ÖZKızılırmak Havzası, Fırat-Dicle Havzası'ndan sonra Türkiye'nin en büyük havzasıdır ve Türkiye'nin en uzun nehrine (Kızılırmak Nehri) METEOROLOGICAL DROUGHT ANALYSIS IN KIZILIRMAK BASIN USING STANDARDIZED PRECIPITATION INDEX METHOD ABSTRACTKızılırmak Basin is the largest basin in Turkey after Fırat-Dicle Basin and has the longest river of Turkey (Kızılırmak River). The basin is surrounded by West Karadeniz and Sakarya Basins in the west, Yeşilırmak Basin in the east, Konya Closed Basin in the southwest, and Seyhan and Fırat-Dicle Basins in the southeast. Drought analysis is important for the planning and management of water resources. In this study, droughts occurred in Kızılırmak Basin between the years 1973 and 2013 were investigated by using standardized precipitation index (SPI) method. SPI values of Kızılırmak Basin were calculated for 1, 3, 6, 9, 12 and 60-month time scales and 60-month time scale was used for the first time for drought analysis of Kızılırmak Basin based on SPI. When compared with the droughts in the past, important increases in the durations of the last droughts occurred in the basin were determined for 12 and 60-month time scales.