watershed, reservoir, Turc Method, runoff, water yield
Abstract
In this research, directly measured flow values in three different basins in Thrace region, that is located in the Northwest Part of Turkey, were compared to the computed ones applying the Turc method to these basins. It is concluded that Turc method with original coefficients, 300 and 0.9, could not be used because of huge
discrepancies between the measured and calculated values. Instead, coefficients of 601 and 0.65, respectively, were used after the correction using long term measured flow rates. Employing the modified Turc method for these research basins, reservoirs volume are reduced by 50.7 %. This may decrease the total cost of the
reservoirs by about 20-30 % through reducing occupied surface area, embankment and crest height.
