|Arimoto, Richard - NMSU CARLSBAD|
Submitted to: Journal of Arid Environments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 6, 2010
Publication Date: November 1, 2010
Citation: Stout, J.E., Arimoto, R. 2010. Threshold wind velocities for sand movement in the Mescalero Sands of southeastern New Mexico. Journal of Arid Environments. 74(11):1456-1460. Interpretive Summary: Threshold is an important parameter in wind erosion research. Under naturally turbulent wind conditions, wind gusts may intermittently exceed threshold, producing bursts of blowing soil and dust leading to topsoil loss, and a host of other environmental problems. Recently, a new technique was developed that provides a practical method for establishing the critical threshold of an erodible surface under natural wind conditions using a sampling system that continuously collects wind data along with critical information regarding wind erosion activity. To further test the new method and determine its usefulness, a field experiment was performed at two sites within a rangeland setting in the Chihuahuan Desert near Carlsbad, New Mexico. Results indicate that threshold could be measured at both locations simultaneously and that threshold values were of a similar magnitude at both sites with an average of around 10.8 m/s at Near Field and 10.5 m/s at Gnome.
Technical Abstract: Wind erosion activity was studied at two Chihuahuan Desert sites, the Gnome site which was contaminated with radioactivity from a nuclear device in 1961 and Near Field, a reference site. Saltation activity was measured with piezoelectric sensors, and those data were used to calculate threshold wind speeds for particle production. Significant blowing events were observed on only nine days of the 114 day study, and active transport was never observed during more than half of any 5-min sampling interval. Blowing events were most common in the late morning to mid/late afternoon, and average threshold values exceeded 10.5 m/s at both sites, which is about twice those measured previously at the Morgenstern sand dunes; this difference can be explained by the more abundant vegetation at the Chihuahuan sites. Less saltation activity occurred at the Gnome Site compared with Near Field, especially during April; and while this can be attributed primarily to differences in wind speed and threshold, wind strength alone does not control particle production. Additional studies are needed to evaluate other potentially important controlling factors such as relative humidity and solar insolation, but the results demonstrate the feasibility of the methods for studying wind erosion in environments with vegetative cover.