Simulation-based Evaluation of Hydrographic Data Analysis for Dune Tracking on the River Rhine

Abstract

Knowledge of the static and morphodynamic components of the river bed is important for the maintenance of waterways. Under the action of a current, parts of the river bed sediments can move in the form of dunes. Recordings of the river bed by multibeam echosounding are used as input data within a morphological analysis in order to compute the bedload transport rate using detected dune shape and migration. Before the morphological analysis, a suitable processing of the measurement data is essential to minimize inherent uncertainties. This paper presents a simulation-based evaluation of suitable data processing concepts for vertical sections of bed forms based on a case study at the river Rhine. For the presented spatial approaches, suitable parameter sets are found, which allow the reproduction of nominal dune parameters in the range of a few centimetres. However, if parameter sets are chosen inadequately, the subsequently derived dune parameters can deviate by several decimetres from the simulated truth. A simulation-based workflow is presented, to find the optimal hydrographic data processing strategy for a given dune geometry.