ARS | Publication request: ENHANCEMENT OF WIND EROSION BY FIRE-INDUCED WATER REPELLENCY IN SOILS: A WIND TUNNEL STUDY.

Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: December 5, 2005
Publication Date: December 5, 2005
Citation: Ravi, S., D'Odorico, P., Herbert, B., Zobeck, T.M., Over, T. 2005. Enhancement of wind erosion by fire-induced water repellency in soils: a wind tunnel study[abstract]. American Geophysical Union. Paper No. B41D-0233.

Technical Abstract: Wind erosion and fire occurrences are known to affect the composition and structure of vegetation in dryland landscapes. Fires contribute to determine the dominance or co-dominance of woody plants and grasses in arid and semiarid ecosystems. Fires expose the soil surface to the erosive action of wind and also make the soil more erodible by the effect of the release of water repellent compounds from vegetation due to burning. Despite the relevance of wind erosion and fires to the dynamics of arid ecosystems, the interactions between these two processes remain poorly understood. Here by a series of wind tunnel experiments, laboratory methods and theoretical analysis, we investigate the effect of fire-induced water repellency on the soil susceptibility to wind erosion. The experiments were done using pure Ottawa sands which were artificially coated with palmitic acid, a common water repellent compound in soils. The results indicate that fire-induced water repellency enhances soil erodibility, causing a drop in wind erosion threshold. The results are explained by the effect of water repellent compounds on soil-water contact angle and on the strength of interparticle wet-bonding forces.