LSPIV analysis of ship-induced wave wash

Abstract

Ship-induced wave wash affects the hydromorphological and ecological state of rivers through various mechanisms. The direct proximity of the riverbank is usually the most exposed, as the hydrodynamic stresses are the highest in these shallow water areas. Contrary to the steady and almost still, natural flow conditions (i.e., no waves of anthropogenic source), shoaling and breaking of ship waves increase the hydrodynamic stresses by orders of magnitudes, having notable ecological consequences, and resulting in bank erosion as well. Due to the shallow water depths and temporary drying, conventional measurement techniques are no longer applicable in these areas. In this study, large-scale particle image velocimetry (LSPIV) is used to quantify the prevailing flow conditions. In the absence of ground truth data in the wave breaking region, a high-resolution computational fluid dynamics model—verified with field pressure and acoustic Doppler velocimetry data—is used for the cross-validation of the LSPIV results. The results underline the applicability of LSPIV for the hydrodynamic analysis of wave velocities in this special riverine swash zone, which is of key importance from the aspect of ecology and bank erosion as well. Graphical abstract