The agricultural catchment of the Zagożdżonka river is situated in the Mazowiecka Lowland, one of Poland’s regions with the highest frequency of droughts. The records on discharge at the Plachty Stare gauging station on the Zagożdżonka river from the years 1963–2007 were investigated and the parameters of streamfl ow droughts were determined. To identify low-fl ow periods in daily discharge hydrograms, truncation levels SNQ (mean value of the minimum annual outfl ow) and Q90% (discharge determined from the fl ow duration curve) were used. The streamfl ow drought of 1964 was found to be the longest and most severe in the study period. The whole 45-year period had no winter droughts. In the recent years, streamfl ow droughts in the Zagożdżonka river have occurred with a frequency of almost one per year, but their extent and intensity have been smaller than those observed previously.

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