A case study of environmental modelling and simulation using transplantable components

Recent changes in environmental modelling practice have included adoption of modern software engineering concepts of model reuse, extensibility and flexibility, and development of better visual user interfaces. Additionally, the concepts of component-based software development and use of object-oriented programming have produced new environmental modelling methods. These changes have been supported by development of a range of modelling environments that allow rapid creation of environmental models from components. To date there has been little exploration of the opportunities that modelling environments offer in terms of flexible model construction by transplanting components. In the work reported here, simple catchment-based nonpoint source pollution models are constructed using the ICMS modelling environment, and a number of different data types and components are used within a single model structure to estimate pollution loads. Models include a bulk runoff-concentration load calculation, an export coefficient model, and land-use specific runoff and loads. It was found that, when applied using a powerful and flexible modelling environment, the component-based modelling concept provides not only an elegant method for model development, but also the opportunity to explore model expansion and refinement through use of transplantable components.