Seasonal sand transport through a trough blowout at Pinery Provincial Park, Ontario

Abstract

Trough blowouts represent transport pathways for sediment through coastal dune systems. This paper documents seasonal differences in sand transport through a trough blowout. Measurements were made by trapping sand in Rosen-style traps installed at the mouth and crest of the parabolic dune and with erosion pins in the throat. Erosion-pin data indicated that the surface of the dune was generally accreting in late summer and eroding in winter, suggesting that the major loss of sediment from the dune was occurring in winter. The traps were emptied every 2–4 weeks and showed that, in general, more sand left the dune system than entered it. The amount of sand transported past the traps at the mouth of the dune varied seasonally, with smaller amounts during the summer months than in winter. The upper traps showed greater variability, but had more sediment transported in all months when compared with the lower traps. Amounts of sand transported during winter were greater than in summer.

Origin and evolution of playas and blowouts in the semiarid zone of Tierra de Pinares (Duero Basin, Spain)

“…Jungerius et al (1981) identify an upper limit of 30 m in the length of the blowouts developed in the coastal dunes of The Netherlands. Several studies reveal seasonal variations in the activity of the blowouts showing a preferential growth during the dry season (Lancaster, 1986;Pluis, 1992;Byrne, 1997). The blowouts are commonly associated with parabolic dunes on vegetated sandy surfaces (Hack, 1941;Verstappen, 1968;Pye, 1982;Eriksson et al, 1989).…”

Airflow and sediment movement within an inland blowout in Hulun Buir sandy grassland, Inner Mongolia, China

“…Blowouts occur in both coastal and inland environments from low to high latitudes (Hesp, 2002;Dominguez and Barbosa, 2004;Hugenholtz and Wolfe, 2006;Wang et al, 2007), they commonly occur as depressions or hollows formed by aeolian erosion (Hesp and Hyde, 1996;Byrne, 1997;Hesp and Pringle, 2001;Hesp, 2002;Hugenholtz and Wolfe, 2006). Blowouts consist of two parts: a deflation basin and a depositional lobe, and they are classified into three categories based on their topographic shape: saucers, bowls, and troughs (Hesp and Walker, 2012;Smyth et al, 2013;Sun et al, 2015).…”

“…Spatial differences in sand transport influence the patterns of erosion and deposition within blowouts and play an important role in their morphological development. Sediment transport within blowouts has been measured using erosion pins (Jungerius et al, 1981;Jungerius and Meulen, 1989;Jungerius et al, 1991;Pluis, 1992;Byrne, 1997;Hugenholtz and Wolfe, 2009), sand traps (Gares, 1992;Byrne, 1997) and topographic surveys (Gares and Nordstrom, 1988;Käyhkö, 2007). However, only Smyth et al (2014) have measured sediment transport in relation to near surface wind speed within a coastal trough blowout; they found that where airflow was steadiest, sediment transport rate was greatest.…”

Dynamic Changes of Typical Blowouts Based on High‐Resolution Data: A Case Study in Hulunbuir Sandy Land, China

“…The shrubs also played a role in shunting wind-drift sands [16,17] so that the airflow moved forward towards the rear depression edge along the northern and southern slopes to undercut them, thereby continuously increasing the depression width (Figure 17(a)) [18]. The sand materials severely eroded the soil layer at the rear depression edge beginning at the stoss slope toe due to the effects of terrain uplift, compressed airflow, and continuously accelerating wind after drifting, causing the soil layer to move along the long axis of blowout [19,20]. The wind decelerated after reaching the stoss slope crest where sand materials were deposited.…”

“…Table 5 shows where the stoss slope toe of the blowouts moved forward by 1.0 m along the long axis of the depression due to wind erosion, with an annual mean movement of 0.5 m⋅a The transverse depression profiles (Figure 8) show where the northern and southern slopes of erosion depressions were asymmetrical. The northern slopes were relatively gentle (18)(19)(20) ∘ ), whereas the southern slopes were relatively steep (23-25 ∘ ). The depression bottoms were smooth.…”