SCALE EXPERIMENTS ON AEOLIAN DEPOSITION AND EROSION PATTERNS CREATED BY BUILDINGS ON THE BEACH

Abstract

Worldwide, buildings are present at the beach and in the dunes for recreation or habitation. Their presence can affect the beach-dune development, because they affect the airflow and Aeolian sediment transport in their surroundings. This might eventually have repercussions for coastal safety. We start examining these effects by studying the local sedimentation and erosion patterns around buildings. Hereto, we placed scale models of buildings on the beach. The sedimentation and erosion patterns around the models were measured using structure-from-motion photogrammetry. In general, the air flow around bluff bodies like buildings forms a horseshoe vortex. This creates deposition and erosion patterns in a horseshoe shape. For nearly all scale models, the upwind part and downwind tails of the horseshoe showed deposition. The horseshoe deposition at the building sides was sometimes visible, also depending on building orientation. Frequently, smaller erosion and/or deposition areas also developed between the horseshoe deposition and the building.