Wind Erosion in Western Queensland Australia

Chapter 2 – Land Erodibility ControlsChapter 2Land Erodibility to Wind: Systems AnalysisThis chapter addresses Objective 1 by presenting a review of the concepts of soil and landerodibility, and a systems analysis of the factors controlling wind erosion. The systemsanalysis addresses how meteorological, soil and vegetation conditions affect landsusceptibility to wind erosion. The review is synthesised in a conceptual model of the landerodibility continuum. The conceptual model can be used to understand approaches formodelling wind erosion reviewed in Chapter 3, and provides the foundation for developingnew soil and land erodibility models in Chapters 4 and 5.2.1 Erodibility Concepts and RankingsThe term “erodibility”, denotes susceptibility to erosion. Definitions of the term are oftenscale and process dependent. This means that in any study of erosion the term must be clearlydefined to avoid confusion. Bryan et al. (1989) review the use of “erodibility” in fluvialresearch. They identify implicit assumptions about which the term has been applied. Theseinclude (after Bryan et al, 1989: 393):• A soil erodibility ranking can be defined which is valid for all erosional processes;• A soil erodibility ranking can be uniquely defined by measurement of a few, usuallyphysical, soil properties; and• A relative erodibility ranking is not affected by short-term changes, particularly in soilmoisture status.The assumptions provide a good starting point for a discussion about the application of theterm in the field of aeolian research. In this field the term has been used to describe thesusceptibility of soils and land areas to wind erosion. Houghton and Charman (1986) providedefinitions of the terms erodibility, erosion hazard, and erosion risk in the context of winderosion:25