Abstract
This study models a dam-break flow over a bed by using a depth-averaged numerical model based on finite-volume method and computes the dam-break flow and bed morphology characteristics. The generalized shallow water equations considering the sediment transport and bed change on dam-break flow are adopted in the numerical model, and the vegetation effects on the flow and morphological changes are considered. The model is verified against three cases from the laboratory and field data documented in the literature. The numerical results are consistent with the measured results, which show that the model could accurately simulate the evolution of the dam-break flows and the morphology evolution of bed within a computational domain with complex plant distribution. The results show that the riparian vegetation in the waterway narrows the channel and reduces the conveyance capacity of river. The flood flow is diverted away from the vegetation community toward two sides and forms a weak flow region behind the vegetation domain. The resistance of plants markedly reduces the flow velocity, which directly alters the fluvial processes and influences the waterway morphology.
Highlights
Increase in catastrophic flood events has attracted increasing attention on the prediction of their dynamics and bed change evolution, especially in relation to riverine plant effect
Because numerical method has its advantages of wide application range, repeatability, and low cost compared to other methods, some effective and efficient numerical methods were developed for understanding flood wave propagation in urban areas, complex open channels, and overland flow systems [4]
Dam-break flows were usually formed in mixed flow regimes with discontinuities; the numerical schemes that were often used for such studies include the shock-capture schemes, such as Total Variation Diminishing schemes (TVD) and Godunov type schemes [5,6,7,8]
Summary
Increase in catastrophic flood events has attracted increasing attention on the prediction of their dynamics and bed change evolution, especially in relation to riverine plant effect. During a flooding hazard involving rapid transients, interaction between dambreak waves and topography changes could be significant; the interaction was ignored in the early numerical models for simulating dam-break flows over mobile beds. To correctly predict the consequences of a dam failure in a complex topography, the interaction between flow and bed morphology must be modeled using a coupled solution [9,10,11,12] Such models are based on either fixed rectangular grids or uniform curvilinear boundary-fitted grids and, simulate the large-scale flow features on a structured grid system, which may reduce the modeling accuracy and efficiency [13,14,15]. A depth-averaged hydrodynamic and sediment transport model, based on finite-volume method, is developed to simulate the flood waves and bed change due to vegetation effect. The hydrodynamic variation and the evolution of bed elevation through the rigid vegetation domain are investigated and discussed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
