摘要
The Azzaba City located in the North East of Algeria has undergone rapid urbanization during the past few years. Infrastructure development has further enhanced the land use change process in the area. Bad land use management practices are thought to be the cause of increased flooding. While the characteristics of the precipitation are tied to the climatology of the region, and can change only over the long term, the urbanization, an antropic factor, changes more rapidly and plays a non negligible role in modifying the land use. It is thus very important to assess the runoff changes due to land-use changes. Moreover, the knowledge of the rainfall runoff relationship is an essential tool in modelling and design of urban drainage networks. In this paper two hydrological models, namely WBNM and HEC-HMS, and a GIS procedure are used to predict runoff hydrographs of a small urban catchment located in Azzaba city. The aim was to test the effect of catchment size and time steps on runoff hydrograph shape, and to evaluate the catchment reaction to a given rainfall event obtained from the established IDF Curves. Furthermore a sensitivity analysis of the parameters of the models is carried out. In addition the results of the models are compared with the observed runoff data, measured during a storm event that occurred in 11th of Mars, 2014. This calibration is performed by applying different situations of catchment size and time steps. Then, characteristics of calculated hydrographs were compared with the same characteristics of the same observed hydrographs and analyzed statistically. The results indicate that HEC-HMS provide acceptable simulations in the flood events, which WBNM fail to simulate. Finally, hydrographs simulated by the HEC-HMS model have the best fit with the real situation. It is necessary to generalize this study and build up the data base for the further application of rainfall runoff model in Algeria.