A robust, numerically efficient model for unsteady flow routing in topologically complex river networks Conference

Leon, AS, Valverde, R, González-Castro, JA. (2012). A robust, numerically efficient model for unsteady flow routing in topologically complex river networks . 1119-1128. 10.1061/9780784412312.114

cited authors

  • Leon, AS; Valverde, R; González-Castro, JA

authors

abstract

  • We present a robust and numerically efficient model for unsteady flow routing through dendritic, looped and networks comprised of dendritic and looped sub-networks. The model builds upon the application of Hydraulic Performance Graph (HPG) to unsteady flow routing introduced by González-Castro and Yen (2000) and adopts the Volume Performance Graph (VPG) introduced by Hoy and Schmidt (2006). The HPG of a channel reach graphically summarizes the dynamic relation between the flow through and the stages at the ends of the reach under gradually varied flow (GVF) conditions, while the VPG summarizes the corresponding storage. Both, the HPG and VPG are unique to a channel reach with a given geometry and roughness, and can be computed decoupled from unsteady boundary conditions by solving the GVF equation for all feasible conditions in the reach. Using HPG's and VPG's results in a robust and numerically efficient model for flow routing because the performance graphs (PG's) provide pre-computed overall GVF solutions of the momentum and mass conservation equations and the computations for routing through the system mostly involve interpolation steps. Although, the HPG/VPG approach is a highly numerically efficient and robust approach, previous routing models based on this approach were formulated for single prismatic channels or channels in series, so they are not suitable for routing through dendritic and looped networks. Our model overcomes the limitations of previous HPG/VPG formulations, as it can be used for unsteady flow routing through any river network. In our model (OSU Unsteady Routing) we solve a system of nonlinear equations assembled based on information summarized in the systems' HPG's and VPG's, continuity and compatibility conditions of water stages at the union of reaches (nodes), and the system boundary conditions. We exemplify the applicability of OSU Unsteady Routing to a looped network and contrast its simulation results with those from the well-known unsteady HEC-RAS model. © 2012 ASCE.

publication date

  • September 17, 2012

Digital Object Identifier (DOI)

start page

  • 1119

end page

  • 1128