Geomorphic Modeling of Macro-Tidal Embayment with Extensive Tidal Flats: Skagit Bay, Washington

Abstract

Abstract : The long term goal for the project is to better understand processes affecting morphologic changes of muddy tidal flats and to quantify the effects of tidal action, river discharge and shoreline development (e.g. dikes and jetties) on these changes. Our objective of this effort is to demonstrate the use of a community numerical model for prediction and investigation of tidal flat morphology and forcing parameters. The ONR/Delft community model is being evaluated as a physics-based numerical simulation tool for several investigations, and this effort applies it specifically to tidal flat and channel systems. Within this objective, we examine the relative roles of tidal action, river discharge, and shoreline modification on flow over the tidal flats and resulting effects on morphologic modeling. From a model tuning perspective, this objective includes advancing the understanding of the sensitivity of the model to parameter value adjustments and to the inclusion or exclusion of specific sediment transport processes and characterization in tidal flat and channel systems. The model fidelity should be improved by incorporation of observational data for configuration, assignment of boundary and initial conditions, and sediment source-term characterization, and for calibration and validation efforts.