Observed changes in extreme precipitation in Poland: 1991–2015 versus 1961–1990

Abstract

Several episodes of extreme precipitation excess and extreme precipitation deficit, with considerable economic and social impacts, have occurred in Europe and in Poland in the last decades. However, the changes of related indices exhibit complex variability. This paper analyses changes in indices related to observed abundance and deficit of precipitated water in Poland. Among studied indices are maximum seasonal 24-h precipitation for the winter half-year (Oct.-March) and the summer half-year (Apr.-Sept.), maximum 5-day precipitation, maximum monthly precipitation and number of days with intense or very intense precipitation (respectively, in excess of 10 mm or 20 mm per day). Also, the warm-seasonal maximum number of consecutive dry days (longest period with daily precipitation below 1 mm) was examined. Analysis of precipitation extremes showed that daily maximum precipitation for the summer half-year increased for many stations, and increases during the summer half-year are more numerous than those in the winter half-year. Also, analysis of 5-day and monthly precipitation sums show increases for many stations. Number of days with intense precipitation increases especially in the north-western part of Poland. The number of consecutive dry days is getting higher for many stations in the summer half-year. Comparison of these two periods: colder 1961-1990 and warmer 1991-2015, revealed that during last 25 years most of statistical indices, such as 25th and 75th percentiles, median, mean and maximum are higher. However, many changes discussed in this paper are weak and statistically insignificant. The findings reported in this paper challenge results based on earlier data that do not include 2007-2015.

Assessment of climate change and associated impact on selected sectors in Poland

“…Change detection in observation records of climatic variables in Poland was carried out for a range of variables of particular relevance and interest, such as temperature (Graczyk et al 2017), mean precipitation (Pińskwar et al 2018b;Szwed 2018), as well as intense precipitation (Pińskwar et al 2018a) and snow cover (Szwed et al 2017).…”

“…The most visible increases in the monthly precipitation totals as well as in the share of monthly precipitation within the annual total were found during the colder half-year, especially in March, with statistically significant trend detected for several stations in the northern and central parts of Poland. Pińskwar et al (2018a) noted the occurrence of many episodes of extreme precipitation excess and deficit in Europe and in Poland in recent decades that had caused considerable, and adverse, economic and social impacts. In Poland, the changes in values of climate indices were found to exhibit complex, spatial and temporal, variability.…”

Trend detection in river flow indices in Poland

“…Yet, there are regionally consistent seasonal changes and precipitation increase in spring and winter dominates. Pińskwar et al (2018b) showed that daily maximum precipitation for the summer half-year (Apr.-Sept.) increased for many stations and there were more positive changes during the summer halfyear than those in the winter half-year (Oct.-March). Szwed et al (2017) found that observed tendencies in time series of snow-related variables is complex and not easy to interpret.…”

“…in precipitation-based drought indices by Somorowska (2016). Pińskwar et al (2018a) analysed changes in observed daily precipitation records in Poland from 1951 to 2015. Trends were detected, but mostly weak and statistically insignificant.…”

Comparative Evaluation of the GPM IMERG Early, Late, and Final Hourly Precipitation Products Using the CMPA Data over Sichuan Basin of China

“…Precipitation plays a critical role in the global hydrological cycle and energy exchange of the atmosphere [1][2][3][4]. The uneven distribution of precipitation over large areas may directly cause the hydrologic system to be unstable [5][6][7] and easily lead to urban flooding, mountain mudslides, and flash floods [8][9][10].…”