Modelling Culverts in Basilisk

Abstract

Flash-flood modelling is of utmost importance in order to forecast the extent of a potential heavy rainfall event. With the development of new flood forecasting tools, we are getting closer to real-time flood modelling goals. In small highly urbanized catchments and under extreme hydrological events, culverts may not be able to convey the entire stream. They are therefore submerged, and flow converts from open-channel flow to pipe flow. In most flooding simulations, the topography is locally lowered to create an open channel that allows water to pass through the hydraulic structure. This limits the impact of bridges and culverts. In this work, we will use the open-source software Basilisk(freely available at http://www.basilisk.fr ). The shallow water equations are solved thanks to a well balanced finite volume scheme on an adaptive mesh. The main goal of this work is to implement culvert modelling in this software to achieve more realistic simulations on flash flood modelling. We will validate our culvert model implementation on experimental data, we will then use the real case of November 1990 Reno River’s flooding to assess the performance of our model.