Dr Joanna Bullard

M.A (Edinburgh), Ph.D. (Sheffield)

Reader in Aeolian Geomorphology

email: J.E.Bullard@lboro.ac.uk
Tel : +44 (0)1509 222792
Fax: +44 (0)1509 223930

Room NN.1.22, Martin Hall building, East Park

Research Interests

• geomorphic processes in dryland environments

• aeolian processes and landforms

• dust production and emissions

My research focuses on geomorphology and sedimentology in dryland environments, for which I have established an international reputation and recently been awarded the Philip Leverhulme Prize in the field of Earth, Ocean and Atmospheric Sciences and the Gordon Warwick Award (from the British Geomorphological Research Group).  It contributes to debates concerning, and our understanding of, the response of dryland systems to climate fluctuations and the potential importance of aeolian processes to global biogeochemical cycles.  The majority of my field research has been conducted in southern Africa and Australia with additional projects in the USA and the UK.


Current Research Projects

The rate and nature of fine particle (<63mm) production by aeolian abrasion

Contemporary natural sources of fine particles (<63mm) include sandy soils and dune sands.  Previous work concludes that aeolian abrasion of these sediments will not yield significant amounts of fine material, however the close spatial relationships between major dust storm regions and sand seas suggest that the mechanism should not be discounted.  This project is using series of experiments to evaluate the potential for aeolian abrasion of natural dune sands to produce fine particles.  Whilst one mechanism of fine particle production (chipping and spalling) is widely-recognised in existing literature, a second – the removal of iron oxide rich clay coatings – has been identified through this work and quantified for the first time.  Quantifying the removal of these coatings from dune sands is particularly significant because, when removed, they comprise fine sediments (<4mm) which contribute to the atmospheric dust loading and play an important role in marine biological processes and soil nutrient balance.

Bullard, J.E. & White, K.H.  2002. Quantifying iron oxide coatings on dune sands using spectrometric measurements, an example from the Simpson-Strzelecki Desert, Australia. Journal of Geophysical Research-Solid Earth. 107 (B6) 2125 ECV 5-1 – 5-11.

Bullard, J.E., McTainsh, G.H. & Pudmenzky, C. 2004. Aeolian abrasion and modes of fine particle production: an experimental study.  Sedimentology. 51, 1103-1125.

Bullard, J.E. & White, K.H. 2005. Dust production and the release of iron oxides resulting from the aeolian abrasion of natural dune sands. Earth Surface Processes and Landforms. 30, 95-106.

Bullard, J.E., McTainsh, G.H. & Pudmenzky, C. 2007.  Factors affecting the rate and nature of fine particle production by aeolian abrasion.  Sedimentology. 54, 1169-182.

White, K.H. & Bullard, J.E. forthcoming. Abrasion control on dune colour: Muleshoe Dunes, SW USA.  Earth Surface Processes and Landforms.


Identifying sub-basin scale aeolian dust sources in Australia

All major dust source regions are inland drainage basins with annual rainfall <250 mm that experience intermittent flooding that produces extensive alluvial or playa lake deposits. Generalised evidence is available to support this contention, however more detailed wind erosion process studies show that a significant proportion of the dust may come from relatively small source areas. Most inland basins are patchworks of soil and land types that yield not only different quantities, but also different types, of dust.  This project assesses the relative importance of different land types as dust sources within an inland basin.

Bullard, J.E., Baddock, M.C., McTainsh, G.H. & Leys, J.F. in prep.  Sub-basin scale dust emissions – geomorphology and landscape controls.  To be submitted to Earth Surface Processes and Landforms.

Baddock, M.C., Bryant, R., Bullard, J.E. submitted. Detecting dust sources using MODIS imagery: a comparison of techniques.  Remote Sensing of the Environment

MODIS image of dust plume in central Australia

Proglacial dust emissions

Cold climate aeolian processes and landforms are widely recognised but receive little attention.  They are, however, likely to become increasingly important in zones of climate-driven ice retreat. Sediment supply in proglacial areas is strongly influenced by meltwater activity and improving understanding of cold climate aeolian processes and landforms, including sand dune and loess formation as well as the input of fine dusts to the atmosphere, requires an integrated study of glacifluvial and aeolian systems.  The overall aim of this research is to improve our understanding of the relationship between glacifluvial and aeolian processes in proglacial areas, through establishing the spatial and temporal patterns of sediment delivery from a glacier to its forefield and the sediment exchanges that take place between the glacifluvial and aeolian systems, therefore producing a combined glacifluvial-aeolian sediment budget.  The current geographical focus of this work is West Greenland.

