Seasonal Variations of Saltation Activity on A High Plains Saline Playa: Yellow Lake, Texas

Abstract

The Southern High Plains region of West Texas and eastern New Mexico is often described as a flat elevated tableland. Spaced across this vast and otherwise featureless plain are 21 large closed basins containing approximately 40 irregularly shaped saline playas. Yellow Lake, located on the Yellow House Ranch northwest of Lubbock, Texas, is among the largest of the High Plains saline playas. This paper represents the first report of a 4-yr. study of saltation activity at Yellow Lake. From December 30, 1998, to January 1, 2003, a fast-response piezoelectric saltation sensor was used to collect a continuous record of aeolian activity at a point on the playa surface. Since saltation activity is often associated with dust emissions, the saltation record also provides information regarding seasonal patterns of dust emissions from the Yellow House Basin. Results suggest that blowing events can occur at any time of the year when conditions are favorable; however, the necessary conditions are rarely satisfied. As a result, the saltation record is characterized by many hours of inactivity punctuated with brief periods of occasionally intense aeolian activity. From December 30, 1998, to January 1, 2003, saltation activity was detected for only 7% of the hours measured. Although there can be substantial deviations from one year to the next, it was found that saltation activity tends to peak during winter months when winds are moderately strong and precipitation is at a minimum. Hourly saltation activity values occasionally approached unity during intense winter blowing events, indicating nearly continuous sediment transport over a one-hour period. Saltation activity is at a minimum during summer months when winds are often weak and wet conditions prevail. Although winds are typically strongest during the spring season, the playa is relatively stable due to high threshold values produced by significant spring precipitation. This contrasts sharply with the surrounding cropland, which tends to be most active during the spring season.

Keywords:

• playa
• deflation
• saltation
• aeolian
• dust
• Southern High Plains