CLIMATE CHANGES AND SOIL WATER REGIME.

The research objective was to determine the duration of dry season based on the frequency of precipitation occurrence both upon 25% (Fa=25%) and 50% (Fa=50%) probability, respectively, for three major climate regions in Croatia (Mediterranean, moutainous and continental). In the Mediterranean region, soil water deficit was 246 mm upon 25% probability of precipitation occurrence. Upon 50% probability of precipitation occurrence, soil water deficit was lower, standing at 191 mm. In both cases, soil water deficit was determined during the summer months and it lasted for three months. In the mountainous region, there was a slight soil moisture deficit, which was 32 mm upon 25% probability of precipitation occurrence and 22 mm upon 50% probability of precipitation occurrence. Soil moisture deficit was determined in July or August. In the continental region, upon 25% probability of precipitation occurrence, soil moisture deficit was 230 mm and the dryness lasted for four months during the summer period, while upon 50% probability of precipitation occurrence, soil moisture deficit was 82 mm. Soil moisture deficit lasted for two months in the summer period (July and August). Higher soil water deficit with longer duration could be predicted in the future against the backdrop of the trend of increasing average annual air temperature in all the regions. [ABSTRACT FROM AUTHOR]