The final objective of the DITTY project is to develop a prototype of a Decision Support System (Work Package 8) for the management of coastal lagoons, but besides this objective and linked to it, the DITTY project proposes the development of various tools as data collecting and data base (WP1-2), GIS tool (WP3), Numerical Models (WP4), Indicators and Benchmarking (WP5) and Economic tools (WP7).
Workpackage 4 provides a general modelling framework with implementation of different modelling modules able to describe the system components, i.e. lagoon, river basin and coastal waters, as well as the ecosystem functioning and the hydrodynamics. These models have been developed and implemented at each test site according to their specific characteristics, data availability and defined end-users scenario analysis and case studies. The approach have consisted of using already developed parts, when available, and developing/implementing a shared modelling approach for the non existing models. Each model, watershed, hydrodynamic or biogeochemical has been calibrated separately. Finally, the coupling between watershed model and lagoon model (hydrodynamic and biogeochemical parts) provides an integrated representation of the entire watershed-coastal lagoon ecosystem and allows scenarios simulations. The model outputs are then used to compare site responses and calculate water quality indicators and, linked to the economic indicators, become the inputs for the Decision Support System.
In practice, the modelling activity started in august 2003 and lasted 18 months. Six meetings and regular mail exchanges have allowed to share modelling development.