Large scale hydrological model river storage and discharge correction using satellite altimetry-based discharge product

Charlotte Marie Emery, Adrien Paris, Sylvain Biancamaria, Aaron Boone, Stéphane Calmant, Pierre-André Garambois, Joecila Santos da Silva
2017 Hydrology and Earth System Sciences Discussions  
Land Surface Models (LSM) are widely used to study the continental part of the water cycle. Yet, even though their accuracy is increasing, inherent model uncertainties can not be avoided. In the meantime, remotely-sensed observations of the continental water cycle variables such as soil moisture, lakes and rivers elevations are more frequent and accurate. Therefore, those two different types of information can be combined, using data assimilation techniques to reduce model's uncertainties on
more » ... state variables or/and on its input parameters. The objective of this study is to present a data assimilation platform that assimilates into the LSM ISBA-CTRIP a river discharge product, derived from ENVISAT nadir altimeter water elevation measurements, over the whole Amazon basin. The study presents an initial development for a localization treatment that allows to limit the impact of observations to areas close to the observation and on the same hydrological network. This assimilation platform is based on the Ensemble Kalman Filter and can either correct the river water storage or the discharge: RMSE compared to gauge discharges are globally reduced until 21 % and at Óbidos, near the outlet, RMSE are reduced up to 52 % compared to ENVISAT discharge. Finally, it is shown that localization improve results along main tributaries.
doi:10.5194/hess-2017-516 fatcat:a7vqhkxasff6hnn7iwxqkpteqa