Field Study of Beach Water Content as a Guide to Wind Erosion Potential

Abstract

Abstract Wind erosion is strongly governed by water adsorbed onto the surfaces of sedimentary particles and held by capillarity in lenses at interparticle contacts. Unfortunately, conventional measurement techniques cannot adequately characterize the distribution of surface pore water content over a continuous, horizontal plane. The present field study, carried out on two beaches on the north shore of Lake Ontario, confirms that the water table level plays an important role in governing this distribution in the absence of precipitation. The maximum extent of the capillary fringe was determined to be about 400–500 mm, consistent with prediction from a physically based model for which the pore radius is assumed to be one-fifth of the mean grain diameter. The brightness of the sand surface also was confirmed to be a good indicator of the amount of pore water present. A simple remote sensing method is described that is nondestructive and continuously tracks pore water variability at the beach surface through ...