Hydraulic flood routing solves the one-dimensional Saint-Venant equations—the continuity and momentum equations for unsteady open-channel flow—to determine how flow depth and velocity evolve in space and time given an inflow hydrograph and a downstream boundary condition. Because these governing equations are nonlinear hyperbolic partial differential equations with no general closed-form solution, they are solved numerically by discretizing space and time into a finite-difference grid and marching forward from known to unknown time levels. This belongs to the branch of hydraulic engineering concerned with dynamic (as opposed to hydrologic) flood routing in open channels.
Hydraulic flood routing solves the one-dimensional Saint-Venant equations—the continuity and momentum equations for unsteady open-channel flow—to determine how flow depth and velocity evolve in space…