Numerical modeling of the hydraulic impact of riparian vegetation

This paper presents results of numerical modelling of riverbed segment with riparian vegetation performed with use of CCHE2 software. Vegetation zones are places where dynamic of water flow increases. Therefore, there is a need of careful examination of hydraulic impact structure of such zones. Accurate research is necessary and should be performed with use of physical or numerical models, two or three dimensional. Paper presents distribution of velocity and area of water surface for two variants of vegetation deposition acquired in CCHE2D software and modelled for riverbed with distinctive riparian vegetation. Results point to significant (30–40%) increase of maximal velocities in riverbed with riparian vegetation, while directly near the vegetation there were zones with very low velocities. Local damming occurs before vegetal zone. Maximal shear stress in zones with increased velocity is significantly augmented compared to conditions with no vegetation, which can cause more intensive erosion in those zones