Integrating High-Resolution Bathymetric Data for Enhanced Calibration of Tidal Models: A Case Study of the Saint-Marcouf Region

Tidal models are employed in various applications, including the prediction of coastal hazards and environmental impact assessments. This study presents an innovative approach to assimilating high-resolution bathymetric data and calibrating a two-dimensional tidal model. The bathymetric data with a resolution of few tens of centimeters allows for the identification of bottom features, particularly sand dunes. The orientation of sedimentary structures, such as sand dunes, reveals the direction of the residual current. The acquired data is integrated into a tidal model for the Saint-Marcouf region, a microtidal area in the English Channel, known for its sand dunes aligned in varying directions. Following this integration, the Telemac2D model is calibrated using parameters such as bottom friction in different spatial zones and turbulent viscosity. The 3DVar data assimilation algorithm is employed to incorporate the observed residual current direction and calibrate the model. This process is accomplished by coupling the ADAO (a data assimilation and optimization module) with Telemac2D. The data assimilation begins with a twin experiment in the initial phase, utilizing synthetic data of the spatial distribution of the residual current direction. This study will demonstrate the benefits of using high-resolution bathymetric data to obtain information from sedimentary structures, to enhance the performance of hydrodynamic models through data assimilation.