1.1 Context

TUFLOW CATCH enables the seamless bottom-up simulation of whole-of-catchment hydrologic, hydraulic, pollutant export and receiving waterway processes. It supports simulation of these processes from top of catchment to receiving waterway outlet via solution of the relevant equations of motion and transport, without recourse to lumped spatial or temporal assumptions. It draws on the power of GPU acceleration to explicitly simulate catchment water flow and pollutant processes in the surface and subsurface domains, and automatically reconfigures these predictions to drive downstream multidimensional receiving waterway hydrodynamic, sediment transport, water quality and other environmental models. This modern framework, that draws on advanced compute capability, allows environmental practitioners to holistically manage and understand catchments of interest and their receiving waters in an efficient, integrated and rigorous manner, without the need for manual model linking or reliance on top-down average assumption modelling techniques. TUFLOW CATCH’s design is flexible so as to support tailoring of its configuration to meet individual application demands, and as such allows for execution of multiannual studies such as (but not limited to):

• Seamless assessment of the impact of land use or other catchment based changes on the hydrodynamics of downstream receiving waterways (i.e. without the need to simulate pollutant export, see Section 1.3, bullet point 1)
• Assessment of the impact of land use or other changes on catchment hydrology and/or pollutant export (i.e. without the need to directly include receiving waterway numerical simulation, see Section 1.3, bullet point 2)
• Assessment of the efficacy of proposed catchment changes on downstream receiving riverine or estuarine health (i.e. fully integrated catchment and receiving waterway simulation of water flow and pollutant dynamics, see Section 1.3, bullet point 3)
• Assessment of the interaction of catchment inflows with water supply offtakes or other sensitive receptors
• Sediment and other pollutant export catchment dynamics investigations
• Various combinations of the above \(\newcommand{\blockindent}{\hspace{0.5cm}}\)