Elevated aeolian sediment transport on the Colorado Plateau, USA: The role of grazing, vehicle disturbance, and increasing aridity

Dryland wind transport of sediment can accelerate soil erosion, degrade air quality, mobilize dunes, decrease water supply, and damage infrastructure. We measured aeolian sediment horizontal mass flux (q) at 100 cm height using passive aspirated sediment traps to better understand q variability on t...

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Veröffentlicht in:Earth surface processes and landforms 2018-11, Vol.43 (14), p.2897-2914
Hauptverfasser: Nauman, Travis W., Duniway, Michael C., Webb, Nicholas P., Belnap, Jayne
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Sprache:eng
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Zusammenfassung:Dryland wind transport of sediment can accelerate soil erosion, degrade air quality, mobilize dunes, decrease water supply, and damage infrastructure. We measured aeolian sediment horizontal mass flux (q) at 100 cm height using passive aspirated sediment traps to better understand q variability on the Colorado Plateau. Measured q ‘hot spots’ rival the highest ever recorded including 7,460 g m−2 day−1 in an off‐highway vehicle (OHV) area, but were more commonly 50‐2,000 g m−2 day−1. Overall mean q on rangeland sites was 5.14 g m−2 day−1, considerably lower than areas with concentrated livestock use (9‐19 g m−2 day−1), OHV use (414 g m−2 day−1), and downwind of unpaved roads (13.14 g m−2 day−1), but were higher than areas with minimal soil disturbance (1.60 g m−2 day−1). Rangeland q increased with increasing annual temperature, increased winds, and decreasing precipitation. Spatial modeling suggests that ~92‐93% of regional q occurs in rangelands versus ~7‐8% along unpaved roads. Four of the five largest road q values (n=33) measured were along roads used primarily for oil or gas wells. Our findings indicate that predicted future mega‐droughts will increase q disproportionately in disturbed rangelands, and potentially further compromise air quality, hydrologic cycles, and other ecosystem services. Published 2018. This article is a U.S. Government work and is in the public domain in the USA. Wind‐blown sediment monitoring and spatial modeling show that more aeolian transport occurs on rangelands than unpaved roads due to the large aerial extent of rangelands, widespread grazing, and off road vehicle use (OHV). Hotter, drier, and/or windy seasons were also associated with elevated aeolian transport in rangelands suggesting that predicted future droughts could further increase transport.
ISSN:0197-9337
1096-9837
DOI:10.1002/esp.4457