Pluvial conditions in Wroclaw, Poland

¹ Wroclaw University of Science and Technology, Faculty of Environmental Engineering, 27 Wybrzeże Wyspiańskiego Street, 50-377 Wroclaw, Poland
² Institute of Meteorology and Water Management – National Research Institute, 61 Podleśna Street, 01-673 Warsaw, Poland

^* Corresponding author : katarzyna.wartalska@pwr.edu.pl

Abstract

The paper presents rainfall conditions for the city of Wroclaw (Poland) in the multi-annual period 1960–2017. A decreasing tendency of annual precipitation totals on the level of –12.5 mm/decade and decreasing trend of the monthly total in November of –2.9 mm/decade has been shown. In remaining months, no statistically significant change trends were observed. The maximum daily rainfall amounts were recorded in summer months: 56.4 mm in June, 74.4 mm in July and 67.5 mm in August. The analysis of variability in the number of precipitation with daily amounts exceeding 10 mm showed statistically significant decreasing trends – a decrease in the number of days in the amount of 0.69 per decade (linear regression). In the case of rainfall exceeding 20 mm and 30 mm no statistically significant trends were noted – the number of days with such heavy precipitation is practically constant and amounts to an average of 3.84 and 1.44 precipitation per year.