The architecture of the E2 catchment modelling framework

Catchment management is becoming a more complex task. The sharing of water resources between traditional water users and the environment, the introduction of water and contaminant trading and water quantity and quality targets has necessitated a whole-of-catchment modelling approach. A variety of software products address this need. They range from abstract, general-purpose modelling frameworks which are not tailored to catchment modelling, to software that is applicable only to a specific catchment. Many of these catchment models are ?hardwired? with algorithms that may not be appropriate for another catchment, or do not allow for the reuse of prior modelling knowledge. E2 is a catchment modelling framework within the Cooperative Research Centre for Catchment Hydrology (CRCCH) Catchment Modelling Toolkit. It allows the integration of components and models from other Toolkit products, and is designed to enable flexibility in model choice. The core capabilities of the framework extend beyond the modelling of physical processes in unregulated catchments, and the architecture was designed from the ground up to also enable the representation of regulated systems and ecological responses to physical conditions.