Hydrological Regime of Ob' River System from Multi-Satellite Active/Passive Microwave Measurements
Kouraev, A1; Zakharova, E2; Mognard, N3; Cazenave, A3; Legresy, B3; Frederique, R3
1LEGOS/OMP, France and SOI, Russia; 2SOI; 3LEGOS/OMP
Among all the Arctic rivers Ob' is the largest one by the watershed area and the third largest by the runoff volume. We demonstrate application of satellite techniques for studies of hydrological regime of the Ob' river using a) altimetry data from TOPEX/Poseidon (1992-2002), Geosat Follow-On (since January 2000) and ENVISAT (since November 2002) satellites, b) passive microwave radiometry from SSM/I and c) satellite gravimetry observations from GRACE.
1). River level and discharge. Using relations between altimeter level data and in situ discharge measurements for the terminal observation station (Salekhard) we have estimated daily, monthly and annual Ob' river flow with very good accuracy, what provides a sound base for continuous monitoring of the Ob' discharge.
2). River ice cover. Satellite microwave data provide the mean to study temporal variations of dates of ice formation/break-up for Ob' itself and its main tributaries. Combination of data from satellite altimetry and passive microwave sensors gives an assessment of spatial and temporal variability of the dates of ice formation/break-up for the Ob'.
3). Flooded areas and bogs. Using satellite passive and active microwave data as well as GRACE observations, we analyse temporal variability of water content and extent of flooded areas and bogs in the Upper Ob' and Vasyugan region.