Flow routing

Flow routing is a procedure to determine the time and magnitude of flow (i.e., the flow hydrograph) at a point on a watercourse from known or assumed hydrographs at one or more points upstream. The procedure is specifically known as Flood routing, if the flow is a Flood. In order to determine the change in shape of a hydrograph of a flooding as it travels through a natural river or artificial channel, different flood simulation techniques can be used. Traditionally, the hydraulic (e.g. dynamic and diffusion wave models) and hydrologic (e.g. linear and nonlinear Muskingum models) routing procedures that are well known as distributed and lumped ways to hydraulic and hydrologic practitioners, respectively, can be utilized. The hydrologic models need to estimate hydrologic parameters using recorded data in both upstream and downstream sections of rivers and/or by applying robust optimization techniques to solve the one-dimensional conservation of mass and storage-continuity equation. On the other hand, hydraulic models require the gathering of a lot of data related to river geometry and morphology and consume a lot of computer resources in order to solve the Saint-Venant equations numerically. However, nowadays, semi-distributed models such as Muskingum–Cunge family procedures are also available. Simple physically concepts and common river characteristic consist of channel geometry, reach length, roughness coefficient, and slop are used to estimate the model parameters without complex and expensive numerical solutions. In general, based on the available field data and goals of a project, one of these approaches is utilized for the simulation of flooding in rivers and channels.