Sand movement by wind

Abstract

Sand movement on the coast by wind action can be a major factor in some areas, yet very little is known about the basic mechanisms of movement by wind. With the growing use of artificial placement of sand material for beach restoration and protection, movement of sand by wind in the area shoreward of the waterline has become more and more a matter of concern. The need for greater knowledge in this area has recently been emphasized by proposed plans for the rehabilitation of vast offshore sand island areas along the eastern seaboard. This report discusses some earlier experimental results in wind tunnels, and describes and compares results obtained from new wind tunnel tests. Work by another investigator, directly related to the author's work, has been included in an addendum. This latter work extends the investigation to smaller sand size range and suggests that different relationships for threshold shear velocity for sand movement obtain for the smaller sand size distributions. Of particular interest are tests on the influence of moisture content on sand movement. The experimental date clearly demonstrate that as the sand moisture content increases, the value of the threshold shear velocity of sand movement may also materially increase. Quantitative expression of this effect is obtained.