“…The runoff of Turkish rivers is estimated at about 25 km 3 /year in which western part constitutes 9.93 km 3 /year and eastern part 14.9 km 3 /year, where the Kızılırmak brings 6.48 km 3 /year, the Sakarya -6.4 km 3 /year, the Çoruh -6.3 km 3 /year, the Yeşilırmak -5.8 km 3 /year (Simonov, Altman, 1991;Bulgakov, Yurkova, 2000;Jaoshvili, 2002;Goryachkin, Ivanov, 2006;Kostianoy, Kosarev, 2008;Kosarev et al, 2008;Mikhailov, Mikhailova, 2008;Grinevetskiy et al, 2015). According to different papers published in 1977-2019 the Black Sea freshwater runoff is estimated in the range between 338 km 3 /year (Simonov, Atman, 1991) and 517 km 3 /year (Margat, Treyer, 2004), while a mean value derived from these publications is of 401 km 3 /year (Poulos, 2019). Rivers play a key role in the state of coastal environment bringing water and sediments to the sea.…”