In this study, in order to estimate flow duration curves (FDC) for basins which have insufficient or unavailable flow data, a model which contains 39 streamflow gaging stations (SGS) in the Eastern Black Sea has been developed. 10 yearly discharge values and location data for each SGS, as well as, temperature, precipitation and location data for meteorological stations have been obtained and drainage areas have been determined. Annual temperature and precipitation values for each SGS were calculated by Thiessen Method. Logarithmic and exponential functions were applied to discharge values corresponding to 0 to 100, 20 to 100 and 30 to 100 percentage exceedance probabilities of each SGS and regression coefficients were obtained. The coefficients of exponential function have been correlated by topographic and climatic parameters of each SGS. Drainage area and density, total stream length and mean slope of tributariy values were topographic; and mean annual precipitation height and temperature values were climatic parameters. Discharge values with 10, 20, 30, 40, 50, 60, 70, 80 and 90 exceedance probabilities have also been correlated by topographic and climatic parameters of each SGS. As a result, the equations required to estimate discharge values at ungauged basins have been estimated by using two methods. It has been determined that the correlation coefficients are high and the relative errors are at acceptable levels and it has been concluded that these equations are reliable.
Key Words: Flow Duration Curves, Eastern Black Sea, Regression Analysis