- Title
- Simulations of spatial variability in particle-size emissions during wind erosion events
- Creator
- Butler, Harry J.; McTainsh, Grant H.; Hogarth, William L.
- Relation
- Earth Surface Processes and Landforms Vol. 37, Issue 13, p. 1362-1375
- Publisher Link
- http://dx.doi.org/10.1002/esp.3245
- Publisher
- John Wiley & Sons
- Resource Type
- journal article
- Date
- 2012
- Description
- This study simulates how spatial variations in particle-size emissions from a playa affect bulk and size-resolved dust concentration profiles during two contrasting wind erosion events (a small local and a large regional event) in the Channel Country, Lake Eyre Basin, Australia. The regional event had higher dust concentration as a result of stronger frontal winds and higher erodibility across the playa. For each event, two emission scenarios are simulated to determine if measured size-resolved dust concentration profiles can be explained by spatial variability in source area emissions. The first scenario assumes that particle-size emissions from source areas occur at a uniform rate, while the second scenario assumes that particle-size emissions vary between and within source areas. The uniform emission scenario, reproduced measured bulk dust concentration profiles (R² = 0·93 regional and R² = 0·81 local), however simulated size-resolved dust concentration profiles had poor statistical fits to measured size-resolved profiles for each size class (the highest were R² = 0·5 regional and R² = 0·3 local). For the differential particle-size emission scenario, the fit to the measured bulk dust concentration profiles is improved (R² = 0·97 regional and R² = 0·83 local). However, the fit to the size-resolved profiles improved dramatically, with the lowest being R² = 0·89 (regional) and R² = 0·80 (local). Particle-size emission models should therefore be tested against both bulk and size-resolved dust concentration profiles, since if only bulk dust concentration profiles are used model performance may be over-stated. As the source areas in the first 90 m upwind of the tower were similar for both events, the percentage contributions of each particle-size class to total emissions can be compared. The contribution of each particle-size class was similar even though the wind speed, turbulence and dust concentrations were significantly different; suggesting that the contribution of each particle-size to the total emitted dusts is not related to wind speed and turbulence.
- Subject
- wind erosion; dust plume; dust sources; dust particle-size
- Identifier
- http://hdl.handle.net/1959.13/1325457
- Identifier
- uon:25276
- Identifier
- ISSN:0197-9337
- Language
- eng
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