Geological Society of America

T9 Linking Coastal and Aeolian Geomorphology at the Beach-Dune Interface

Sunday, 4 November 2012
8:00 AM - 12:00 PM
207BC

OFFSHORE WINDS AND COASTAL FOREDUNES: ZONATION PATTERNS OF AIRFLOW AND TRANSPORT

Paper number: T9-5
Program: Technical Sessions
Time: 9:00 AM – 9:20 AM

Authors

Derek W.T. Jackson Presenting Author
University of Ulster, Coleraine
Irene Delgado-Fernandez
Edge Hill University, Ormskirk, N/A
A.C.W. Baas
Kings College London, London, N/A
J. Andrew G. Cooper
University of Ulster, Coleraine, N/A
K. Lynch
National University of Ireland (Galway), Galway, N/A
Meiring Beyers
Klimaat Consulting & Innovation, Guelph, ON

Abstract

The transfer of windblown sand between foredune systems and beaches represents a key component of sediment budget analysis along many soft sedimentary coastlines. Traditionally, onshore wind components in local wind regimes are examined whereas offshore wind events have been excluded from analysis.

Recent work has shown that if the topography of the foredune is appropriate then this offshore component can be steered or undergo flow reversal through leeside eddying to give onshore transport events at the back beach under offshore flow conditions. At particular distances from the foredune crest flow reattaches to the surface to continue its incident offshore direction. The location of this reattachment point has important implications for aeolian transport of sand on the back beach and foredune toe locations.

This study based at Magilligan, Northern Ireland, reports on recent field experiments investigating the zonation patterns of flow behaviour in the lee of the foredune-beach zone and how transport patterns vary as a result of different wind events. Airflow modelling using CFD supplements the field experiments and characterisation of this important coastal interface.