Fully Two-Dimensional, Overland Flood Simulations in Seconds

Abstract

A novel method of fully two-dimensional overland flood simulation has been developed based on the use of Lagrangian rivulets. The approach is 4 to 7 orders of magnitude more computationally efficient than the solution of the shallow water equations while nearly as accurate, meaning that simulations can be run in seconds or minutes on a laptop rather than hours or days on a high-performance computing architecture. This leap forward in flood simulation allows researchers and forecasters to include wider areas of coverage (country scale and greater), support resolutions down to 1-meter, and/or develop statistically relevant forecast ensembles. We will provide background on the method as well as highlight a number of use cases and results.