Author(s): Rodrigo Maia; Bruno Oliveira
Keywords: Hot start approach; Hydro and morphodynamic modelling; Bathymetric uncertainty; Morphological sensitivity; River rehabilitation
Abstract: The present study proposes, systematizes and validates a new, robust hot-start approach to numerical hydro-morphodynamic modelling, aiming to improve the quality of the interpolated bathymetrical data used in the referred models for representing river channels. This approach works by criteriously removing the small scale systemic errors in a channel’s bathymetry which often obfuscate the behaviour of fluvial morphodynamics, thereby improving the accuracy of the interpolated bed level along the modelling grid and the intelligibility of morphodynamical simulations. The pre-modelling approach was demonstrated using data from a case study in Portugal. The improvements obtained in terms of the quality of the morphology were both qualitatively and quantitatively assessed. Pre-modelling was proven to produce, at least, small improvements regarding the overall bed level accuracy (∼5% reduction in mean error) and significant benefits to the overall intelligibility of the results (with up to 22% reduction in the spatial entropy of morphodynamics and up to 55% increase in the agreement between theoretical and simulated values for each different scenario).