Evaluation of Drought Occurrence in Bilecik's Using Standardized Precipitation Index Method

Today, changes or anomalies in the climate, which is one of the biggest results to drought, has become a problem that affects all living things negatively. Since the time, duration and severity of the drought are not known in advance, probability and statistical methods are used when drought analysis is carried out. In this study, observed monthly total precipitation data obtained for 1980-2014 years from Meteorological Station in Bilecik were used. Standardized Precipitation Index (SPI) method for 1, 3, 6, 12, 24 monthly time scales were used and drought values were computed. As a result of the analysis, the drought was felt at maximum for 6 and 12 months periods and the most severe drought was observed in 1985 at 12 months period. When seasonally assessed, the drought usually occurs in the summer months, but it has also been observed in some periods during the winter months