Streamflow Response to Seasonal Snowcover Extent Changes in Large Siberian Watersheds

This study uses remotely sensed long-term (1966-1999) weekly snowcover extent data to investigate snowmelt runoff response to seasonal snowcover change in the large Siberian watersheds (the Ob, Yenisei and Lena basins). It quantified the seasonal cycles and variations of snowcover extent and river streamflow, and identified a clear correspondence of river streamflow to seasonal snowcover extent change, i.e. an association of low streamflow with high snowcover extent during the cold season, and an increase in discharge associated with a decrease of snowcover extent during the melt periods. This study also examined and compared the weekly mean streamflow with the weekly basin snowcover extent for the study period. The results revealed a very strong linkage between the streamflow and snowcover extent change during the spring melt season over the large Siberian watersheds, and developed a statistically significant weekly runoff - snowcover relation. This relation suggests a practical procedure of using remotely sensed snowcover information for snowmelt runoff forecasting over the large northern watersheds. Analyses of extreme (high/low) streamflow cases (years) and the associated snowcover conditions indicate an association of high (low) flood peak with late (early) snowmelt in the Ob and Yenisei basins. Comparisons of snowmelt timing with peak flow show different associations between these two variables among the large Siberian rivers. These results demonstrate that the NOAA weekly snowcover extent data are useful for understanding and predicting streamflow changes in the arctic regions. Snowcover water equivalent data/products obtained by remote sensing technology and in-situ snow observations are currently being examined for what we expect will eventually improve hydrologic forecasts over the large northern watersheds.

http://climate.rutgers.edu/snowcover/