OpenMI – Real Progress Towards Integrated Modelling

Abstract

The case for integrated catchment management has been well made and has become a core part of initiatives such as the EC Water Framework Directive. Most water and environmental professionals expect that integrated modelling will take a necessary role in decision support for catchment management, in both planning and operations. Indeed, there is a common assumption that such modelling exists and is regularly carried out. Yet a closer examination reveals that where model integration does exist, it is in a hard-wired or entirely proprietary way. The shining example is in the specialist and limited field of real-time flood forecasting, where there are some notable implementations of integrated modelling, albeit with many restrictions on the connections (or linkage) between models.

The widespread implementation of integrated modelling depends on the availability of a sufficiently flexible and powerful linkage mechanism for data exchange between models, and indeed between models and user interfaces, databases and other data-hungry processes. Until now, no such linkage has existed, and easy availability of integrated modelling has remained a dream. Under the EU Framework 5 HarmonIT Project, a remarkable collaboration between rival commercial software specialists, with the help of some excellent academic, research and operational partners, has developed the OpenMI standard for data interfaces. It is anticipated that this standard will have far-reaching consequences for modelling and for hydroinformatics in general.

An implementation of the standard has also been developed, along with sufficient utilities to allow the standard to be tested to the point of scientific proof or proof of concept. The main tests have involved the incorporation of the OpenMI data interface in a range of model source codes, from widely used commercial codes to specialist research models. Various combinations of populated models were then built and the data transfers tested.

This chapter presents an overview of the technical details of the OpenMI standard. It also briefly describes how existing modelling software can be made OpenMI-compliant. The full specification can be downloaded from the OpenMI-website www.openmi.org or can be downloaded from the documentation section of the OpenMI environment software installation package (including source code) available from the CVS repository on sourceforge.net/projects/openmi.

The authors acknowledge that the availability of a suitable integration mechanism is just the beginning. OpenMI now exists as a freely available, open-source standard, but its long-term future needs to be secured for it to have lasting impact on catchment management. Much research and development needs to be done to understand how best to implement integration between different sorts of models with a variety of linkages. Should we expect a major shift from single-issue modelling to integrated modelling? Does OpenMI offer new opportunities to modellers and to water managers? The authors expect that the answer to both questions is “yes”, but we will have to wait and see if OpenMI really does change modelling in practice.