Analyse et comparaison des méthodes d'estimation des débits de crue dans les bassins versants non jaugés (cas du bassin versant cotier Algérois)

Abstract

Floods are one of the most dangerous natural phenomena in the world. The estimation of maximum flows in ungauged watersheds remains a major concern for the professionals of water development. In the Algerian context, the use of empirical formulas is the only solution used by engineers. Therefore, our work aims to explore the empirical formulas and existing methods for flows estimating in the gauged basins (CHIFFA and EL-HARRACH) of the large coastal Algerian basin. According to the results analysis, it is noted that for the CHIFFA watershed the Gradex method gives a flow rate closer to the observed flow with an error of 6.12% (T = 10 years), and for periods of High Returns period The Turraza formula gives low errors of about 2.54% and 1.8% (T = 50 years and T = 100 years), while the EL-HARRACH catchment, the Turraza formula is fine for estimating a higher flow. Near that observed rate of error 0.05% for return period of 10 years. For 50 years, 100 years and 1000 years return period, the Sokolovsky and Giandoti formulas give low errors of about 5.03% and 1.07%, respectively.