Use of the standardized precipitation index (SPI) and a modified SPI for shaping the drought probabilities over Turkey

Turkes M. , TATLI H.

INTERNATIONAL JOURNAL OF CLIMATOLOGY, cilt.29, sa.15, ss.2270-2282, 2009 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 29 Konu: 15
  • Basım Tarihi: 2009
  • Doi Numarası: 10.1002/joc.1862
  • Sayfa Sayıları: ss.2270-2282


This paper suggests a new methodology for the Standardized Precipitation Index (SPI), for studying different aspects of drought events in Turkey, including intensity, frequency and identifying the spatial and temporal patterns. The classical SPI is locally defined; for instance, for monthly scale or running means, a drought event would begin when the precipitation amount is below its long-term average. However, the proposed method considers the local-time means of the precipitation series by fitting an upper and a lower envelope to precipitation data to obtain the SPI values, thus it explicitly assesses a dry (or wet) spell of weather.