A parallel adaptive-resolution hydraulic flood inundation model for flood hazard mapping

There is a growing demand for improved high-resolution flood inundation modelling in large-scale watersheds for sustainable planning and management. In this work, a parallel adaptive-resolution hydraulic flood inundation model is proposed for large-scale unregulated rivers. This model utilised the public best available topographic data and streamflow statistics data from USGS. An adaptive triangular mesh is generated with fine resolution (similar to 30 m) around streams and coarse resolution (similar to 200 m) away from streams. The river flood-peak discharges are estimated using the regression equations from the National Streamflow Statistics (NSS) Program based on watershed and climatic characteristics. The hydraulic simulation is performed using a discontinuous Galerkin solver for the 2D shallow-water flow equations. The hydraulic model is run in parallel with the global domain partitioned using the stream link and stream length. The proposed model is used to predict the flooding in the Muskingum River Basin and the Kentucky River Basin. The simulated inundation maps are compared with FEMA maps and evaluated using three statistical indices. The results demonstrated that the model is capable of predicting flooding maps for large-scale unregulated rivers with acceptable accuracy.