- Flexsem is a modular, fast and user friendly framework for 3D modelling in estuaries.
- User defined equations and unstructured computational mesh make it very flexible.
- Simplified hydrodynamics provides realistic solutions for estuarine systems.
- Flexsem is highly suitable for important questions related to coastal management.
Ecological modelling: essential tool for ecosytem-based management
The multiple hydrodynamic and ecological processes characterizing estuarine systems make ecological modelling an essential tool for ecosystem-based management by increasing the understanding of the complex interactions and by quantifying the effects of various natural and anthropogenic pressures.
The modelling technique used is dominated by computational simple box model approaches with a low spatial resolution and coupled 3D hydrodynamic-ecological models with high computational requirements.
Knowledge acquired through Flexsem contributes important information to decision support tools to facilitate the implementation of measures to improve water quality and good environmental status, not least important in the Baltic Sea Action Plan.
Novel framework for modelling in estuaries
In this paper we present a novel concept (Flexsem: FLEXible Simulation and Ecological Modelling) which combines the computational simplicity and condensed hydrodynamics from box models with a high spatial resolution characterizing coupled 3D models.
The modelling framework Flexsem is a fast, flexible and user-friendly tool specifically targeted towards scientific and management challenges of the complex biogeochemical processes in coastal zone ecosystems.
Flexsem has been developed as part of activities of the Baltic Nest Institute, linking processes acting on the local
scales of individual estuaries with sub-basin and intra-basin scales.
Simulating and reproducing physical conditions with Flexsem
We use Flexsem to simulate the physical conditions in a typical Danish estuary, Horsens Fjord utilizing unstructured computational meshes to vary the complexity of grid geometry and resolution.
The results showed that the model was able to reproduce the physical conditions in the estuary and provide reliable estimates for the tracer residence time.