|RAVI, SUJITH - Stanford University|
|SANKEY, JOEL - Us Geological Survey (USGS)|
Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: 12/3/2012
Publication Date: 12/7/2012
Citation: Ravi, S., Zobeck, T.M., Sankey, J.B. 2012. Post-disturbance dust emissions in dry lands: the role of anthropogenic and climatic factors[abstract]. American Geophysical Union Fall Meeting. December 3-7, 2012. San Franciso, California.
Technical Abstract: Disturbances, which cause a temporary reduction in vegetation cover, can greatly accelerate soil erosion by wind and subsequent dust emissions from desert grasslands and shrublands. These ecosystems worldwide are threatened by contemporary shifts in vegetation composition (e.g. encroachment by shrubs, invasion by exotic grasses) and climatic changes (e.g. increase in aridity, droughts), which alter the frequency and intensity of disturbances and dust emissions. Considering the deleterious impact of dust-borne contaminants on regional air quality and human health, accelerated post-disturbance aeolian transport is an increasingly serious concern for ecosystem management and risk assessment. Here, using extensive wind tunnel studies, field experiments (in grasslands and shrublands of North America) and modeling, we investigated the role of disturbances (fires, grazing) and changes in hydroclimatic factors (air humidity, soil moisture) in altering aeolian processes in desert grassland and shrublands. Our results indicate that the degree of post-disturbance aeolian transport and its attenuation with time was found to be strongly affected by the antecedent vegetation type and post-disturbance climatic conditions. The interactions among sediment transport processes, disturbances and hydroclimatic factors are explored from patch to landscape scales and their roles in dust emissions and land degradation are discussed.