Investigation of flood status by flood frequency analysis for the design of hydraulic structures in the Western Black Sea basin

In this study, Western Black Sea basin was selected. Flood flow rates of Samandere and Uğursuyu Deresi were calculated by different flood frequency analysis methods. Flood flow rates to be ontained from DSI and MGM measurement stations and method performances were compared. After the study, the frequency analysis method that best represents the region was determined. In this context, Flood Frequency Analysis(NTFA), Regional Flood Frequency Analysis(BTFA), Q2, Q5, Q10, Q25, Q50, Q100 and Q500 flood rates determined by DSI Synthetic Methods were compared with the measured floods. Thiessen polygon was formed. The optimum distribution of instantaneous maximum current values per year is to be selected from Normal Distribution, Log-Normal(Two-Parameter), Log-Normal(Three-Parameter), Person Type-3(Gamma Type-3), Log-Person Type-3 and Gumbel distribution types and Simirnov-Kolmogorov test results were evaluated. As a result of the calculations the flood flow calculated by the Regional Flood Frequency Analysis Method was determined as the project flood flow. It is concluded that the hydroelectric power plant project(HES) should be designed according to the flood flow rate determined by regional flood frequency analysis method.