Accurate and timely flood inundation maps are highly desired for emergency response planning and to inform decision makers during major flood events. Hierarchical modeling frameworks consisting of multiple process-based weather, hydrologic and hydraulic models can be an ideal approach to simulate high resolution inundation maps. While such frameworks have been developed and implemented at small to medium scales, large-scale inundation mapping is often unattainable due to high computation costs associated with 2D hydrodynamic inundation models. 

To this end, we present a new open source multi-GPU accelerated 2D flood model called TRITON (Two-dimensional Runoff Inundation Toolkit for Operational Needs, https://code.ornl.gov/hydro/triton) that may help resolve this challenge. TRITON utilizes digital elevation data directly as the computational mesh and provides solution to the full 2D shallow water equations with source terms using an explicit first order upwind finite volume scheme. While TRITON can operate on several configurations including single or multi CPUs or GPUs, the use of multi-GPU enables large-scale and high-resolution simulation in a reasonable timeframe. Using local runoff and upstream streamflow as inputs, TRITON can be configured to study both pluvial and fluvial flood events. We demonstrate the applications of TRITON to generate flood inundation maps in multiple cases studies. Specifically, we focus on large scale (>400 million grid cells at 10m spatial resolution) flood events associated with the Tropical Storm Imelda and Hurricane Laura in Texas and Louisiana. Finally, we discuss the ongoing effort to expand TRITON’s capability to global scale and the associated challenges.

Applications of a High-Resolution, Multi-GPU Accelerated 2D Hydrodynamic Flood Model (TRITON) for Large-Scale Floodplain Modeling

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