Abstract
Evaporation from open water surfaces is often estimated based on the pan evaporation (Epan), which is anessential measure for estimating atmospheric evaporative demand. Within the Central European region, Epanappears to be slightly underestimated in the case of the hydrological balance of water bodies.
In the context ofthe recent multi-year period of drought, significant losses of surface water deposits were observed in countries ofCentral Europe. In spite of the'evaporation paradox'phenomenon, Epanis not generally decreasing as expectedby many studies from past decades.
Recorded observations from the Czech Republic show an increase in Epan,which is associated with an increase in global radiation and vapor pressure deficit. The vast majority of me-teorological stations show a strong or very strong increase in Epanduring April, June, July and August.
Duringthe 1971-2018 period, the annual mean Epanhas been increasing by an average of 2.97 mm yr-1. For the period2001-2018, the mean Epanwas 18% higher (519 mm) than the 1971-2000 average (440 mm).
Our simulationsof future scenarios, using regional climate models, predicted a growth in Epanof up to 27-54%. Such an increasein evaporation would cause serious consequences for surface water availability and agricultural productionduring the periods of drought in the Czech Republic, as the drought period 2014-2018 has clearly demonstrated.