A comprehensive study of floods in Poland in the 17th–18th centuries

Poland, with the regions of Baltic Coast and Pomerania, Masuria-Podlasie, Greater Poland, Masovia, Silesia, and Lesser Poland located in the basins of the Baltic Coast rivers, the Vistula River and the Oder River. This study focused on completing the documentation of historical floods in Poland before the 19th century and providing a valuable source for historical hydrology studies in Europe. To this end, a comprehensive database of all floods for the 17th–18th centuries was used, that was based on documentary evidence from 293 sources and 978 weather notes describing all flood occurrences. The finding of this study revealed the occurrences of 678 floods, including 37 new cases that have been discovered and documented only in this research. Spatial analysis of the results revealed that most of the floods occurred in the Vistula River basin. The number of floods by season was greatest for summer (JJA) (47 %) and smallest for autumn (7 %). Investigation of the origin of floods indicated that rain was the main factor contributing to occurrences of floods in Poland (38 %). The estimation of the intensity of floods showed that most of the floods were "smaller, regional floods" (257 cases) based on the Brázdil et al. (2006b) classification and "extraordinary" (501 cases) in the Barriendos & Coeur (2004) classification.