OBSERVED VARIABILITY STANDARDIZED PRECIPITATION INDEX IN TURKEY

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. SPI is mainly from rainfall within the time period established by dividing the standard deviation of the mean of the difference is obtained. This technique is used an analysis of precipitation data. SPI, usually 1, 3, 6, 9 and 12-month precipitation totals by comparing the degree of moisture is based on statistical techniques. In this study, precipitation data is provided by the Turkish State Meteorological Service. SPI variability is investigated at 156 meteorological stations in Turkey. During the years of 1971, 1972, 1986, 2000 and 2003 have experienced moderate and severe extreme drought conditions. 1966, 1967, 1975, 1998 and 2010 years have experienced extreme and moderate wet conditions.