Suspended Sediment Yield in the Baltic Drainage Basin

The aim of this paper is to quantify the spatial distribution of suspended sediment yield in the Baltic Sea drainage basin, and to quantify the suspended sediment inflow to the Baltic. The sediment yield in the studied area varies in accordance with the potential erosion conditions in the morphological sub-units and reaches values from below 2 to almost 1,000 t/km2/yr. Topographical, pedological and climatic conditions are decisive for the sediment yield variations. The suspended sediment yield increases generally from north to south, and reaches maximum values in the lower parts of the Carpathians. In contrast, the Scandinavian mountains are characterized by low suspended sediment yield. The suspended sediment load derived from the source areas decreases during its transport to the Baltic as a result of sedimentation processes. In the largest rivers of the area no more than 20 to 30% of the sediment amount flowing from tributaries to the main rivers ends up in the Baltic Sea. The total mass of suspended material flowing to the Baltic Sea is 4,455,000 t/yr, 37% of which is carried into the Baltic proper. 20% of the total supply to the Baltic Sea comes from the Vistula river.