Evaluation of some rapid flood forecast models: TOPMODEL MARINE

摘要

The characterization of flash flood is an opened subject. We can notice several characteristics. The precipitation responsible of their formation are violent and intense; catchments concerned are small or medium; the surface runoff is the main flood generator; and the infiltration plays a role in the losses evaluation of the rain measured. To simulate and to forecast such events, we use two deterministic, distributed and conceptual models : TOPMODEL and MARINE. MARINE is an operational and robust tool for flash flood forecasting already implemented in National Flood Forecast Service in order to be tested. It should supply pertinent data about the flood evolution for people responsible of forecast and should be applicable even for sparse historical and observed data with the integration of data from space imagery. The choice of the physical processes responsible of the rapid flood generation, adopted in these models, are very different. On the one hand the saturated contributive surfaces are modeled through the TOPMODEL concept; and on the other hand the rooting of the surface runoff is the factor determining of the flood genesis in the rainfall - runoff MARINE. To try to understand which is more appropriated than the other to simulate those particular floods, these two models are tested on two small French Mediterranean catchments for rapid floods that occurred recently. The calibration of these models is delicate, because the parameters have to keep physical meaning. Furthermore, we plan their use in real time forecasting.