Résumé

Knowledge of variation of the water surface elevation in a river is very important for developing hydraulic models able to
predict fooding and food hazard mapping. The roughness and DEMs resolution are factors that can afect the fow characteristics in a river. Manning\'s roughness plays a signifcant role because it is not a constant parameter and varies depending on
the length of the river. DEM resolution is potentially the crucial element to give better food estimations. The objective of the
present study is to assess the combined efects of Manning roughness and DEMs resolution to predict water surface elevation
of the Moudjar River by using HEC-RAS 1D model. In this study, diferent results were obtained from various combinations
of DEM resolution, and Manning roughness coefcients by applying the unsteady HEC-RAS (Hydrologic Engineering Centers- River Analysis System) 1D model on the Moudjar River in Algeria, to predict and quantify the performance regarding
actual water surface elevation extent and the generated water surface limits. Data from February 02, 2019, to February 07,
2019, were used to determine predictive accuracy. The simulation results of the stage level of the river fow for diferent
combinations of Manning’s roughness coefcient and DEM’s resolution show the closer values between the observed and
simulated stage hydrograph, only in the case of the coarser DEM resolution (50 m) where the results are very distant and
unacceptable. Statistical parameters such as Root Mean Square Error (RMSE), Mean Absolute Error (MAE), and Nash Sutclif
(NSE) were used to verify the model\'s accuracy and predictive ability. The results obtained and the methodology applied
to the Moudjar River can be used as a useful reference for HEC-RAS modelling and food predicting in Algerian rivers.

Information

Item Type:	Journal
Divisions:	» laboratoire de Modélisation et Analyse Socio-Economique en Science de l’Eau » Faculté des Sciences et de la Technologie
ePrint ID:	4238
Date Deposited:	2023-07-01
Further Information:	Google Scholar
URI:	https://www.univ-soukahras.dz/fr/publication/article/4238

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