Coastal Change Processes- Outer Banks, NC

Coastal Change Processes

Coastal Change Processes

The primary objective of this project is to increase our understanding of the physical processes that cause coastal change, and ultimately improve our capability to predict the processes and their impacts. 

Landing Page

Science Center Objects

The objective of this task is to improve the capabilities of coastal change models to predict large-scale shoreline change on open-ocean sandy coasts, with specific application to the Northern Outer Banks of North Carolina. Numerical models will be tested and developed using high-resolution observations of geological framework and shoreline change in North Carolina, with the objective of first simulating past changes (hindcasting) and then developing a forecasting capability.

Geologic Framework

The coastal change observations collected under the North Carolina Regional Coastal Erosion Study provide unprecedented resolution, revealing patterns of shoreline change along 130 km of coast at an interannual (several year) time scale. Geologic framework observations reveal bathymetric features and near-surface sediment distribution patterns that appear to be tied to the observed shoreline variability. Along one 5-km section of coast, a strong pattern of interannual erosion and accretion appears to be associated with a set of shore-oblique bars on the shoreface (in 4 -15 m water depths).  Described further in Thieler and others, 2013, These geologic framework data will be used in numerical models to assess shoreline change due to sediment transport in the alongshore direction due to storms driven flows.

Numerical Modeling

Numerical modeling along the Outer Banks of North Carolina is being performed to hindcast coastal change. We are using the COAWST modeling system to simulate multiple grids of wave and ocean circulation. The three grids consist of an offshore grid (C ; 257x 171); a shelf grid (B; 41x 259); and a nearshore grid (A ; 100 x 1522). The models are being simulated for a period of 24 years (Jan 1979 - Dec 2002). Results will identify processes of alongshore sediment transport during that time period.

Example of a rip current experiment.

Example of a rip current experiment. Colors show bathymetry and arrows show velocity vectors after 1 h of model simulation.