The Ła¸czany Weir as a geochemical barrier in the migration of heavy metals

Investigations into the effect of damming the River Vistula on the distribution of heavy metals (Fe, Mn, Zn, Pb, Cu and Cd) in bottom sediments are presented. The main factors and processes decisive for the intense accumulation of heavy metals in the damming zone are discussed. The role of flow velocity as the basic factor in formation of a geochemical barrier limiting the intensity of migration of these metals in the river is stressed.