Trend Surface Analysis of Aeolian Sand Movement on the Southwest African Coast

Abstract

Trend surface analysis is employed to construct statistically significant trend maps of the areal variation in average grain size, sorting coefficient and roundness values of aeolian sand particles from the Namib sand sea, the Richtersveld and the Sandveld. All three parameters indicate that the sand is transported north in the Sandveld, west in the Richtersveld, and northeast in the Namib sand sea. This movement probably constitutes another minor source of Namib sand.

Characterisation of Coastal Sediment Properties from Spectral Reflectance Data

“…Sediment grain size analysis of field samples from Oyster Bay shows that overall they are fairly texturally uniform but with some significant differences in properties between different beach-dune sub-environments (Table 2) and a wide range of carbonate contents (Table 1). The values obtained for grain size properties are similar to other beach-dune systems in the region, e.g., [50,51]. The relatively limited textural and compositional differences mean that it is sometimes difficult to distinguish between such coastal samples, especially in wave-dominated shoreface environments and wind-affected supratidal environments, where sediments are relatively well sorted e.g., [2,4,11,52].…”

Prediction of Wind-Driven Transport Rate

“…(1) The effect of the topography of the sand surface over which the wind blows on the shear velocity and the magnitude of the blown sand volume. To date little work has been done in this respect, but reference can be made to Nakashima (1979), Svasek and Terwindt (1974) and Harmse (1985).…”