SPITERI, C., VAN MAREN, B., VAN KESSEL, T and DIJKSTRA, J., 2011. Effect Chain Modelling to Support EMS-Dollard Managemnt. In: Micallef, A. (ed.), MCRR3-2010 Conference Proceedings, Journal of Coastal Research, Special Issue, No. 61, pp. 226–233. Grosseto, Tuscany, Italy, ISSN 0749-0208.

The Ems-Dollard estuary, located at the eastern side of the Dutch Wadden Sea, is influenced by conflicting human demands ranging from flood protection, shipping, ports and dredging activities, nature preservation, energy demands, fisheries, tourism and recreational activities. This combination of pressures jeopardizes the water quality and ecological functioning and demands for an integrated sustainable development plan.

As part of the strategic management plan for the area, a so-called effect chain modelling framework is being developed. This process-based approach combines biotic and abiotic processes, the main ecological components and the relevant anthropogenic demands. The integrated modelling framework is implemented in Delft3D (developed by former WL | Delft Hydraulics) and is composed of separate building blocks for hydrodynamics (Delft3D-FLOW) and sediment transport (Delft3D-SED), water quality (Delft3D-WAQ/BLOOM) and ecological dynamics (HABITAT) including interactions with higher trophic levels using a GIS-based spatial analysis tool. It allows for the quantification of the impact of a system component, parameter or process on the relevant ecological groups or processes within the marine environment. It results in an improved understanding of cause-effect relationships between the physical, natural environment and system stressors. The ultimate aim of the modelling framework is to develop a robust assessment tool for dealing with management questions related to site-specific issues, such as the relation between high turbidity and oxygen-depleted zones or the effect of nutrient inputs and dredging activities on water quality and habitat suitability.