A depth‐averaged two‐dimensional model for flow, sediment transport, and bed topography in curved channels with riparian vegetation

Abstract

[1] A depth-averaged two-dimensional numerical model has been developed to simulate flow, sediment transport, and bed topography in river channels with emergent and submerged rigid vegetation and large woody debris. The effect of helical flow in bends is considered by adopting an algebraic model for the dispersion terms in the depth-averaged two-dimensional momentum and suspended-sediment transport equations and by adjusting the bed load transport angle. The governing equations are discretized using the finite volume method on a nonstaggered, curvilinear grid. Model validity has been assessed using experimental data observed in both fixed-and movable-bed laboratory flumes and a natural channel with submerged and emergent rigid vegetation. In general, mean flow velocities, sediment transport rates, and changes in bed topography predicted by the model agree well with the experimental observations. For laboratory and field cases, root-mean-square relative errors for velocities were less than about 13% and 44%, respectively, and about 50% of errors for changes in bed topography were less than 14.5% and 8% of the flow depth, respectively.

Numerical analysis of effects of large wood structures on channel morphology and fish habitat suitability in a Southern US sandy creek

“…FVMbased CCHE2D model is a depth-averaged 2D model for flow, sediment transport, water quality, and ecology in aquatic systems, which solves the depth-averaged 2D shallow water equations using the FVM on a nonstaggered, curvilinear grid (Wu, 2004;Wu et al, 2005). The sediment transport model simulates the nonequilibrium transport of nonuniform total-load sediment.…”

Numerical Experiments of Vegetation Growth Effects on Bed Change Patterns

“…식생에 의한 흐름특성 변화 및 하상변동을 예측하 기 위해 간단한 1차원 수치모형부터 복잡한 3차원 수치모형이 개발되어왔다 ( Van de Wiel and Darby, 2004;Wu et al, 2005;Kang and Choi, 2007). 하지 만 실규모에서 장기간 식생에 의한 흐름 및 하상변동 을 계산하기 위해 2차원 수치모형이 가장 적절해 보 인다 (Wu et al, 2005).…”

“…하지 만 실규모에서 장기간 식생에 의한 흐름 및 하상변동 을 계산하기 위해 2차원 수치모형이 가장 적절해 보 인다 (Wu et al, 2005). 국내에서는 Kim et al (2010) 이 운동량 방정식에 식생 항력항을 추가하여 수심 적 분된 2차원 수치모형을 개발하고 단단면 및 복단면 실험수로에서 식생에 의한 수위 및 유속을 비교하여 모형을 검증하였다.…”

Unified Integral Model for Fluvial and Aeolian Sediment Transport

“…The integral average method is widely applied to wide shallow river or estuary and large-scale reservoir numerical simulation [16][17][18]. It is based on shallow water theory frame, in which fluid is considered as homogeneous and incompressible, and the vertical acceleration is negligible compared with the acceleration of gravity so that static pressure distribution can be assumed.…”