Hydrodynamic Processes of Incipient Meander Chute Cutoffs: Laboratory Experiments With Implications for Morphodynamics and Depth‐Averaged Modeling

Water Resources Research, Journal Year: 2025, Volume and Issue: 61(3)

Published: March 1, 2025

Abstract Meander chute cutoffs are a common and geomorphically important feature of meandering rivers, exhibiting complex dynamics distinctive morphologic features. To date, however, the geomorphic processes governing evolution formation these features poorly understood due to limited knowledge cutoff hydrodynamics. This paper investigates three‐dimensional mean flow structure, turbulent bed shear stress distribution from high‐resolution velocity data in fixed‐bed, sediment‐free physical model. The results show that (a) channel conveys around 1.4 times unit‐width discharge as bend; (b) structure is highly three‐dimensional, with strong convective acceleration throughout bends pronounced separation zones both (c) kinetic energy intense at layers bounding several locations channel; (d) elevated turbulence low bend. unique hydrodynamics meander explains their behaviors, including rapid widening deepening channels bars pools. Moreover, this compares quantitatively depth‐averaged before after cutoff, demonstrating cross‐sectional redistribution streamwise momentum by secondary remains largely unchanged presence channel. implies 2D hydrodynamic models, parameterized calibrated for single‐channel meanders, suitable simulating within cutoffs.

Language: Английский

---

Spatiotemporal assessment of meander geometry and potential cutoff formation in the Gadadhar River of the Himalayan foothills

Environmental Earth Sciences, Journal Year: 2025, Volume and Issue: 84(7)

Published: March 28, 2025

Language: Английский

---

Rapid Infill of Abandoned Tidal Channels Creates Hotspots for Blue‐Carbon Accumulation in Coastal Wetlands

Geophysical Research Letters, Journal Year: 2025, Volume and Issue: 52(7)

Published: April 7, 2025

Abstract Sinuous channel networks dissecting tidal wetlands are highly dynamic and often abandoned as a result of captures meander cutoffs. However, the effects dynamics on blue carbon fluxes remain unclear. Analyses channels in Venice Lagoon (Italy) demonstrate that they take up organic at significantly faster rates than neighboring marshes. This is because, despite slightly lower sediment density, yield higher vertical accretion owing to topographic accommodation reduced flow velocities, which facilitate deposition particulate matter debris. We estimate capture 17 tons annually, equivalent 21 ha marshes, covering only 3.5 total. Hence we argue serve hotspots for blue‐carbon accumulation should be considered improve estimates coastal wetlands.

Language: Английский

---

Hydroacoustic measurements highlight channel impact on macrotidal mudflat morphodynamics

CATENA, Journal Year: 2024, Volume and Issue: 246, P. 108361 - 108361

Published: Sept. 10, 2024

Language: Английский

---