Australian Digital Theses Program

Thesis Details
Title	An Integrated Wind Erosion Modelling System with Emphasis on Dust Emission and Transport
Author	Lu, Hua
Institution	University of New South Wales
Date	2000
Abstract	In this thesis, an integrated wind erosion assessment and prediction system has been developed. This system couples a physically based dust emission scheme, a high resolution limited area weather prediction model, a dust transport model, and a high resolution GIS (Geographic Information System) database. A simple expression for particle threshold velocity has been derived by considering the force balance of a single particle resting on the surface. Theoretical analyses have been performed to confirm that the main mechanism for dust uplifting is sand saltation bombardment rather than direct aerodynamic entrainment. A new model for dust emission by saltation bombardment is proposed and validated against experimental data. Preliminary sensitivity tests for the new dust emission model have been carried out by examining the dependence of dust emission rate on a range of parameters. The transport of airborne dust is modelled by using the particle mean concentration equation. The time-dependent advection terms are discretized and solved numerically by a multi-dimensional wave-propagation slope-limiter scheme. Some computational features of the integrated model are discussed in terms of its coupling, module decomposition, data handling and efficiency. A systematic sub-grid treatment is designed to extract soil surface parameters from the GIS database for large scale modelling. The integrated system is applied to investigate the February 1996 dust storms over the Australia continent. The simulated wind erosion pattern and intensity are in good agreement with available meteorological records and satellite images. It reveals that the system can be used to identify areas and periods under wind erosion threat as well as the responsible environmental factors.
Thesis	01front.pdf 165.2 Kb 02Chapter1.pdf 241.0 Kb 03Chapter2.pdf 214.4 Kb 04Chapter3.pdf 295.5 Kb 05Chapter4.pdf 358.2 Kb 06Chapter5.pdf 322.4 Kb 07Chapter6.pdf 5036.1 Kb 08Chapter7.pdf 9153.2 Kb 09Chapter8.pdf 63.0 Kb 10Bibliography.pdf 92.7 Kb