Local flash floods in Central Europe: A case study of Poland

Abstract

Bryndal, T. 2015. Local flash floods in Central Europe: A case study of Poland. Norsk Geografisk Tidsskrift–Norwegian Journal of Geography. Vol. 69, 288–298. ISSN 0029-1951.The article focuses on the seasonality, geographical distribution, and hydrometeorological aspects of local flash floods in Poland, in Central Europe. Scientific articles describing local flash flood events were studied and a database of such floods in Poland was developed and analysed. The results revealed that local flash flood events were usually generated by rainfall lasting less than two hours, with a mean intensity in the range 20–80 mm·h-1. The triggering threshold for local flash floods was P = 20 mm·h-1. Local flash floods may occur from April to October, with higher frequencies in May, June, and July. The floods usually affect mountain and uplands areas differently to lowland and basins regions, and this might be explained by heavy rainfall distribution and topographical conditions. The maxima of the unit discharge (Qs) describe an envelope curve according to the equation Qs = 47A-0.4 (where A is the catchment area in km2). The maxima appear very consistent with envelope curves proposed for other inland continental European countries. The authors conclude that local flash floods in Poland are similar to those recorded in inland continental areas of Europe, but differ from the floods in the Mediterranean part of the continent.