|Van Pelt, Robert - Scott|
|Scott, Russell - Russ|
Submitted to: Aeolian Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/14/2011
Publication Date: 4/5/2011
Citation: Zhang, Y., Nearing, M.A., Liu, B.Y., Van Pelt, R.S., Stone, J.J., Wei, H., Scott, R.L. 2011. Comparative rates of wind versus water erosion from a small semiarid watershed in southern Arizona, USA. Aeolian Research. 3:197-204. Interpretive Summary: In arid and semi-arid regions, both wind and water erosion can be serious land degradation processes, and may occur contemporaneously. Particularly where vegetation cover is sparse, rates of both water and wind erosion can be significant. Despite the potential importance of wind and water erosion in semi-arid environments, these two forms of erosion are usually studied as two separate processes. Meanwhile, the relative erosion rates of wind and water erosion have rarely been studied simultaneously and are poorly quantified. Thus total measured erosion losses by wind and water erosion are difficult to compare. In this study we developed a method for assessing net loss and gain by wind erosion and water erosion for a specified area so that net loss or gain of material within the control area due to wind and water could be directly compared. Wind-blown sediment fluxes were obtained around a semi-arid watershed boundary from March 2008 through June 2009. Meanwhile, runoff and sediment yields were measured at the outlet of watershed. We are able, therefore, for the first time to report relative rates of soil erosion, in the sense of net loss or gain per unit area, by wind and by water over the same area and same time period. The results of this research give us the capability to compare directly the significance of wind erosion and water erosion from a semi-arid rangeland watershed in southeastern Arizona. The measurements showed that sediment yield from the study area was significantly greater for water erosion compared to wind erosion. Our results showed that the net soil loss from wind erosion from the study area was not necessarily significant in the semiarid rangeland, southeastern Arizona USA.
Technical Abstract: Both wind erosion and water erosion can be serious land degradation processes in semi-arid dry-lands. However, the relative erosion rates of wind and water erosion have rarely been studied simultaneously and are poorly quantified. In this study, wind erosion and water erosion rates were simultaneously measured and compared over 15 months, which encompassed two spring, windy seasons, for a small rangeland watershed in the Santa Rita Experimental Range in southeast Arizona. Average sediment mass flux was 5.6 g m-1d-1. The net soil erosion balance rate by wind, as calculated by the net sediment fluxes leaving the study area, was 0.08 t ha-1 of soil loss for the study period, while the net sediment balance from water erosion was a factor of 180 times larger at 14.6 t ha-1. These results indicated that a) net soil erosion by water was much greater than that by wind for this area, and b) the net soil loss from wind erosion at the watershed scale was not represented by sediment flux measurements at the site.