Soil- the source of dust

Soils are formed by the weathering of rocks, and are also influenced by climate, organisms, the sloping of the land and the effect of time. Soils are generally classified into groups, but the exact combination of the above factors makes each soil unique.

As the source of dust, knowing about soils is helpful in learning whereabouts dust comes from – transported dust matches the same characteristics as the dust component of the soil it came from. Scientists examine the different soils across Australia and use this information to work out whereabouts particular dust events originated.

Soil erodibility by wind can be measured by testing soil strength, crust cover, the amount of erodible material on the soil surface, aggregation levels, particle-size characteristics, soil chemistry, and by simulating wind erosion (using a wind tunnel measurement device).

Each soil type has a different susceptibility to wind erosion. Sandy soils common to the Mallee region or desert loam soils are highly vulnerable to wind erosion. This is attributed to their low aggregation, variable soil moisture and the tendency to disaggregate with disturbance. In contrast, the highly aggregated soils such as black earths and ferrosols have a low susceptibility.