Assimilation of SAR data to operational hydrological runoff and snow melt forecasting model

Assimilation of ERS-2 SAR data to the operational hydrological runoff model using a nonlinear Bayesian techniques is demonstrated and tested. The developed assimilation technique combines SAR observations to runoff model by applying a constrained iteration procedure and forward modeling of SAR observations. The aim is to improve river discharge forecasts. The test site is located in the Northern Finland, in river Kemijoki drainage area. The satellite data consists of ERS-2 SAR images from four springs. The results show that inclusion of the satellite data can improve the performance of the discharge forecasting model during the snow melt period.