One Dimensional Hydrodynamic Modeling of River Flow Using DEM Extracted River Cross-sections

Abstract

River cross-sections are the prime input to any river hydraulic model for simulation of water level and discharge. Field measurements of river cross-sections are labour intensive and expensive activities. Availability of measured river crosssections is scanty in most of the developing countries, thereby making it difficult to simulate the water level and discharge using hydraulic models. A methodology for extracting river cross-sections from Shuttle Radar Topographic Mission digital elevation model (SRTM DEM) of 3-arc second has been proposed in the reported study. The extracted river cross-sections were used to simulate the magnitude of flood in the deltaic reaches of Brahmani river basin located in the eastern India. Forty cross-sections along the reaches of the rivers were extracted from the DEM and were used in the MIKE 11 hydrodynamic (MIKE 11HD) model. Prior to using the DEMextracted river cross-sections in the model, the cross-sections were modified based on the results of the DEM error analysis. Four available measured river cross-sections were compared with the DEM-extracted modified cross-sections to examine their geometric and hydraulic similarity. By changing Manning's roughness coefficient (n), same stage-discharge relationship could be obtained in both types of crosssections. Subsequently, the DEM-extracted cross-sections were used in the MIKE 11HD model for the simulation of discharge and water levels at various sections of the rivers. The model was calibrated for the period of June 15-October 31 of the year 1999 and validated for the year 2003. The model validation results showed a close agreement between the simulated and observed stage hydrographs. The N. Pramanik et al. calibrated values of Manning's n were found to vary within the range of 0.02 to 0.033. The study revealed that freely available SRTM DEM-extracted river cross-sections could be used in hydraulic models to simulate stage and discharge hydrographs with considerable accuracy under the scarcity of measured cross-section data.

A hydro-sedimentary modeling system for flash flood propagation and hazard estimation under different agricultural practices

“…Manning's coefficient (n) was selected as a model calibration parameter (Pramanik, 2010) at different locations (riverbed and banks) along the downstream river reach. For the area of study, the calibrated Manning coefficient takes values equal to 0.035 in Riparian Zone 1, 0.04 in the Riparian Zone 2, and between 0.04 and 0.05 in Riparian Zone 3 (floodplains).…”

“…Commonly, these parameters are flood inundation, discharge and flow velocity (Patro et al, 2009;Pramanik et al, 2010). Hydrodynamic modeling can play a significant role in de-termining the values of these parameters.…”

Hydraulic routing of extreme floods in a large ungauged river and the estimation of associated uncertainties: a case study of the Damodar River, India

“…Encouraged by the success of previous studies such as Patro et al (2009a) and Pramanik et al (2010) in 15 routing flows with SRTM DEM-based cross-sections, we set up a similar 1D hydrodynamic simulation 16 using the HEC-RAS model. However, preliminary experiments gave unstable results at peak flow and it 17 was therefore decided that a simpler modelling framework would be used.…”

Consistent initial conditions for the Saint-Venant equations in river network modeling

“…Note that the need for consistency in an SVE model initialization is due to the coupling of nonlinearity and the water surface slope in the momentum equation, so common reduced-physics models (not 4960 C.-W. Yu et al: Initial conditions for Saint-Venant equations discussed herein) may not be as sensitive to consistent initial conditions. Saint-Venant equation modeling arguably dates from Preissmann's seminal work (Preissmann, 1961;Preissmann and Cunge, 1961), followed by decades of advances in techniques and applications (Cunge, 1974;Ponce et al, 1978;Cunge et al, 1980;Abbott et al, 1986;Zhao et al, 1996;Sanders, 2001;Pramanik et al, 2010). These models focused on hydraulics of short river reaches or main stem rivers that are easy to initialize for flow and depth.…”