Wind Erosion in Western Queensland Australia

Chapter 1 - Introduction• The ability of soils to sustain vegetation and livestock decreases;• Agricultural and pastoral productivity decreases;• Nutrient enrichment of streams occurs with the influx of wind blown sediments;• Spread of herbicides and pesticides off-farm; and• Damage to property (e.g. fences and roads) and farm infrastructure.Off-site effects of wind erosion are relevant across scales and relate to the transport anddeposition of mineral dust which (after Dentener et al., 1996; Prospero et al., 2002; Jickells etal., 2005 and others):• Alters the radiation balance in the atmosphere through scattering and absorption ofradiation;• Affects cloud nucleation and optical properties of the atmosphere;• Acts as a reactive mineral species in the atmosphere;• Moderates the photochemical oxidant cycle and biogeochemical processes;• Acts as a source of Fe that may be metabolised by cyanobacteria and may subsequentlymoderate the nitrogen chemistry of the ocean;• Acts as a source of Fe that may be a limiting nutrient for phytoplankton; and• Provides reaction sites for ozone and nitrogen molecules.Understanding spatial and temporal variations in wind erosion is required to develop methodsfor managing land degradation at the field (10 3 m 2 ) to landscape (10 3 km 2 ) scales, and forunderstanding the regional to global scale consequences of dust transport. Surprisingly littleattention has been given to the development of methods for assessing spatio-temporalpatterns in land areas susceptible to wind erosion.Existing maps of the location and extent of regions prone to wind erosion are based on: fieldassessments of affected areas (Carter, 1985; Mezösi and Szatmári, 1998); observational dataon dust-storm frequencies (Goudie and Middleton, 2006); analyses of satellite imagery(Prospero et al., 2002; Washington et al., 2003); and in a few cases spatial modelling (Böhneret al., 2003; Coen et al., 2004). However, these methods for assessing wind erosion have anumber of limitations. These include:2