Equilibrium beach profile with net cross-shore sand transport
Date
2018
Journal Title
Journal ISSN
Volume Title
Publisher
University of Delaware
Abstract
Periodic beachfill placement and frequent overwash result in net offshore and
onshore sand transport, respectively. Three tests consisting of fifty 400-s runs were
conducted in a small-scale wave flume to examine the effect of net cross-shore sand
transport on an equilibrium profile. The foreshore of an equilibrium profile with no
net sand transport shifted seaward after periodic sand placement near the shoreline.
Frequent sand overwash resulted in the landward shift of the shoreline. The profile
changes among the three tests were relatively small and the shoreline shifts were less
than 0.1 m. An analytical model for an equilibrium profile with net cross-shore sand
transport is developed by approximating existing formulas for onshore bed load and
offshore suspended sand transport in the inner surf zone. The model predicts the
horizontal shift of the equilibrium profile under net cross-shore sand transport, which
is the maximum at the shoreline and approaches zero at the closure depth. The model
calibrated using the three tests are used to estimate the seaward shift of the shoreline
on periodically-nourished beaches of prototype scale. The estimated shift is of the
order of 1 m or less but will need to be verified using field data.
Description
Keywords
Applied sciences