NUMERICAL MODELLING OF STORM-DRIVEN SEDIMENT TRANSPORT IN CURRITUCK SOUND, NC

Abstract

Storms such as hurricanes generate large storm surges and surface waves in typically low-energy estuarine environments. This enhances sediment transport and affects morphology, impacting navigation and aquatic vegetation. To better understand and predict these impacts, a numerical model corresponding to a 20 km long section of Currituck Sound, a narrow back-barrier estuary in North Carolina, was implemented with a 25 m resolution using Delft3D-SWAN for two 2016 tropical cyclones. Model results compare well with observations from instrumented platforms for both waves and water levels, and the simulated bed shear stress qualitatively matched observed trends in turbidity with considerable spatiotemporal variation. Satellite observations of red and infrared reflectance indicate considerable differences in total suspended matter between the two storms despite similar peak wind speeds. These preliminary results indicate detailed in situ observations and high resolution coupled numerical models can be used to quantify estuarine sediment transport during cyclonic storms.