16th International Multidisciplinary Scientific Geoconference (SGEM 2016), Albena, Bulgaristan, 30 Haziran - 06 Temmuz 2016, ss.483-490
Drought is a natural hazard that is derived from defective precipitations. If precipitation is not sufficient during a longer period, scarcity of water and drought can be risk for living and human activities. Standardized Precipitation Index (Standardized Precipitation index (SPI)) commonly is used for the evaluation of drought frequency and severity.