Estimating Alongshore Sediment Transport and the Nodal Point Location on the Delaware–Maryland Coast

Abstract

An approach to estimating sediment transport along the Delaware–Maryland coast is described. Wave information study (second generation model, WISWAVE 2.0) hindcast frequency-direction spectra from 1980 to 1999 are used to generate a radiation stress-conserving angle for bringing offshore waves to breaking to estimate alongshore sediment transport. Using standard values for the coefficients in the United States Army Corps of Engineers’ Coastal Engineering Research Center (CERC) equation yields 20-year mean alongshore sediment transport rates between 470,942 and −517,088 m3 /year depending on alongshore location after shoaling waves to shore. Interannual variability is large with SDs between 95,078 and 241,313 m3 /year again depending on alongshore location. Alongshore sediment transport rate estimates are commensurate with past studies using WIS data but overpredict the typically cited value of ∼100,000 m3 /year near Indian River Inlet, Delaware based on sediment budget data by a factor of 3–4. This ove...