Droughts in the area of Poland in recent centuries
Rajmund Przybylak , Piotr Oliński , Marcin Koprowski , Janusz Filipiak , Aleksandra Pospieszyńska , Waldemar Chorążyczewski , Radosław Puchałka , Henryk P. Dąbrowski
AbstractThe history of drought occurrence in Poland in the last millennium is poorly known. To improve this knowledge we have conducted a comprehensive analysis using both proxy data (documentary and dendrochronological) and instrumental measurements of precipitation. The paper presents the main features of droughts in Poland in recent centuries, including their frequency of occurrence, coverage, duration and intensity. The reconstructions of droughts based on all the mentioned sources of data covered the period 996–2015. Examples of megadroughts were also chosen using documentary evidence, and some of them were described. Various documentary sources have been used to identify droughts in the area of Poland in period 1451–1800 and to estimate their intensity, spatial coverage and duration. Twenty-two local chronologies of trees (pine, oak, and fir) from Poland were taken into account for detecting negative pointer years (exceptionally narrow rings). The longest chronology covers the years 996–1986 and was constructed for eastern Pomerania. The delimitation of droughts based on instrumental data (eight long-term precipitation series) was conducted using two independent approaches (Standard Precipitation Index (SPI) calculated for 1-, 3-, and 24-month time scales, and new method proposed by authors). For delimitation of droughts (dry months), the criteria used were those proposed by McKee and modified for the climate conditions of Poland by Łabędzki. More than one hundred droughts were found in documentary sources in period 1451-1800, including 17 megadroughts. A greater-than-average number of droughts was observed in the second halves of the 17th century, and of the 18th century in particular. Dendrochronological data confirmed this general tendency in the mentioned period. The clearly greatest number of negative pointer years occurred in the 18th century and then in the period 1451–1500. In the period 996–2015, a total of 758 negative pointer years were recorded. Analysis of SPI (including its lowest values, i.e. droughts) showed that the long-term frequency of droughts in Poland has been stable in the last two or three centuries. Extreme and severe droughts were most frequent in the coastal part of Poland and in Silesia. Most droughts had a duration of two months (about 60–70%), or 3–4 months (10–20%). Frequencies of droughts with a duration of 5 and more months were lower than 10%. The longest droughts had a duration of 7–8 months. The frequency of droughts of all categories in Poland in the instrumental period 1722–2015 was greatest in winter, while in documentary evidence (1451-1800) droughts in this season are rarely mentioned. The occurrence of negative pointer years (a good proxy for droughts) was compared with droughts delimited based on documentary and instrumental data. A good correspondence was found between the timing of occurrence of droughts identified using all three kinds of data (sources).
|Journal series||Climate of the Past, ISSN 1814-9324, e-ISSN 1814-9332, (N/A 100 pkt)|
|Publication size in sheets||2.75|
|Keywords in Polish||susza, źródła historyczne, dendrochronologia, SPI, Polska|
|Keywords in English||drought, documentary sources, dendrochronology, SPI, Poland|
|ASJC Classification||; ;|
|License||Journal (articles only); author's original; ; before publication|
|Score||= 100.0, 28-03-2020, ArticleFromJournal|
|Publication indicators||: 2018 = 1.166; : 2018 = 3.470 (2) - 2018=4.009 (5)|
|Citation count*||1 (2020-05-18)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.