Modelling framework for aquatic systems
Usually, this is done with the help of mathematical models and predictions. However, current models of aquatic systems are still approximations and there is no single best model that achieves the right balance of complexity, precision and ease of calibration. While the more complex models may deliver more exact results, they are also more difficult to understand. At the same time, less complex models often reduce uncertainty in predictions. A new modelling framework has now been developed by the ORFOIS project team to make it easier for ecologists to choose the right level of complexity for their models. It allows the creation of uni-dimensional water-column and sediment models. Their degree of complexity can range from simple nitrate-based ecosystem models to more complex simulations. The simpler models are based on nutrients, phyto-plankton, zooplankton and detritus (NPZD). The more complex models can combine unbalanced formulations for several groups of algae, dissolved organic matter (DOM) and particulate organic matter (POM) with balanced formulations for several groups of zooplankton. Two extensive manuals were published on the ORFOIS CD. The first one shows how to create uni-dimensional models within the framework. The second manual describes the various components incorporated in the framework. The uni-dimensional model framework was used to demonstrate the impact of a chosen model's complexity on the results of the simulation. The ORFOIS CD provides the data and software to show the results of these demonstrations on a PC.