Application of SAR snowcover mapping to hydrological modeling of snowmelt runoff in Southern Ontario

In this experiment WATFLOOD, a distributed hydrologic model, was set up for the 1991 spring snowmelt event on the Grand River watershed to investigate the possibility of using airborne nadir C-band Synthetic Aperture Radar (SAR) imagery to update the model by providing snow covered area (SCA) information. WATFLOOD parameters were first derived using only atmospheric and ground data, the model was then run again to derive parameters using the SAR imagery to update the model. The results showed that model appeared to simulate the river flow better when updated using the SAR imagery. It was concluded that the present WATFLOOD optimization, which deals solely with river flows, allows for unrealistic values for snowmelt. This can be corrected by separate optimization of snowmelt parameters to known snow cover characteristics and of snowpack hydraulic characteristics to streamflow.