Drought risk assessment in East Slovakia using SPI and RDI at different time scales

Drought monitoring has become a crucial issue around the world due to the increasing climate change. Numerous drought indices can be used for the analysis and predicting the interarrival time of different droughts. In the current study, spatial and temporal variability of droughts in East Slovakia are analyzed using RDI and SPI calculated in 3, 6, and 12 timescales reflecting various physical types of droughts. Drought analysis is done for data from seven meteorological stations for 50 years covering the period from 1972 to 2022. The 3 months SPI and RDI are used to detect the short-term/meteorological drought, 6 months SPI and RDI are used to detect the mid-term/agriculture drought but 12 months SPI or RDI are used to detect long-term/hydrological drought. ArcGIS Pro is used to represent the spacial distribution of all the results.The drought trends were analyzed using Mann- Kendall non-parametric statistical test. The occurrence of historical drought was also clasified according to their severity (moderate, severe and extreme drought). The results show a good relationship between short-term and mid-term SPI and RDI. However, the results of RDI-12 has a smaller time interface, ie drought identification is faster than with SPI-12 which indicate that RDI-12 is further sensitive than SPI-12. Generally, RDI gave better results than SPI highlighting the importance of considering evapotranspiration in drought assessments which is important when identifying long-term drought. Mann–Kendall test identified the significant negative trend in series of RDI 6, 12 time scales in Kamenica and Cirochou station. Implementing measures to minimize the negative effects of mid and long-term droughts on surface and groundwater levels, as well as on aquatic fauna and flora, is important for the area around the Kamenica and Cirochou station.