica Z. LeRoy Gary Parker |
| author_facet | Jason T.‐Y. Lin Esteban Lacunza Roberto Fernández Marcelo H. García Bruce Rhoads Jim Best Jessica Z. LeRoy Gary Parker |
| author_sort | Jason T.‐Y. Lin |
| collection | DOAJ |
| description | Abstract Meander chute cutoffs are a common and geomorphically important feature of meandering rivers, exhibiting complex dynamics and distinctive morphologic features. To date, however, the geomorphic processes governing the evolution and formation of these features are poorly understood due to limited knowledge of cutoff hydrodynamics. This paper investigates three‐dimensional mean flow structure, turbulent flow structure, and bed shear stress distribution from high‐resolution flow velocity data in a fixed‐bed, sediment‐free physical model. The results show that (a) the chute channel conveys around 1.4 times the unit‐width flow discharge as the cutoff bend; (b) mean flow structure is highly three‐dimensional, with strong convective acceleration throughout the bends and pronounced flow separation zones in both the chute channel and the cutoff bend; (c) turbulent kinetic energy is intense at shear layers bounding the flow separation zones at several locations in the channel; and (d) bed shear stress is elevated due to strong turbulence in the chute channel and is low in the cutoff bend. The unique hydrodynamics of meander chute cutoffs explains their distinctive morphologic behaviors, including the rapid widening and deepening of chute channels and locations of bars and pools. Moreover, this paper compares quantitatively the depth‐averaged flow structure before and after the cutoff, demonstrating that cross‐sectional redistribution of streamwise momentum by secondary flow remains largely unchanged in the presence of the chute channel. This implies that 2D depth‐averaged hydrodynamic models, parameterized and calibrated for secondary flow in single‐channel meanders, are suitable for simulating flow within chute cutoffs. |
| format | Article |
| id | doaj-art-b9cfa58173f848088859667d49ba3ed2 |
| institution | Kabale University |
| issn | 0043-1397 1944-7973 |
| language | English |
| publishDate | 2025-03-01 |
| publisher | Wiley |
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| series | Water Resources Research |
| spelling | doaj-art-b9cfa58173f848088859667d49ba3ed22025-08-20T03:30:57ZengWileyWater Resources Research0043-13971944-79732025-03-01613n/an/a10.1029/2024WR038502Hydrodynamic Processes of Incipient Meander Chute Cutoffs: Laboratory Experiments With Implications for Morphodynamics and Depth‐Averaged ModelingJason T.‐Y. Lin0Esteban Lacunza1Roberto Fernández2Marcelo H. García3Bruce Rhoads4Jim Best5Jessica Z. LeRoy6Gary Parker7Department of Civil and Environmental Engineering and Ven Te Chow Hydrosystems Laboratory University of Illinois at Urbana‐Champaign Urbana IL USAHydraulics Department Universidad Nacional de La Plata Buenos Aires ArgentinaDepartment of Civil and Environmental Engineering Penn State University University Park PA USADepartment of Civil and Environmental Engineering and Ven Te Chow Hydrosystems Laboratory University of Illinois at Urbana‐Champaign Urbana IL USADepartment of Civil and Environmental Engineering and Ven Te Chow Hydrosystems Laboratory University of Illinois at Urbana‐Champaign Urbana IL USADepartment of Civil and Environmental Engineering and Ven Te Chow Hydrosystems Laboratory University of Illinois at Urbana‐Champaign Urbana IL USADepartment of Geography and Geographic Information Science University of Illinois at Urbana‐Champaign Urbana IL USADepartment of Civil and Environmental Engineering and Ven Te Chow Hydrosystems Laboratory University of Illinois at Urbana‐Champaign Urbana IL USAAbstract Meander chute cutoffs are a common and geomorphically important feature of meandering rivers, exhibiting complex dynamics and distinctive morphologic features. To date, however, the geomorphic processes governing the evolution and formation of these features are poorly understood due to limited knowledge of cutoff hydrodynamics. This paper investigates three‐dimensional mean flow structure, turbulent flow structure, and bed shear stress distribution from high‐resolution flow velocity data in a fixed‐bed, sediment‐free physical model. The results show that (a) the chute channel conveys around 1.4 times the unit‐width flow discharge as the cutoff bend; (b) mean flow structure is highly three‐dimensional, with strong convective acceleration throughout the bends and pronounced flow separation zones in both the chute channel and the cutoff bend; (c) turbulent kinetic energy is intense at shear layers bounding the flow separation zones at several locations in the channel; and (d) bed shear stress is elevated due to strong turbulence in the chute channel and is low in the cutoff bend. The unique hydrodynamics of meander chute cutoffs explains their distinctive morphologic behaviors, including the rapid widening and deepening of chute channels and locations of bars and pools. Moreover, this paper compares quantitatively the depth‐averaged flow structure before and after the cutoff, demonstrating that cross‐sectional redistribution of streamwise momentum by secondary flow remains largely unchanged in the presence of the chute channel. This implies that 2D depth‐averaged hydrodynamic models, parameterized and calibrated for secondary flow in single‐channel meanders, are suitable for simulating flow within chute cutoffs.https://doi.org/10.1029/2024WR038502meander chute cutoffshydrodynamicsmorphodynamicsflow structuresecondary flowdepth‐averaged modeling |
| spellingShingle | Jason T.‐Y. Lin Esteban Lacunza Roberto Fernández Marcelo H. García Bruce Rhoads Jim Best Jessica Z. LeRoy Gary Parker Hydrodynamic Processes of Incipient Meander Chute Cutoffs: Laboratory Experiments With Implications for Morphodynamics and Depth‐Averaged Modeling Water Resources Research meander chute cutoffs hydrodynamics morphodynamics flow structure secondary flow depth‐averaged modeling |
| title | Hydrodynamic Processes of Incipient Meander Chute Cutoffs: Laboratory Experiments With Implications for Morphodynamics and Depth‐Averaged Modeling |
| title_full | Hydrodynamic Processes of Incipient Meander Chute Cutoffs: Laboratory Experiments With Implications for Morphodynamics and Depth‐Averaged Modeling |
| title_fullStr | Hydrodynamic Processes of Incipient Meander Chute Cutoffs: Laboratory Experiments With Implications for Morphodynamics and Depth‐Averaged Modeling |
| title_full_unstemmed | Hydrodynamic Processes of Incipient Meander Chute Cutoffs: Laboratory Experiments With Implications for Morphodynamics and Depth‐Averaged Modeling |
| title_short | Hydrodynamic Processes of Incipient Meander Chute Cutoffs: Laboratory Experiments With Implications for Morphodynamics and Depth‐Averaged Modeling |
| title_sort | hydrodynamic processes of incipient meander chute cutoffs laboratory experiments with implications for morphodynamics and depth averaged modeling |
| topic | meander chute cutoffs hydrodynamics morphodynamics flow structure secondary flow depth‐averaged modeling |
| url | https://doi.org/10.1029/2024WR038502 |
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