An integral approach to design the Roggenplaat intertidal shoal nourishment

• Published in: Ocean & coastal management 2019-04, Vol.172, p.30-40
• Main Authors: van der Werf, J.J., de Vet, P.L.M., Boersema, M.P., Bouma, T.J., Nolte, A.J., Schrijvershof, R.A., Soissons, L.M., Stronkhorst, J., van Zanten, E., Ysebaert, T.
• Format: Article
• Language: English
• Subjects: Estuarine management; Intertidal shoal; Morphological modelling; Sediment nourishment design
• ISSN: 0964-5691; 1873-524X
• DOI: 10.1016/j.ocecoaman.2019.01.023

The Eastern Scheldt, a tidal basin in the southwest of The Netherlands, underwent large physical and ecological changes due to a system-wide human interference. The construction of a storm surge barrier at the seaward side and closure of the upstream branches in the 1980s resulted in intertidal flat erosion. This has far reaching consequences for the ecological functioning of these habitats, especially as foraging ground for many wader species. Therefore, a 1.3 million m3 sand nourishment is foreseen on the Roggenplaat intertidal shoal to mitigate the erosion and preserve suitable foraging habitat for waders for the coming 25 years. This paper presents an integral nourishment design approach. It consists of the following steps: (i) understanding the morphology and ecology, (ii) translation of the nourishment objective into an evaluation framework, (iii) construction of a suitability map indicating potential nourishment locations, (iv) generation of nourishment designs, (v) short-term morphodynamic numerical model simulations, (vi) estimation of the long-term shoal development using a simplified approach, (vii) integral evaluation leading to the preferred design. This integral approach resulted in a design that is expected to fulfill the Roggenplaat nourishment objective, accounting for ecological, morphological, economical and technical aspects. This integrated approach could form a basis for future intertidal shoal nourishment designs worldwide. •We present an integral approach for designing intertidal shoal nourishments.•We demonstrate this approach for the Roggenplaat intertidal shoal in the Eastern Scheldt, The Netherlands.•This integrated approach could form a basis for future intertidal shoal nourishment designs worldwide.