E2 - A Flexible Framework for Catchment Modelling

Catchment management requires modelling for compliance, investigation, understanding, knowledge capture, and informing decisions. The nature of the problems is variable, ranging across scales both temporally and spatially, including discrete events, long term averages, daily and seasonal dynamics, point and spatial estimates and total catchment outputs. These requirements have spawned a variety of models over the years. Difficulties in model use are created when the problem situation changes, and a different question is being asked of a given model. Models with fixed algorithms and structures are not good at providing the flexibility that is often required as management needs change. To address this, a flexible modelling framework has been created, named E2. E2 is part of the Catchment Modelling Toolkit. It uses a robust conceptualisation of catchment processes, based around the notion of a catchment, made up of sub-catchments, wherein component models of different natural processes are positioned and linked to form a whole-ofcatchment model (Figure 1)