Improvement in accuracy of large-scale flood model used by the U.S. Military

Follum, M. et al. (2020). “Improved Accuracy and Efficiency of Flood Inundation Mapping of Low-, Medium-, and High-Flow Events Using the AutoRoute Model”. Nat. Hazards Earth Syst. Sci.

This project presented improvements and the development of a postprocessing module for the regional-scale flood mapping tool, AutoRoute. The accuracy of this model to simulate low-, medium-, and high-flow-rate scenarios was demonstrated at seven test sites within the US. AutoRoute is one of the tools used to create high-resolution flood inundation maps at regional to continental scales, but it had previously only been tested using extreme flood events. Modifications to the AutoRoute model and postprocessing scripts improved accuracy (e.g., average F value increase of 17.5% for low-flow events) and computational efficiency (simulation time reduced by over 40 %) when compared to previous versions. Although flood inundation results for low-flow events are shown to be comparable with published values (average F value of 63.3 %), the model results tended to be overestimated, especially in flatter terrain. Higher-flow scenarios tended to be more accurately simulated (average F value of 77.5 %). With improved computational efficiency and the enhanced ability to simulate both low- and high-flow scenarios, the AutoRoute model is well-suited to provide first-order estimates of flooding within an operational, regional- to continental-scale hydrologic modeling framework.