Abstract
A depth‐average model using a finite‐volume method with boundary‐fitted grids has been applied to simulate morphological processes in the Danube River. The numerical model consists of three basic modules: a hydrodynamic module describing the depth‐average flow and the water surface elevation, a sediment transport module, and a sediment‐balance module providing the sedimentation and erosion rate and the bed level deformation. The secondary flow transport effects are taken into account by adjusting the dimensionless diffusivity coefficient in the depth‐average version of the k — ϵ turbulence model. The numerical model has been developed, tested and validated previously by computing various flow situations in laboratory channels and natural rivers. This paper presents the results of an application of the model to flood situations in one stretch of the Danube River. The predictions are compared with field data measurements. Detailed comparison of the flow field shows generally good agreement. Some problems of model calibration for sediment transport are discussed. Calculations have been carried out to study morphological characteristics under extreme flood conditions in the river stretch.