Spatio-temporal interaction of morphological variability with hydrodynamic parameters in the scope of integrative measures at the river Danube

Hydrodynamic parameters, determined by 3D numerical models, provide a basis for simulation tools such as sediment transport and habitat models. Whereas most of the time measures are evaluated using models right before and after measure implementation, little is known about the interaction of hydrodynamics, sediment transport and river morphologies including their spatio-temporal variability. This study investigates that interaction in the scope of a river engineering project at the Danube, containing integrative measures. Different morphologies led to a significant difference in hydrodynamics (e.g. bed shear stress: +11.8% at specific locations regarding its mean values). Morphodynamic models coupled with 3D hydrodynamics allow - in contrast to 1D/2D models - simulation times of a few months only within reasonable computational time. Hence, for the purpose of assessing measures, scenarios with high and low morphologies, embodied as an initial condition, should be considered for morphodynamic models or habitat models to cover effects of spatio-temporal variability.