Paper Title
Assessing Hydrological Responses to Droughts in The Hirfanli Dam Basin, Turkey

Abstract
Nowadays, water scarcity is becoming a significant and common problem and also water quality is deteriorating rapidly in almost all over the world. They cause many social and economic problems, especiallyfor underdeveloped and developing countries. For this reason, the management of water resources has become more important during the recent years. In this respect, connections between the lack of rainfall due to climate changeand the impact of droughts on hydrologic systems in different regions have been examined. Drought events caused by decreases in rainfall frequently take place almost all over Turkey, which is located in a semi-arid area. The time, duration and intensity of drought cannot be predicted, so that drought in any region can be analyzed by using probabilistic and statistical methods. The analysis of how the droughts can be caused by thelack of rain on the hydrologicsystems of different regions might help define the drought events without predetermined time, duration and intensity.The Standard Precipitation Index (SPI) method is widely utilized by researches in the drought analysis. This method is very easy to apply since the only meteorological variable needed for it is precipitation. Another important advantage of it is the fact that is very flexible on the assessments of the drought on different timescales. For this reason, we utilizedthe SPI method for hydrometeorologic drought analysis in the Hirfanlı Dam Basin which covers upstream drainage areas of the Kızılırmak River, one of the major water resources of the country and is subject to frequent drought events. The regionally averaged SPI time series at different time scales are used to determine the most appropriate time scale for monitoring hydrometeorologic drought on river flows and reservoir storages in the dam basin. In addition, this study will be made on the basis of the basin drought forecasting, risk analysis and management studies, it is expected to provide important information to reduce the effects of drought and for sustainable water resource management. Keywordsó Hydrometeorologic Drought, SPI, River Flow, Reservoir Storages, The Hirfanlı Dam Basin, Turkey.