Shallow Water Flow Simulation: From Mathematics to Reality

Nowadays, the great power of modern computers combined with well-designed numerical models allows to develop computational models able to deal with simulations of several coupled phenomena over detailed complex topography. An efficient and properly calibrated computational model represents a useful tool to provide insight into the catchment dynamics at hydrological and geomorphological levels. In addition, it allows to develop detailed risk management and conservation plans. The challenge of finding a compromise between computational time and level of accuracy and robustness has traditionally expanded the use of simplified models (2D) rather than full three-dimensional models for flood simulation. This work presents a GPU accelerated 2D shallow-water model for the simulation of flood events over non-erodible and erodible bed in real time. In particular, an explicit first-order finite volume scheme is detailed to control the numerical instabilities that are likely to appear when used in complex topography. The model is applied to reproduce real events in a reach of the Ebro River (Spain) and the Cinca River (Spain) in order to compare the simulation results with the field data in a large domain and long flood duration allowing an analysis of the performance and speed-up achieved by different GPU devices. The high values of fit between observed and simulated results as well as the computational times achieved are encouraging to propose the use of the model as forecasting system.