Wind Erosion in Western Queensland Australia

Chapter 2 – Land Erodibility ControlsFigure 2.10 Space-time plot illustrating the spatial and temporal scales over which wind erosioncontrols operate.Conditions conducive to wind erosion are those that minimize the forces holding particles tothe soil surface, and maximize the wind shear velocity. Gillette (1999:75) summarised theseas being:• High wind speeds;• A dry environment that lacks soil moisture, soil crusting and aggregation;• Unvegetated surface free of rocks, pebbles, cobbles and boulders leading to a lack of dragpartitioning and sediment trapping;• Sandy sediments, or particle size, crusting and aggregation leading to the low thresholdfriction velocities (80 < grain diameter < 120 µm);• Disturbance mechanisms to break down aggregates and surface crusts;• High particle availability and a thick deposit so that supply limitation does not occur;• Low binding energies of particles suspended in the soil matrix (poor aggregated);• Long fetch – leading to the Owen Effect – sediment lines up parallel to strong winds; and• Smooth surface (z 0 < 0.1 cm) – leading to low threshold friction velocity and a lack ofparticle trapping.64