Seasonal Variations in Suspended Sediment Yield in the Baltic Sea Drainage Basin

The aim of this article is to describe the seasonal fluctuations of suspended sediment yield in the Baltic Sea drainage basin and to quantify the monthly inflow of suspended sediment to the Baltic. The seasonal fluctuations of sediment yield are controlled by rain and snow amounts and by ground thawing. The rhythm of the sediment yield shows great differences between mountainous and lowlandic areas, and also between areas with oceanic and continental climates. The seasonal fluctuations of the total suspended sediment inflow to the different sub-areas of the Baltic Sea imitate the seasonal regimes of the sediment yield within the different catchments. Most of the suspended load is supplied to the sea during snow melting. For the Baltic as a whole, the inflow reaches a maximum value in April (22.2% of the annual inflow) and a minimum value in January (3.7% of the annual inflow).