Hydropolitics of Turkey and dams: The use of risk-based methods in design of reservoirs

Nowadays, available water requirement increases as a result of heavy population growth, industrialization and urbanization each passing day, inclusion of factors such as pollution, global warming, available water resources become don?t meet the demand. This case makes, producing water resources management policies and projects for prevention of water problem of countries, inevitable. In this context, in addition to many dams were built and are in built, also works to realize dam, hydroelectric plant and irrigation projects in our country especially The Southeastern Anatolia Project (GAP) region right away, are continued. Usually, flow regimes of rivers are not available for the demands. Structural differences between available water resources and demands make reservoirs necessary. Reservoirs are designed to meet energy production, irrigation, industry, river transportation, etc. on a river. The storage reguired depends on the magnitude and the variability of the river flows, the size of the demand, and the degree of reliability of this demand being met. In this study, the reason why the Kısıkdere (Değirmendere) sub-basin has been selected is that there is Yeşilkavak dam project planned by General Directorate of State Hydraulic Works (DSİ) and reservoir capacity-yield-reliability relationships are investigated for a single reservoir. By using monthly and annual mean flow data of DSİ-Değirmendere-Doğanlar streamgauging station on Kısıkdere (Değirmendere) in Gediz basin, the required reservoir capacity is estimated by using various critical period methods, behaviour analysis method, and deficit irrigation, and obtained results are compared with the planned reservoir capacity of Yeşilkavak dam. Additionally the probability of failure of planned reservoir capacity of Yeşilkavak dam is estimated by using Moran?s and Gould?s probability matrix methods.Keywords: Critical period, low flow hydrology, active reservoir capacity, reservoir capacity-yield-reliability relationships, probability matrix methods