Modeling unsteady and steady 1-D hydrodynamics under different hydraulic conceptualizations: Model/software development and case studies

Abstract: The stage-discharge relationship is affected by hysteresis, especially in 1D river cross-sections with very mild slopes, and/or where backwater effects occur. To model these cases, hydraulic property (HP) estimations (e.g., hydraulic radius and conveyance) are usually required as closed-form functions of stage. However, these are typically unavailable for complex cross-sections with overbanks. For no sediment-laden flows, we created the HydroHP-1D tool to solve the 1D Saint Venant Equations aided by the cross-section HP stored in tables. It also simulates irregular and composite hydraulic cross-sections, allows hydrodynamic simulation using the single-channel method (SCM), and proposes the divided channel method (DCM) for steady and unsteady flow analysis. A wide range of applications in rivers such as the Little Washita River and the Upper Negro River, and comparisons with NOAA normal depth solver, HEC-RAS, and with an analytical solution shows a promising scenario of applying HydroHP-1D to estimate 1D steady and unsteady hydrodynamics.

Recommended citation: Gomes Jr, M.N., Rápalo, L.M., Oliveira, P.T., Giacomoni, M.H., do Lago, C.A. and Mendiondo, E.M., 2023. Modeling unsteady and steady 1D hydrodynamics under different hydraulic conceptualizations: Model/Software development and case studies. Environmental Modelling & Software, 167, p.105733.
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