Hydrological modelling of Wadi ressoul watershed, Algeria, by HEC-HMS model

Abstract

This study presents a flood estimation model for Wadi Ressoul in El Berda watershed, north east of Algeria. To ensure the overall consistency of simulated results, it is necessary to develop a validation process, particularly in regions where data are scarce or limited and unreliable. To this we must calibrate and validate the model over the hydrograph as measured at the output. Calibration and validation processes were carried out using different sets of data (CN, SCS Lag and Muskingum K). Evaluation on the performance of the developed flood model derived using HEC-HMS (hydrologic modelling system) yield a correlation coefficient R2 close to 1 and the Nash-Sutcliffe efficiency. We limit ourselves to modelling flood of short duration for which the process of evapotranspiration is negligible. Several events have been tested, including two to calibrate and one to validate the model. So it can be said that using the HEC-HMS model had the highest efficiency in with the values of these parameters calibrated, based on objective functions (percent error in peaks), with 8.8 percent difference between of observed and simulated discharges with R2 value is 0.87 and the Nash-Sutcliffe efficiency value is 0.99.