Simulations of flows and water depth in a dendritic river system

This paper presents the development of a channel hydrodynamic model for simulating the behaviour of flows and water depths in a river network that may consist of any number of joined and branched rivers/streams, including both tidal and non‐tidal rivers. The model employs a numerical method—an integrated compartment method (ICM). The method greatly facilitates the set‐up of algebraic equations for the discrete field approximating the corresponding continuous field. Most of the possible boundary conditions that may be anticipated in real‐world problems are considered. These include junctions, prescribed flow, prescribed water depth (or cross‐sectional area), and rating curve boundaries. The use of ICM makes the implementation of these four types of boundary conditions relatively easy. The model is applied to two case studies: first to a single river and then to a network of five river branches in a watershed. Results indicate that the model can simulate the behaviour of the hydrodynamic variables that are required to compute chemical transport in a river‐stream network.