Deposition patterns around buildings at the beach: Effects of building spacing and orientation

Airflow at the beach creates sand deposition patterns around buildings. To assess how initial deposition patterns depend on the orientation of a building relative to the wind direction and on the spacing between buildings, a series of one-day field experiments was conducted with cuboid scale models, in which 34 configurations were tested. Scale models placed further apart than 2 to 3 times the building width created deposition patterns that were similar to those for stand-alone buildings, where downwind deposition tails were the sum of the individual buildings' effects where these overlapped. For smaller spacings, between 0.5 and 2 times the building width, deposition patterns fundamentally differed from those for individual buildings, indicating a different type of airflow developed between the buildings. This created more complex depositional patterns that depended on the gap width. Rotation of an individual building relative to the wind direction induced an asymmetry in the downwind deposition patterns. A new rule of thumb quantitatively relates the asymmetry in the length of the deposition tails behind a building to the angle of the wind relative to the building and the length:width ratio of the building.