Evaluation of the HEC-RAS 2D Model's Capability in Two-Dimensional Simulation of Tidal Flow Hydrodynamics (Case Study: Musa estuary)

Document Type : Research Paper

Authors

1 Water Research Institute, Tehran, Iran.

2 Department of Water Engineering, Faculty of agriculture, Ilam University, Ilam, Iran.

10.22059/jwim.2025.404101.1268

Abstract

The inherent complexity of tidal flows poses significant challenges for accurate analysis and prediction, necessitating the use of advanced analytical and numerical models. In this study, the capability of the two-dimensional hydraulic model HEC-RAS 2D was evaluated for simulating the hydrodynamics of tidal currents in the Musa Estuary, located in the northern Persian Gulf. The main objective was to assess the model’s accuracy in reproducing the temporal and spatial patterns of flow velocity and water surface elevation in a highly complex estuarine system. For the simulation, water level and flow velocity data were collected from four hydrodynamic stations over a 44-day period, covering two complete tidal cycles. The model geometry was generated by integrating local hydrographic survey data with the 30 m Copernicus digital elevation model, and further processed in a GIS environment with a horizontal resolution of 20 m. To enhance numerical stability and ensure better conformity of the mesh, the topological mesh-generation system of the latest HEC-RAS 2025 version was used. After calibration, the model demonstrated high accuracy in reproducing tidal behavior, with performance indices within an acceptable range (NSE = 0.94, RMSE = 0.079, MAE = 0.61). The depth and velocity distribution maps also showed good agreement with the actual dynamics of the system. Overall, the findings indicate that HEC-RAS 2D, particularly when using the advanced features of its latest release, can serve as a reliable and efficient tool for simulating hydrodynamic processes in tidal environments such as the Musa Estuary. However, some limitations were identified in simulating flow velocity near the estuary entrance, which may be due to the incomplete representation of external forcing effects.

Keywords

References

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Water and Irrigation Management
Volume 15, Issue 4
March 2026
Pages 861-878

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