The drought characteristics and their changes in selected water-gauging stations in Slovakia in the period 2001–2020 compared to the reference period 1961–2000

Abstract

Reassessing the hydrological characteristics with regard to drought is very important in the context of a changing climate. In this paper, we evaluate the drought in terms of changes in hydrological characteristics for the 20-year period 2001– 2020. The evaluation of changes is based on a comparison of data for this period with the currently valid reference period 1961–2000 in 13 selected water-gauging stations. In the analysis of the occurrence of subnormal mean annual discharges ( Q r <90% Q a,1961-2000 ), in most of the evaluated stations, the percentage incidence of such years is higher in the period 2001–2020 than in the reference period. The distribution of runoff throughout the year in the period 2001–2020 in comparison with the reference period in most stations confirms the changes identified in the previous evaluation of the period 2001–2015, i.e. the transfer of part of the usual increased spring runoff to previous, winter months. An exception was water-gauging stations on streams in the mountainous areas of northern Slovakia, where changes are reflected to a lesser extent.