Analysis of meteorological drought with different indicators

Abstract

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 adjustable 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 in Ljubljana showed us good agreement between the PDSI and SPI on nine-month and twelve-month time scale. Both indices showed us that after 1900 Ljubljana experienced worst drought conditions in 1946. SPI on three months time scale showed us significant ( =0,05) negative trend for summer precipitation (period 1961 - 2006) for stations Ljubljana, Murska Sobota and Bilje (they are located in three different climatic regions within Slovenia). Six months SPI 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.