Ostend-Middelkerke, monitoring of the dune for dike pilots in: Evolution after 2 years

At the beginning of 2021, the MDK Coastal Division, Ostend and Middelkerke built-up dunes on the dry beach in front of a sea dike at three locations: Spinoladijk (Ostend), Raversijde and Westende. Intensive monitoring at these sites was carried out from the beginning of 2021 to 03/2023 to investigate the development of the built dunes and to follow closely their morphology and planted vegetation. This report documents the 2nd year evolution of the morphology of the dune for dike pilots. A progre…

At the beginning of 2021, the MDK Coastal Division, Ostend and Middelkerke built-up dunes on the dry beach in front of a sea dike at three locations: Spinoladijk (Ostend), Raversijde and Westende. Intensive monitoring at these sites was carried out from the beginning of 2021 to 03/2023 to investigate the development of the built dunes and to follow closely their morphology and planted vegetation. This report documents the 2nd year evolution of the morphology of the dune for dike pilots. A progressive evolution of the three pilot sites occurred over the entire monitoring period. A substantial accretion took place in the 1st year in the zones where marram, fences were installed. Aeolian sand transport was captured to an extent thanks to them. However, sand gain was strongly reduced there over the 2nd year at the three sites. This was probably due to an obstruction by the formed dunes, higher marram grass plants, and a lower wind regime over this period. Also, there was a reduction of sand availability at Raversijde. Storm impact of 01/2022 and 09/2022 was relatively limited. Further monitoring surveys would help to understand the observed relationship between accretion in the upper-part of the dry beach and erosion dominating its lower part above the low water mark.