LAUSR

Abstract. This article presents improvements and development of a post-processing module for the regional scale flood mapping tool, AutoRoute. The accuracy of this model to simulate low, medium, and high flow rate scenarios is demonstrated at seven test sites within the U.S. AutoRoute is one of the tools used to create high-resolution flood inundation maps at regional- to continental-scales. The model has previously only been tested using extreme flood events. In this article flood inundation results for low-flow events are shown to be accurate (average F value of 63.3 %) but tend to be overestimated, especially in flatter terrain. Higher-flow scenarios tend to be more accurately simulated (average F value of 77.5 %). Additionally, modifications to the AutoRoute model and post-processing scripts are shown to improve computational efficiency (i.e. simulation time) by over 40 % when compared to previous versions. With improved computational efficiency and the ability to accurately simulate both low and high flow scenarios the AutoRoute model may be well suited to provide first-order estimates of flooding within an operational, regional- to continental-scale hydrologic modelling framework.