Impact of Beach Surface Moisture on Aeolian Sand Transport Rate and Vertical Mass Flux Distribution, the Case of Atlantic Coast, Southern Morocco

The aeolian erosion and deposition patterns in vegetated areas are strongly influenced by the type of flow regime, which in turn depends on several factors including plant distribution, morphology, and density (see Hesp et al., 2019 for review). In the case of beach-dune systems, it is widely accepted that vegetation causes a reduction of wind velocity and acts as a trap of sand transported by the wind promoting accretion or dune growth (e.g.,

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“…31°). Both the beach and foredune are composed of fine to medium quartz sand with a mean grain size of 0.26 mm (Rotnicka, 2013a).…”

Section: Study Areamentioning

confidence: 99%

Skimming Flow and Sand Transport Within and Above Ammophila (Marram) Grass on a Foredune

et al. 2023

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“…The total sand transport rate was measured by means of 0.5 m high passive sand traps composed of a steel casing and removable plexiglass catcher divided into 40 cells, each 1.27 cm high and 1 cm wide (Figure 4b; Rotnicka, 2013aRotnicka, , 2013bRotnicka et al, 2023). The trap design allows for continuous accumulation of sand transported to a height of 0.5 m, and its efficiency has been estimated for medium sand at 82% regardless of wind speed.…”

Section: Experimental Setup and Measurementsmentioning

confidence: 99%

Airflow Dynamics and Aeolian Sand Transport Across a Beach‐Climbing Dune‐Clifftop Dune System

Dłużewski,

Rotnicka,

Hesp

et al. 2023

JGR Earth Surface

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This study presents an analysis of wind flow and sediment transport from the beach up a 50 m high, long (130 m), steep (mean slope 26°) climbing dune and across a 1.5 m high max, 85 m long and 17.5 m wide clifftop dune 30 km south of Dakhla in Morocco, NW Africa, during highly oblique incident wind conditions. Multiple 2D sonic and cup/vane anemometers and sand traps were utilized for measurements. Flow steering was significant on the upper climbing dune. Flow deceleration occurred near the dune toe, and topographic forcing of flow was considerable on the upper slopes of the climbing dune. Near‐surface flow steadiness (CVU1, CVU0.25) on the climbing dune straight slope segment was low and constant. The distance upslope over which the airflow reached a speed comparable to that on the beach increases as the incident wind speed increases. The greatest flow acceleration and speed‐up was observed at the cliff edge reaching 250% at 1 m height and 220% at 0.25 m height for the lowest incident wind speed class (4–5 m/s). The sand transport rate declined from the beach to the climbing dune toe and lower slope, but at the uppermost section of the climbing dune was 4 times higher than in the beach for the 7–8 m/s incident wind speed. Sand in aeolian transport was generally finer than surface sand, with the mean grain size increasing up the slope. A comparison of the sand transport data collected with sand transport models, and the effects of slope on Aeolian transport are also examined.

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Impact of Beach Surface Moisture on Aeolian Sand Transport Rate and Vertical Mass Flux Distribution, the Case of Atlantic Coast, Southern Morocco

Cited by 2 publications

References 9 publications

Skimming Flow and Sand Transport Within and Above Ammophila (Marram) Grass on a Foredune

Skimming Flow and Sand Transport Within and Above Ammophila (Marram) Grass on a Foredune

Airflow Dynamics and Aeolian Sand Transport Across a Beach‐Climbing Dune‐Clifftop Dune System

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