Advances in research on the influence of vegetation on river flow and bank morphology evolution

As an important resistance factor of the river system, vegetation plays a vital role in the evolution of river morphology. The existence of the vegetation above ground structure changes the resistance of the river channel, the shear stress of the river bed, the velocity distribution and the turbulence characteristics of the river flow. At the same time, the existence of the vegetation roots can enhance the strength and stability of the riparian soil. This article reviews the effects of vegetation stems on water flow characteristics and the effects of vegetation roots on the stability of riparian, and points out that in future vegetation water flow research, the influence of vegetation branches and leaves on water flow characteristics, as well as the deformation and swing of flexible vegetation under the action of water flow, should be further considered. And the impact of the boundary conditions of the river forms should be fully considered, particularly the vegetation characteristics of branching river need further studies. In the aspect of vegetation root system for soil consolidation and bank protection, the heterogeneity of the riparian soil, the erosion of the river flow on the riparian, and the impact of water seepage on the mechanical properties of the beach soil should be considered at the same time. In the prediction of vegetation river evolution, the hydrodynamic problems and soil mechanics problems with vegetation and the mutual feedback response mechanism between them should also be comprehensively considered.