Complex Flow Patterns in the Scheldt Estuary: Field Measurements and Validation of a Hydrodynamic Model

Abstract

The morphology of the Scheldt estuary creates challenges for its different functions. Large shoals and adjacent channels with sharp bends result in challenging conditions for navigation. In order to provide estuarine managers with adequate answers, different research tools are necessary: numerical models, physical scale models, monitoring, and system understanding and expertise. This paper describes the validation of two numerical models, focusing on the Hansweert area, which is characterized by complex flow fields and important dredging works. In 2016, velocity measurements were executed over two spring-neap cycles using Acoustic Doppler Profiler devices. These velocity measurements are used for additional validation of two existing numerical models, describing the entire Scheldt estuary. Both models have shown good performance in large-scale tidal hydrodynamics, but uncertainty increases for local flow patterns, especially in shallow and intertidal areas. Adapting the local friction field improved significantly the representation of the measured complex flow patterns (e.g., large eddies) in the study area without impacting the overall model performance. This model allows both the improvement of our system understanding, e.g., formation of the large eddy, as well as the generation of flow patterns that are used in a ship simulator, where river pilots train to prepare for the challenging flow conditions in the field.