Digital landscape representation

Spatial models coupling

Modelling concepts

The OpenFLUID platform (Fabre et al., 2013 ; Fabre et al., 2010) is based on

  • a topological representation of space through connected spatial units,
  • a system for coupling models in space and time,
  • a monitoring system for simulations, in order to extract simulation data, controlling, …

The landscape space is represented as a set of spatial units. Each spatial unit represents one or more real landscape elements or sub-element, and holds relevant attributes associated to these elements (morphology, physical properties, …). The overall structure of the spatial area is managed using a graph (Rabotin et al., 2013), where the graph nodes are the spatial units and edges are the relations between these spatial units. Every node of the graph can also bring a sub-graph in order to represent different spatial scales.

The coupled model is a set of spatio-temporal models, coupled using the exchanged simulation variables. Every model declares the required input variables, the output variables it produces, and also the needed spatial attributes.

Software framework & simulators

The OpenFLUID software platform is mainly developped in C++. It is made of

  • the main software framework, providing functionalities for time and space management, for automatic coupling of models, for simulation monitoring,
  • software plugins integrating computational code of models to couple (simulators) and simulation observation methods (observers),
  • user interfaces.

The models are dynamically plugged to the platform as simulators (software plugins). A simulator integrates a computational code representing one or more spatial processes. The simulators are developed de novo or encapsulates existing codes. Every simulator declares a signature giving its inputs and outputs, the needed spatial attributes, the processed spatial units. This signature is automatically used by the framework of the platform in order to perform the coupling and control its consistency.

The simulators are developped in C++ or a compatible language (C, Fortran, …) using the dedicated development environment OpenFLUID-DevStudio.

The data produced during the simulations can be extracted by observers (software plugins) to various data format (csv, vtk, …) or to various graphical rendering softwares (GNUplot, GoogleEarth, …). The set of observers constitutes the simulation monitoring.

Workflow overview

Software applications, interfaces and bindings

OpenFLUID has various users interfaces.

  • The command-line interface proposes a simple usage for exuting simulations from an input dataset. It is also dedicated to batch usage or on a compute cluster.
  • The graphical interface (OpenFLUID-Builder) proposes an easy environment for preparation, parameterization, execution of simulations and access to results
  • The ROpenFLUID package allows parameterization and management of simulations from the environment for statistical computing, and thus offers many possibilities for models exploring : sensitivity analysis, propagation of uncertainty, …

So, users can benefit of a complete environment, and can focus on using or developing models for their simulations.

Also, the OpenFLUID software architecture offers the possibility to third-party developers to build their own user interface.

Share and collaborate

The OpenFLUID platform can also be used as a support for collaborative works involving modelling of complex landscapes. It makes easier the development, the capitalization, the sharing and reuse of models as simulators, inside workgroups, scientific research teams, collaborative networks, …

Collaborative work