نوع مقاله : پژوهشی
نویسندگان
1 پژوهشکده حفاظت خاک و آبخیزداری
2 پژوهشکده آبخیزداری
3 آزاد
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Two-dimensional hydraulic modeling is one of the most effective tools for analyzing flow behavior, assessing flood hazards, and designing water-abstraction structures in meandering rivers. In this study, the hydraulic behavior of the Atrak River in the Chat-Gonbad reach was simulated using the two-dimensional HEC-RAS model. The main objective was to evaluate the impacts of a proposed pumping station and its associated facilities on the spatial distribution of flow depth, flow velocity, water-surface elevation, Froude number, and stream power under maximum discharge conditions.
The input data included a high-resolution digital elevation model (DEM) with an approximate spatial accuracy of 0.5 m, daily and monthly hydrological records, flood-flow data, river geometry, roughness coefficients, and hydraulic boundary conditions. The results indicated that the maximum flow velocity under existing conditions ranged from 1.5 to 1.8 m s⁻¹, while the water-surface elevation varied between 63.66 and 64.85 m. Following project implementation, the flow-depth range increased from approximately 2.7–21.7 m to 3.9–24.9 m, and the water-surface elevation rose to between 65.92 and 67.18 m.
Furthermore, the distributions of flow velocity and stream power became more uniform, and energy concentration within river bends was reduced. Froude number values remained below unity throughout most of the study reach, indicating the dominance of subcritical flow conditions and overall hydrodynamic stability. The findings demonstrated that implementation of the proposed scheme enhances flow conveyance capacity, reduces the concentration of hydraulic stresses, improves morphological stability, and decreases the potential for local scour and erosion.
Therefore, the two-dimensional HEC-RAS model can serve as an effective tool for the design of pumping stations and regulating structures, as well as for flood management and water-resources planning in meandering rivers. The novelty of this study lies in the integrated assessment of the combined impacts of a water-abstraction system, a regulating structure, and a pumping station on the hydraulic characteristics of the Atrak River using a two-dimensional HEC-RAS model.
Two-dimensional hydraulic modeling is one of the most effective tools for analyzing flow behavior, assessing flood hazards, and designing water-abstraction structures in meandering rivers. In this study, the hydraulic behavior of the Atrak River in the Chat-Gonbad reach was simulated using the two-dimensional HEC-RAS model. The main objective was to evaluate the impacts of a proposed pumping station and its associated facilities on the spatial distribution of flow depth, flow velocity, water-surface elevation, Froude number, and stream power under maximum discharge conditions.
The input data included a high-resolution digital elevation model (DEM) with an approximate spatial accuracy of 0.5 m, daily and monthly hydrological records, flood-flow data, river geometry, roughness coefficients, and hydraulic boundary conditions. The results indicated that the maximum flow velocity under existing conditions ranged from 1.5 to 1.8 m s⁻¹, while the water-surface elevation varied between 63.66 and 64.85 m. Following project implementation, the flow-depth range increased from approximately 2.7–21.7 m to 3.9–24.9 m, and the water-surface elevation rose to between 65.92 and 67.18 m.
Furthermore, the distributions of flow velocity and stream power became more uniform, and energy concentration within river bends was reduced. Froude number values remained below unity throughout most of the study reach, indicating the dominance of subcritical flow conditions and overall hydrodynamic stability. The findings demonstrated that implementation of the proposed scheme enhances flow conveyance capacity, reduces the concentration of hydraulic stresses, improves morphological stability, and decreases the potential for local scour and erosion.
Therefore, the two-dimensional HEC-RAS model can serve as an effective tool for the design of pumping stations and regulating structures, as well as for flood management and water-resources planning in meandering rivers. The novelty of this study lies in the integrated assessment of the combined impacts of a water-abstraction system, a regulating structure, and a pumping station on the hydraulic characteristics of the Atrak River using a two-dimensional HEC-RAS model.
کلیدواژهها [English]
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