Analysis of meteorological drought in Slovenia with two drought indices (original) (raw)

Meteorological drought is often described in terms of drought indices, which are simple to use and simultaneously absorb great amount of precipitation data, temperature data, ground water content data, etc. Two of them were used in analysis of meteorological drought in Slovenia: standardised precipitation index (SPI) and Palmer drought severity index (PDSI). SPI can be calculated on different time scales, which is better for determining drought onset, duration and intensity. SPI with its multiple time scale can be useful tool to determine the effects of precipitation shortages to ground water level, river discharges and soil water content. The comparison of two indices for location Ljubljana showed good agreement between the PDSI and SPI on nine-and twelve-month time scale. Both indices indicated that after 1900 Ljubljana experienced worst drought conditions in 1947. SPI on three-month time scale showed significant (α=0.05) negative trend for summer precipitation (period 1961-2006) for stations Ljubljana, Murska Sobota and Bilje, located in three different climatic regions within Slovenia. SPI on 6-months time scale for September 2003 indicated extreme precipitation deficiency in greater part of Slovenia, except northwest; where above average precipitation was measured. In 2003 Slovenia recorded its most severe drought conditions after 1950 in all agricultural parts.