SEDIMENT AND WATER DISCHARGE RATES OF TURKISH BLACK-SEA RIVERS BEFORE AND AFTER HYDROPOWER DAM CONSTRUCTION

Presently, the water discharge rate to the Black Sea by Turkish rivers is approximately 41 km3/yr. The, sediment discharge rate of Turkish rivers to the Black Sea is 28 x 10(6) t/yr. Before construction of the hydroelectric dams, the sediment discharge rate was approximately 70 x 10(6) t/yr. The sharp reduction in sediment load is largely a result of the dams near the mouths of the Yesil Irmak and Kizil Irmak rivers. Before the construction of dams, Turkish rivers contributed approximately one third of the total amount of sediment received by the Black Sea from all surrounding rivers. The life-span of the major reservoirs varies from approximately only one century (Yesil Irmak river reservoirs) to several thousand years (Sakarya river reservoirs). Life-span for the large Altinkaya Dam reservoir is estimated with approximately 500 yr.