Edmund Tomaszewski

Abstract

The aim of this contribution has been to identify severe hydrological droughts in centralPoland, and to analyse the temporal and spatial patterns they display. The distinguishing of lowflowperiods was based on the threshold level method, where the SNQ (mean value of the minimumannual runoff) was used as the criterion. Basic calculations were made for daily dischargeseries at 29 gauging stations situated in the basins of the Rivers Warta, Pilica and Bzura over thetime period 1966–1983. Analysis involved such parameters as: mean and maximum low-flow durationin half-years, low-flow type index, date of commencement and termination and characteristicsconnected with minimum runoff: date of occurrence, index of position as well as recessiontime index. The problems of hydrological drought stability over a multi-annual timeframe, as wellas the spatial pattern thereto were also analysed.

Keywords: hydrological drought, low flows, central Poland

Edmund Tomaszewski, Faculty of Geographical Sciences, University of Łódź, 90-139 Łódź, ul. Narutowicza 88, Poland