Dust storms occur over large areas of arid and semi-arid Australia and
are responsible for eroding large quantities of topsoil, yet the clim
atic controls on their occurrence are poorly understood. The Et Index
of wind erosion, described here, uses readily available meteorological
data to identify two major wind erosion regions in eastern Australia
and describes seasonal controls of wind conditions and soil moisture u
pon dust storm occurrence. These results provide a better understandin
g of the drought-dust storm relationship in Australia, and the model h
as applications in broadscale wind erosion studies in the arid and sem
i-arid developing world. (C)1998 Academic Press Limited.