CGRG Bibliography of Canadian Geomorphology
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Author : Bauer, B.; Davidson-Arnott, R.; Hesp, P.; Namikas, S.; Ollerhead, J.; and Walker, I.
Date : 2006.
Title : Aeolian sediment transport conditions on a beach: I. Surface moisture and wind fetch effects on mean transport rates.
Publication : Sixth International Conference on Aeolian Research. July 24-28 2006, University of Gueph, Guleph, Ontario, Canada. Program and Abstracts. Edited by: W.G. Nickling, S. Turner, J.A. Gilles and M. Puddister.
Issue :
Page(s) : 113.
Abstract
Wind conditions, surface moisture content, sediment transport rate and sediment flux intensity were measured during a storm on October 11, 2004 at Greenwich Dunes, Prince Edward Island. Cup anemometers were deployed along a horizontal profile normal to the coastline and on a vertical tower located on the mid-beach, which also included a 2-D Windsonic anemometer at 4 m height for speed and direction. Surface moisture content and surface temperature were measured at 2.5 m intervals across three profiles using a Delta-T moisture probe and an Omega infra-red thermometer. Sand transport was measured using integrating vertical sand traps spaced along the main profile line and Safires collocated with the vertical traps. Surface moisture content on the mid and upper beach ranged from 3-6% in the morning. From midday onward, the zone of saturation associated with wave run-up, storm surge, and tidal inundation migrated rapidly landward. Wind speeds increased progressively toward early evening and wind direction was obliquely onshore (about 10-30° from shore parallel) thereby significantly increasing fetch distance. Wind speed measured at 0.6 m heights showed a consistent decrease landward because of beach-surface-induced internal boundary layer development. Sand transport increased across the beach with maximum transport occurring at fetch distances of 50-100 m. During the course of the day, the available fetch became shorter than the critical fetch as indicated by continually increasing transport rates measured at more landward positions. Maximum sediment transport rates were generally lower than predicted using the Bagnold equation early in the day, but were 1.5-1.75 times greater than predicted in the afternoon.
Bibliography of Canadian Geomorphology