ABSTRACT: The effect of wind gusts on sand transport on a beach.

CGRG Bibliography of Canadian Geomorphology
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Abstract

A field experiment was carried out at Skallingen on the North Sea coast of Denmark in November, 2000 with the purpose of measuring the effects of wind speed and gustiness, moisture content and angle of wind approach on the instantaneous and average sand transport rates. This paper reports on an analysis of instantaneous sediment transport in relation to wind gusts on two days, one with relatively dry beach conditions and one with relatively moist conditions. Wind speeds were measured with cup anemometers and instantaneous sediment transport with vertical traps coupled to electronic balances. Moisture content was measured gravimetrically using samples taken along a beach profile at intervals of one to two hours. The correlation between instantaneous wind speed and sediment transport is much higher (R2 = 0.79) on the day with relatively dry conditions where transport is nearly continuous, compared to that for relatively moist conditions when sand transport is much more intermittent (R2 = 0.34). Spectral analysis and autocorrelation show that transport rates closely reflect the temporal pattern of wind gusts and there is no significant lag effect between the wind gusts and transport rates. Plots of instantaneous sediment transport versus wind speed can be used to provide a measure of the threshold for sediment transport under fluctuating wind conditions and with varying beach moisture content.

Bibliography of Canadian Geomorphology