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Submitted to: ASAE Annual International Meeting
Publication Type: Proceedings Publication Acceptance Date: 6/3/2001 Publication Date: N/A Citation: N/A Interpretive Summary: As we head into the 21st century, it is only natural that we ask whether progress has been made in reducing wind erosion of agricultural lands during the past century. One method of monitoring changing wind erosion patterns is to set up numerous single-field experiments where soil loss is measured directly with sediment samplers. To monitor wind erosion over a large region in this way is not practical. A simpler alternative is to us dust measurements as a surrogate for direct measurements of wind erosion processes. It is well known that wind erosion produces dust and, within remote agricultural regions that lack other significant sources of particulate matter, dust levels are often positively correlated with regional wind erosion activity. Thus, tracking dust concentration over a long period can provide a valuable record of long-term variability in wind erosion activity. Recent dust measurements obtained over a two-year period dby the USDA-Agricultural Research Service provide data necessary to compar present dust levels with those taken from 1961 to 1982. The results indicate a significant and continuing reduction of regional dust levels over the past four decades within the Southern High Plains. One can interpret this downward trend as an indication that wind erosion activity is decreasing in frequency and intensity in the Southern High Plains. Technical Abstract: In the semiarid Southern High Plains of North America, elevated dust levels are almost always associated with regional wind erosion events. Thus, measurements of atmospheric dust concentration provide an indirect measure of wind erosion activity within the Southern High Plains. In the Lubbock, Texas area, various government programs have provided funding for the measurement of total suspended particulates (TSP) from 1961 to the end of 1982. Changes in environmental law brought an end to the measurement of TSP due to a shift in the regulatory focus toward particulate matter with a median diameter less than 10 microns (PM_10). This sudden change disrupted a potentially valuable long-term TSP dust record. Recent TSP measurements obtained over a two-year period by the USDA-Agricultural Research Service provide data necessary to compare present dust levels with those taken from 1961 to 1982. The results indicate a continuing reduction of TSP over the past four decades which suggests a substantial decrease in wind erosion activity within the Southern High Plains. |
