Shoaling wave shape estimates from field observations and derived bedload sediment rates

Journal of Marine Science and Engineering
By: , and 

Links

Abstract

The shoaling transformation from generally linear deep-water waves to asymmetric shallow-water waves modifies wave shapes and causes near-bed orbital velocities to become asymmetrical, contributing to net sediment transport. In this work, we used two methods to estimate the asymmetric wave shape from data at three sites. The first method converted wave measurements made at the surface to idealized near-bottom wave-orbital velocities using a set of empirical equations: the “parameterized” waveforms. The second method involved direct measurements of velocities and pressure made near the seabed: the “direct” waveforms. Estimates from the two methods were well correlated at all three sites (Pearson’s correlation coefficient greater than 0.85). Both methods were used to drive bedload-transport calculations that accounted for asymmetric waves, and the results were compared with a traditional excess-stress formulation and field estimates of bedload transport derived from ripple migration rates based on sonar imagery. The cumulative bedload transport from the parameterized waveform was 25% greater than the direct waveform, mainly because the parameterized waveform did not account for negative skewness. Calculated transport rates were comparable to rates estimated from ripple migration except during the largest event, when calculated rates were as much as 100 times greater, which occurred during high period waves.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Shoaling wave shape estimates from field observations and derived bedload sediment rates
Series title Journal of Marine Science and Engineering
DOI 10.3390/jmse10020223
Volume 10
Issue 2
Year Published 2022
Language English
Publisher MDPI
Contributing office(s) Woods Hole Coastal and Marine Science Center
Description 223, 27 p.
Country United States
State Florida, Massachusetts, New York
Other Geospatial Fire Island, Martha Vineyard, Matanzas Inlet
Google Analytic Metrics Metrics page
Additional publication details