Dunefield in Sandflugtdalen, West Greenland

Monitoring aeolian sediment transport, West Greenland

Bullard, J.E. & Austin, M. Contemporary proglacial aeolian sediment transport in West Greenland. Paper presented at the AGU Fall Meeting, San Francisco, 10-14 December 2007.  Download abstract (PDF).

Austin, M. & Bullard, J.E. Variation and Distribution of Sediments in a Mixed Glacifluvial-Aeolian System in West Greenland. Paper presented at the AGU Fall Meeting, San Francisco, 10-14 December 2007.  Download abstract (PDF).


Dunefield evolution and environmental change in northern Chile

The Atacama Desert is the driest hot desert on Earth.  The large-scale geomorphological characteristics of the Atacama preclude the development of extensive sand seas such as those found in southern Africa or the Middle East, however there are numerous small dunefields that have developed and these have been largely neglected by geomorphologists.  My current research in the Atacama focuses on three dunefields at approximately the same latitude, but at very different altitudes and with different sediment supply histories.

Huasca dunefield, east Chile

Coastal dunefield, west Chile

Bullard, J.E. in prep. Sedimentology and geomorphology of the Yape dunefield, north Chile.  To be submitted to Sedimentology.

Bullard, J.E. & Nash, D.J. in prep. Topographic controls on aeolian deposition: examples from the central Atacama Desert, north Chile.  To be submitted to Geomorphology.


Aeolian-fluvial interactions in dryland environments

I have been working on the relationship between aeolian and fluvial systems in dryland environments, in their broadest sense, for nearly ten years.  This has included a major NERC-funded project investigating the interactions between valley topography and aeolian sediment dynamics as well as numerous smaller projects.

Image 7: Valley-marginal sand deposits, central Namibia

Bullard, J. E. & Nash, D. J. 1998. Linear dune pattern variability in the vicinity of dry valleys in the southwest Kalahari.  Geomorphology. 23: 35-54.

Bullard, J.E., Wiggs, G.F.S. & Nash, D.J. 2000. Experimental study of wind directional variability in the vicinity of a model valley.  Geomorphology, 35: 127-143.

Bullard, J.E. & Nash, D.J. 2000. Valley-marginal sand dunes in the southwest Kalahari: their nature, classification and possible origins Journal of Arid Environments, 45 (4): 369-383.

Bullard, J.E. & Livingstone, I. 2002. Interactions between aeolian and fluvial systems in dryland environments. Area. 34: 8-16.

Wiggs, G.F.S., Bullard, J.E., Garvey, B. & Castro, I. 2002. A preliminary field study of interactions between airflow and valley topography with implications for aeolian sediment transport.  Physical Geography, 21, 5, 366-380.

Bullard, J.E. & McTainsh, G.H. 2003. Aeolian-fluvial interactions in dryland environments: scales, concepts and Australia case study. Progress in Physical Geography, 27, 471-501.

Bourke, M., Bullard, J.E. & Barnouin-Jha, O. 2004. Aeolian sediment transport pathways and aerodynamics at troughs on Mars.  Journal of Geophysical Research – Planets. 109, E07005, DOI.10.1029/2003JE002155.

Garvey, B. Castro, I.P., Wiggs, G.F.S. & Bullard, J.E. 2005.  Measurements of flow over isolated valleys.  Boundary-Layer Meteorology, 117: 417-446.

Bullard, J.E., McTainsh, G.H. & Martin, P. 2007.  Establishing stage-discharge relationships in multiple-channelled ephemeral rivers: a case study of the Diamantina River, Australia.  45, 3, 233-245.


Undergraduate Teaching

Year 1  Earth Systems Science Practising Geography

Year 2  Geographical Concepts & Designs Earth Surface Processes and Landforms

Year 3  Aeolian Processes and Landforms