Assessment of meteorological and hydrological droughts in the eastern Slovakia using SPI and SSI indices
Annotatsiya
Abstract This study assesses two drought indices; the Standardized Precipitation Index (SPI) and the Standardized Stream flow Index (SSI) at 12-month time scale. The major drought variables including: duration, severity and intensity were estimated. The indices are calculated by a parametric approach, which means the probability distribution is estimated for each month separately. The distributions are selected based on the Akaike Information Criterion and the EasyFit software. The parameters estimation was made using the maximum likelihood method. The joint behavior of drought characteristics and their long-term evolution in year was analyzed by the concept of Copula in the eastern part of Slovakia. Finally, the likelihood of moderate drought risk through joint return periods was evaluated.