标题：Challenges in flood modeling over data-scarce regions how to exploit globally available soil moisture products to estimate antecedent soil wetness conditions in Morocco
摘要：The Mediterranean region is characterized by intenserainfall events giving rise to devastating floods. In Maghreb countries suchas Morocco, there is a strong need for forecasting systems to reduce theimpacts of floods. The development of such a system in the case of ungaugedcatchments is complicated, but remote-sensing products could overcome thelack of in situ measurements. The soil moisture content can stronglymodulate the magnitude of flood events and consequently is a crucialparameter to take into account for flood modeling. In this study, differentsoil moisture products (European Space Agency Climate Change Initiative, ESA-CCI; Soil Moisture and Ocean Salinity, SMOS; Soil Moisture and Ocean Salinity by the Institut National de la Recherche Agronomique and Centre d'Etudes Spatiales de la Biosphère, SMOS-IC; Advanced Scatterometer, ASCAT; andERA5 reanalysis) are compared to in situ measurements and one continuoussoil-moisture-accounting (SMA) model for basins located in the High AtlasMountains, upstream of the city of Marrakech. The results show that theSMOS-IC satellite product and the ERA5 reanalysis are best correlated withobserved soil moisture and with the SMA model outputs. The different soilmoisture datasets were also compared to estimate the initial soil moisturecondition for an event-based hydrological model based on the SoilConservation Service curve number (SCS-CN). The ASCAT, SMOS-IC, and ERA5products performed equally well in validation to simulate floods,outperforming daily in situ soil moisture measurements that may not berepresentative of the whole catchment soil moisture conditions. The resultsalso indicated that the daily time step may not fully represent thesaturation state before a flood event due to the rapid decay of soilmoisture after rainfall in these semiarid environments. Indeed, at thehourly time step, ERA5 and in situ measurements were found to betterrepresent the initial soil moisture conditions of the SCS-CN model bycomparison with the daily time step. The results of this work could be usedto implement efficient flood modeling and forecasting systems in semiaridregions where soil moisture measurements are lacking.
