Seasonal fluctuations of water storage in the Ob River basin from satellite altimetry and SSM/I measurements
Frédéric Frappart(1) , Nelly Mognard(1) , Julien L'Hermitte(2) , Sylvain Biancamaria(1) , Benoît Legrésy(1) , and Anny Cazenave(1)
18 Av. Edouard Belin,
31401 Toulouse Cedex 9,
(2) CESBIO, 18 Av. Edouard Belin, 31401 Toulouse Cedex 9, France
Remote sensing offers new opportunities to monitor and better understand hydrological cycle of major river basins. Satellite radar altimetry is currently used to monitor the water level of large lakes, rivers, floodplains and wetlands, while satellite imagery (microwave and visible/infrared) can delineate flood extent over large river basins. Various studies demonstrate the possibility to combine observations from radar altimeters and satellite imagery to determine spatio-temporal variations of water volume over inundated areas located in large river basins. We apply a similar method to estimate surface water volume variations over the Ob river basin for twelve years of Topex/Poseidon, ERS-2 and ENVISAT altimeters and Special Sensor Microwave/Imager (SSM/I) data.
These results are then compared to discharge measurements of the Ob river, snow depth estimated by global hydrology models (LaD, WGHM, ORCHIDEE, GLDAS) and derived from SSM/I data.