PM10 Emission, Sandblasting Efficiency and Vertical Entrainment During Successive Wind-Erosion Events: A Wind-Tunnel Approach

PANEBIANCO, J. E.; MENDEZ, M.J,; BUSCHIAZZO, D.E.

BOUNDARY-LAYER METEOROLOGY

SPRINGER

Año: 2016

0006-8314

A wind-tunnel experiment was carried out to measure saltation and PM10 emission during three successive wind - erosion events on three different surfaces: an unpaved road (UR) and two different textured agricultural soils: a sandy loam (SL) and a loamy sand (LS). The total horizontal mass transport (Q) and the PM10 emissions (E), were measured at two friction velocities: 0.2 m s-1 and 0.3 m s-1. Results indicated that Q decreased rapidly in time over all surfaces, as the Q values were only 13 to 17 % of the amount registered during the first events. Similar trends were detected at both wind speeds. However, E values showed a lower relative decrease in the second wind - erosion event at the lower wind speed (25 to 51 % of the initial amounts) than at the higher wind speed (19 to 28 % of the initial amounts) over all surfaces. After the second wind erosion event, both Q and E values remained constant except for the unpaved road, where both decreased by 50 % in relation to the second event. Emission from the agricultural soils was sustained over successive wind - erosion events even when saltation was low. The sandblasting efficiency for PM10 emission was found to be higher for agricultural soils than for the unpaved road, and increased over wind erosion events particularly in agricultural soils, and this was also reflected in the PM10 vertical entrainment. Results suggest that sandblasting efficiency and PM10 vertical distribution can change among wind erosion events even for the same surface. The saltators to PM10 content ratio can be a simple indicator of the general behaviour of an emitting surface during successive wind erosion events.