INDIRECT EVIDENCE OF WIND EROSION TRENDS IN THE SOUTHERN HIGH PLAINS OF NORTH AMERICA

Authors: Stout, John; LEE, JEFF - TEXAS TECH UNIVERSITY

Submitted to: Journal of Arid Environments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/28/2002
Publication Date: 9/1/2003
Citation: Stout, J.E., Lee, J.A. 2003. Indirect evidence of wind erosion trends on the Southern High Plains of North America. Journal of Arid Environments. 55(1):43-61.

Interpretive Summary: Agricultural practices and land-use patterns tend to evolve as farmers react to economic forces, adopt new technologies, and adjust to varying climatic conditions. In the process an entire region can be gradually transformed. Such regional transformations can have positive or negative impacts on the wind erosion problem. We have managed to piece together evidence of declining wind erosion activity within the Southern High Plain over the latter half of the 20th century. During this same period, there have been no appreciable climate shifts that can account for the observed declines in blowing dust and wind erosion activity during the last half century. One is left to conclude that the Southern High Plains has been gradually transformed by improvements in agricultural practices and that the collective actions of individual farmers have had the net effect of significantly reducing wind erosion rates and dust emissions during the latter half of the 20th century.

Technical Abstract: Farmers are continually adjusting their agricultural practices and collectively they gradually modify regional land-use patterns. As semi-arid regions, such as the Southern High Plains (SHP), are transformed one expects that it should be possible to detect related changes in regional wind erosion activity. Here we attempt to piece together indirect evidence of changing wind erosion patterns. Indirect evidence includes visibility- based observations of blowing dust and measurements of ambient particulate matter concentration. In the mostly rural SHP there are few significant industrial sources of particulate matter so that elevated ambient levels usually indicate blowing dust associated with regional-scale wind erosion activity. Both visibility-based surface observations of blowing dust and direct measurements of particulate matter concentration suggest independently that there have been significant declines in blowing dust during the last half century. There have been no appreciable climate shift in the SHP that could account for the observed decline in blowing dust. Nor can it be argued that declines in airborne particulate matter concentration are solely due to air pollution controls placed on motor vehicles and industry. One is left to conclude that during the latter half of the 20th century, the SHP has been gradually transformed by improvements in agricultural practices and that the net effect has been a reduction in wind erosion and associated dust emissions.