Abstract

Our aim is to present the grain size characteristics of surficial bottom deposits of the lowland dam reservoir. Two primary fractions: sandy and silty were distinguished. Nine types of deposits were determined based on the changes in contribution of these primary fractions in bottom deposits. The great instability and changeability of hydrodynamical conditions is a consequence of lithological variety of the deposits in the reservoir. It causes mixing of primary fractions. Lithodynamical analyses indicated the domination of redeposition, as a sedimentological process, combined with a short transport of sediments.

Keywords: bottom deposits, grain size composition, distribution of sediments, dam reservoir, Poland.