Characteristics of dry and hot extreme events in Croatia

This study analyses the characteristics of compound dry and hot (DH) extreme events in Croatia. As in many parts of the world, such events have become more frequent in Croatia in recent decades. In this work, measured data collected at local meteorological stations were used. The analysis covers the period from 1963 to 2021. Croatia’s geographical location includes parts of the Pannonian Basin, the mountainous regions of the Dinarides and the coastal parts of the eastern Adriatic. Therefore, both continental and coastal stations are included in the analysis.    

In this study, the temporal and spatial characteristics of DH events are analysed. Precipitation and daily maximum temperature data were used to define DH extremes. The frequency and intensity of DH events in different time periods were analysed. As an additional measure of the dryness of atmospheric conditions, the characteristics of the water vapour pressure deficit during DH events were analysed. The results show an increase in DH events at all stations considered, with the increase being somewhat more pronounced at the continental stations. In addition, an assessment of the compound effect of drought and high temperatures was calculated using cumulative heat. This measure also shows that the characteristics of compound DH events are changing and becoming more intense.  

The impacts of compound extremes can have more severe consequences for humans and the environment than the occurrence of individual extremes alone. The change in the characteristics of extremes in terms of their intensification and increasing frequency can cause significant damage to agriculture, the energy sector, etc. Therefore, it is necessary to continue research on DH events to better understand the mechanisms of their occurrence and the atmospheric conditions that support them. With better preparation and adaptation, it may therefore be possible to improve the risk assessment of extreme events and reduce their harmful consequences.