Spatiotemporal characteristics of drought in Serbia

- The spatial variability of the drought was observed using S-mode PCA.
- SPI-12 and SPI-24 were used to determinate drought pattern.
- Three distinct sub-regions were identified by applying the cluster analysis.
- Six drought periods, which last about 30 years, were detected.
- The frequency distribution of the SPI-12 values was similar for each of the regions.

SummaryThe evaluation of spatiotemporal characteristics of drought was based on monthly precipitation data from 29 synoptic stations for the period of 1948-2012. The percent of normal precipitation was applied to illustrate the driest years in Serbia (1990, 2000, and 2011). The Standardized Precipitation Index (SPI) and S-mode principal component analysis (PCA) were used to capture the drought patterns. Agglomerative hierarchical cluster analysis was applied to identify three different drought sub-regions: (1) region R1 includes the north and the northeast part of Serbia; (2) region R2 includes the western part of Central Serbia and southwestern part of Serbia; and (3) region R3 includes central, east, south and southeast part of Serbia. The R2 had the monthly precipitation values above average, while R1 and R3 had the precipitation values under average of Serbia. The year 2000 was the driest and 1955 was the wettest during the observed period. The characteristics of drought were analyzed in terms of the temporal evolution of the SPI-12 values and the frequency of drought for the three identified regions. The percentage of years characterized by drought was 44.62% for R1, 50.77% for R2 and 46.15% for R3. Approximately 70% of the frequency of drought belongs to the near normal drought category.