For four decades remote sensing has been a major source of information regarding the water storage and land cover conditions for large river basins. These data are also very valuable for the initialization, calibration, and on-line updating of hydrologic, hydraulic, and crop or vegetation growth models. These models are used for predicting and managing floods and droughts, irrigation scheduling, etc. This session welcomes novel approaches that focus on the merging of remote sensing data and model forecasts for operational purposes.