Clim. Past Discuss., https://doi.org/10.5194/cp-2018-135 Manuscript under review for journal Clim. Past Discussion started: 16 October 2018 c Author(s) 2018. CC BY 4.0 License. Extreme droughts and human responses to them: the Czech Lands in the pre-instrumental period Rudolf Brázdil1,2, Petr Dobrovolný1,2, Miroslav Trnka2,3, Ladislava Řezníčková1,2, Lukáš Dolák1,2, 5 Oldřich Kotyza4 1Institute of Geography, Masaryk University, Brno, Czech Republic 2Global Change Research Institute, Czech Academy of Sciences, Brno, Czech Republic 3Department of Agrosystems and Bioclimatology, Mendel University in Brno, Brno, Czech Republic 10 4Regional Museum, Litoměřice, Czech Republic Correspondence to: Rudolf Brázdil (
[email protected]) Abstract. The Czech Lands are particularly rich in documentary sources that help elucidate droughts in 15 the pre-instrumental period (12th–18th centuries), together with descriptions of human responses to them. Although droughts appear less frequently before AD 1501, the documentary evidence has enabled the creation of series of seasonal and summer half-year drought indices (SPI, SPEI and Z- index) for the Czech Lands for the 1501–2017 period. Based on calculation of return period for series of drought indices, extreme droughts were selected for inclusion herein if all three indices indicated a 20 return period of ≥20 years. For further analysis, only those from the pre-instrumental period (before AD 1804) were used. The extreme droughts selected are characterised by significantly lower values of drought indices, higher temperatures and lower precipitation totals compared to other years. The sea- level pressure patterns typically associated with extreme droughts include significantly higher pressure over Europe and significantly lower pressure over parts of the Atlantic Ocean.