The use of topographic scale models in predicting eolian dust erosion in hilly areas: field verification of a wind tunnel experiment

Eolian erosion of natural dust in an area of 53 ha, situated in the northern Negev Desert, is investigated in detail both in the wind tunnel (erosion simulations on a topographic scale model) and in the field. The wind tunnel results and the field results show good agreement, indicating that wind tunnel simulations of eolian dust erosion on scale models of complex topography may predict, at least to an acceptable level, the erosion-sensitive areas in a hilly landscape of nearly uniform surface roughness. The experiments also indicate that a restricted height distortion of scale models may be acceptable to determine the areas of highest erosion. In addition, wind tunnel blockage percentages up to 10% may be allowed to obtain acceptable erosion patterns on the model. When surface roughness is more or less uniform, eolian erosion of dry dusty sediments is almost entirely determined by macro-topography. If, however, surface roughness is highly variable over the field, the initiation of eolian erosion is also largely a function of local micro-topography.