2.1 Context

As our understanding of the natural environment advances, the questions asked of environmental numerical models are rapidly increasing in breadth and complexity. Setting up, calibrating and executing defensible environmental models to assist in addressing such questions has therefore become an increasingly challenging proposition. This is particularly relevant with regard to whole-of-catchment studies where the linkage between catchment management intervention and associated receiving water changes is of increasing interest (and complexity) within the environmental management space.

The architecture and functionality of TUFLOW CATCH has therefore been deliberately designed to assist environmental modellers in overcoming some of these challenges, and in doing so improve the efficiency and effectiveness with which numerical modelling can support longer term environmental management at the catchment scale. Importantly, TUFLOW CATCH’s architecture provides a mechanism by which users can seamlessly simulate hydrologic, hydraulic, pollutant export and transformative receiving water quality processes within one unified, automated and internally consistent framework. This deliberate design choice has been motivated by the observation that historically, catchment and receiving waterway simulations have often been undertaken using disparate modelling platforms not designed or intended to be linked, and that (more often then not) operate under materially different assumptions and levels of scientific rigour. One example of such an instance might be where predictions from a catchment model that uses average (spatially and temporally lumped) hydrology and event mean pollutant export assumptions are used to provide inflow boundary conditions to a fully three dimensional receiving water quality model that operates on a highly spatial and temporally resolved domain and makes limited average assumptions. TUFLOW CATCH exploits the latest compute power advances and scientific rigour to overcome such disconnects.

In short, TUFLOW CATCH has been designed to provide access to state of the art bottom-up environmental modelling science at the integrated catchment scale, without deploying top-down average assumptions. The core architecture that provides this easy access is described below, and the details of the methods deployed in supplementary processes such as geolocation are described in Sections 3.1 and 3.2. The associated simulation commands and execution approaches are provided in Sections 4 and 5, respectively.