Wind Erosion in Western Queensland Australia

Chapter 8 – Conclusionscontrols reviewed in Chapter 2, and provided a synthesis of the limitations to the models. Thereviews indicated a significant lack of research into quantitative modelling of spatial andtemporal variations in soil erodibility, and application of models to assess spatial andtemporal patterns in controls on wind erosion at the landscape scale.The third research objective was to address these deficiencies by developing a framework formodelling temporal changes in soil susceptibility to wind erosion. The model framework waspresented in Chapter 4. First, a conceptual model of the soil erodibility continuum wasdeveloped relating soil textural characteristics, aggregation and surface crust conditions towind erosion rates. The conceptual model is based on empirical research from Australia andthe United States reviewed in Chapter 2. A framework for modelling temporal changes in soilerodibility within the continuum was then presented. The model framework sought tocharacterise the nature and timing of changes in soil erodibility in response to climatevariability and land management pressures. Parameterisation and integration of the modelinto AUSLEM were restricted by a lack of quantitative research into soil aggregation andsurface crust responses to climate variability and land management. This meant that analternate approach to accounting for soil erodibility was required in modelling landerodibility in Chapters 5 to 7. To conclude the research, a synthesis of published workexamining controls on soil erodibility was presented. The synthesis highlighted gaps in ourunderstanding of factors driving soil erodibility dynamics and identified future researchpriorities to parameterise the model and advance soil erodibility modelling.The second aim of this thesis was to develop AUSLEM into a functional model to assessland erodibility across western Queensland, Australia. This aim was achieved through thefourth research objective. Development of the model was presented in Chapter 5 andpublished in Webb et al. (2009). The model was developed from process relationshipsidentified in the systems analysis in Chapter 2, and built upon a land erodibility model,AUSLEM, developed by Webb et al. (2006). The original rule-based structure of AUSLEMwas replaced with an empirical model that addressed the requirements for modelling landerodibility through a continuum, and at the landscape scale. AUSLEM was designed in a GISenvironment and can be run to assess spatial patterns in land erodibility at a 5 x 5 km spatialresolution on a daily time-step across western Queensland. Temporal changes in soilerodibility were accommodated in the model by restricting the output analyses to monthlytemporal resolutions at landscape to regional spatial scales.191