Application of the standardized precipitation index (SPI) to the Marmara region, Turkey

Since droughts are natural phenomena, their occurrences cannot be predicted with certainty and thus they must be treated as random variables. Once drought duration and magnitude are found objectively, it is then possible to plan for the transport of water in known quantities to the drought stricken areas either from other water resource alternatives or from water stored during wet periods. Drought period affects economic, social and political events and the summation of deficits over that period is referred to as the drought magnitude. Drought intensity is the ratio of drought magnitude to its duration. Drought properties at different truncation levels provide significant hydrological and hydrometeorological design quantities. In this paper, standard precipitation index (SPI) is used for determining drought properties of a given hydrological series. This index is applied to the Edirne, Istanbul, and Kirklareli rainfall records in Turkey and then the drought period, magnitude, and SPI values are presented in the form of tables.