A modelling platform for complex socioecosystems: an application to freshwater management in coastal zones

Providing deliberation support tools for freshwater management in coastal zones requires complex socio-ecosystem modelling in a joint effort from research scientists, software engineers and stakeholders. The SPICOSA System Approach Framework provides guidelines for the building of dynamic models for a better comprehension of the variety of processes and issues regarding coastal management. A modular platform was developed using the ExtendSim® software. We explore how the SPICOSA/Extend platform supports participatory modelling by offering the necessary tools for the integration of multidisciplinary knowledge and how the use of a common platform facilitates dialog between research scientists of varied backgrounds. Graphical tools developed in ExtendSim allow for a synthetic and user-friendly representation of the system processes and, in particular, of performances of management options in prospective scenario simulations. We discuss how an economical and social approach of the issues influences the choice of processes and variables to be modelled as well as the level of complexity needed to represent the ecological and physical system. The illustration of this approach will be supported by two case studies. The first concerns the freshwater use competition in the Charente River on the French Atlantic coast. The second refers to water quality management applied to micro-biological contamination from watershed runoff in the Thau lagoon on the French Mediterranean coast.