Publications internationales

2023
Said Kechida, Fares Laouacheria, Lotfi Zeghadnia. (2023), Assessment of the combined effects of Manning roughness and DEM resolution for the water surface elevation prediction using the HEC-RAS model: a case study of Moudjar River in the Northeast of Algeria. Modeling Earth Systems and Environment : Springer, https://link.springer.com/article/10.1007/s40808-023-01821-3

Résumé: Knowledge of variation of the water surface elevation in a river is very important for developing hydraulic models able to predict flooding and flood hazard mapping. The roughness and DEMs resolution are factors that can affect the flow characteristics in a river. Manning's roughness plays a significant 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 flood estimations. The objective of the present study is to assess the combined effects of Manning roughness and DEMs resolution to predict water surface elevation of the Moudjar River by using HEC-RAS 1D model. In this study, different results were obtained from various combinations of DEM resolution, and Manning roughness coefficients 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 flow for different combinations of Manning’s roughness coefficient 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 Sutcliff (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 flood predicting in Algerian rivers.

2019
F Laouacheria, S Kechida, M Chabi. (2019), Modelling the impact of design rainfall on the urban drainage system by Storm Water Management Model. Journal of Water and Land Development. : Journal of Water and Land Development 40 (1), 119-125, http://archive.sciendo.com/JWLD/jwld.2019.40.issue-1/jwld-2019-0013/jwld-2019-0013.pdf

Résumé: Flood modelling is an effective way to manage the stormwater network in cities. It aims to understand and predict the behaviour of stormwater network so that it can test and evaluate effective solutions to structural and operational problems. So simulation modelling stays a preoccupation for building a successful hydraulic modelling in urban areas. This study investigates the impact of the design rainfall on the hydraulic modelling results for the Azzaba stormwater network located in the North-East of Algeria by using the Storm Water Management Model (SWMM). Four scenarios of design rainfall events were compared for 10, 25 and 50-year return periods, where we used double triangle and composite curves for the design rainfall event definition. The results show the impact of the choice of design rainfall on the behaviour of the stormwater network, from which the results of simulation by the double triangle method for the short durations represents a great risk on the probability that the stromwater network can overflow and flood the city, with a difference in peak discharge estimated at 62.97% and 58.94% for 2 h and 3 h events compared to the peak discharge simulated by the composite rainfall method.