Water Level Regime of Arctic Rivers according to Modeling and Satellite Measurements

Increasing accuracy of satellite altimetry water level retrievals, especially over rivers with seasonal ice cover, motivated the application of satellite observations for improving hydrodynamic models. Altimetric water level measurements are particularly valuable in areas with limited in situ data on river bed and floodplain topography as well as under conditions of insufficient data on water discharge and water level. The MIKE11 one-dimensional hydrodynamic model was adapted for the Lower Kolyma. The model was calibrated using the water level measurements at the Kolymskoe water gauge station located in the upper part of the reach. The verification of the simulated water levels against altimetry data was performed. The comparison of simulated and satellite-derived water levels at seven locations has shown that the model reproduces well the water level variability throughout the analyzed reach (167 km). The accuracy of the water level simulations as compared to the altimetric measurements varied from 0.20 to 2.75 m (or 13-62% of the seasonal amplitude).