Past hydrological events reflected in Holocene history of Polish rivers

A database of 335 radiocarbon dates from Holocene fluvial sediments in Poland has been compiled. Each sample is characterized by 25 parameters. All samples were grouped into one of 7 regions characterized by hydrological regime, and one of 8 depositional environments. Statistical analysis was used to enhance the palaeoenvironmental data and 17 phases may be distinguished, 10 of which have a distinct sharp peak. Abandoned paleochannels (149 dates) clearly reflect the major wetter phases of the Holocene. An opposite picture is presented by overbank aggradation (86 dates) connected mainly with expansion of agriculture.Preliminary correlations are made on peat bog records, changes in vegetation, lake water level, rates calcareous tufa and speleothems growth, landslides phases and debris flow phases. These show many convergences, explained by climatic fluctuations during the Holocene.