Major Droughts in Slovakia in the Twenty-First Century

Abstract

It is supposed that because of the climate change, the extreme hydrological events are going to be more pronounced and more frequent in the future also on the territory of Slovakia. The occurrence, duration and severity of hydrological droughts in Slovakia were studied during 3 years of the twenty-first century – 2003, 2012 and 2015. Mainly the 2003 and 2015 belong to the warmest years of the twenty-first century with the occurrence of hydrological drought on the Pan-European scale. Data on average daily discharges at twelve discharge gauging stations across Slovakia were used. The data covered the period 1981–2016. Hydrological drought in discharges was evaluated using the sequent-peak algorithm (SPA) method; the fixed threshold value of the 80th percentile was applied. The threshold value was estimated for the reference period of 1981–2010. The theoretical Weibull and GEV frequency distributions were used for drought parameters calculation, their evaluation and comparison of the 2003, 2012 and 2015 droughts. Data calculated for the evaluated years were compared with the reference period of 1981–2010. Spatial distribution of hydrological drought occurrence was discussed in connection to meteorological drought occurrence analysis.