Wind Erosion in Western Queensland Australia

Chapter 1 - Introduction1. Field surveys have historically been conducted as individual studies and have onlyprovided snapshots of the landscape condition relevant to the climatic conditions at thetime of survey (Leys, 1999).2. The analysis of dust-storm frequencies relies on the interpolation of data between distantlocations, e.g. meteorological stations in drylands are often >100 km apart, and so isgenerally unable to resolve dust source areas at scales less than ~10 5 km 2 (McTainsh andPitblado, 1987).3. The analysis of aerosol optical depth imagery (Prospero et al., 2002; Washington et al.,2003) and development of dust enhancing indices (Legrand et al., 1994; Miller, 2003) hasprovided a capability to detect point source and regional dust source areas using satelliteimagery. However, these methods cannot provide information on land erodibility unlessthe surface is eroding at the time of image acquisition.4. While numerous wind erosion models have been developed, few have been appliedspecifically to assess land susceptibility to wind erosion. Examples of this applicationhave been restricted to cultivated fields and over small geographic extents (e.g. Coen etal., 2004), or very coarse spatial resolutions (Ginoux et al., 2001).There remains a great deal of speculation about the location and strengths (erodibility) ofwind erosion prone areas (Grini et al., 2005). This is a global issue, relevant to ourunderstanding of the world’s major dust producing regions in Africa, the Middle East, Asia,North and South America, and Australia (Hermann et al., 1999). Quantitatively describingspatial and temporal patterns in land erodibility is essential for enhancing land managementstrategies to combat land degradation in dryland environments. Understanding landerodibility dynamics at the landscape scale (10 3 km 2 ) is also required to better understandregional scale dust emission and transport processes. Without a detailed knowledge of howthe erodibility of drylands responds to climate variability and land management, or of thefeedbacks between local wind erosion activity and regional climate, our capacity to mitigatepotential impacts of global climate change on this degradation process will be severelychallenged.This thesis develops a model to assess land susceptibility to wind erosion, i.e. landerodibility, in the rangelands of western Queensland, Australia. This chapter provides abackground to the research problem and synthesis of the research requirements. This isfollowed by a statement of the research aims and objectives, and research approach. The3