DETERMINATION OF GRAIN SIZE FRACTIONS OF RECENT SEA SEDIMENTS IN THE SOUTHEASTERN BLACK SEA (TRABZON) COASTS


Yazır D. , Özşeker K. , Dinçer A. C. , Alkan A. , Yıldız İ.

INTERNATIONAL CIVIL ENGINEERING AND ARCHITECTURE CONFERENCE 2019, Trabzon, Türkiye, 17 - 20 Nisan 2019, ss.767-774

  • Basıldığı Şehir: Trabzon
  • Basıldığı Ülke: Türkiye
  • Sayfa Sayıları: ss.767-774

Özet

The Black Sea ecosystem is rapidly changing due to anthropogenic activities and climate change. It is seen that

the pressures on coastal ecosystems are increasing day by day with excessive nutrient release, chemical

pollution, changing of river regimes, dams and land reclamation. In addition, the use and improvement of stream

bed on the land and the presence of anthropogenic sets and settlements on the coast significantly affect the

distribution of water and sediments offshore. Especially unconscious coastal uses reduce the size of the beach

and make it difficult to use in the protection against natural geological processes. This study was carried out

seasonally in 2018 in order to investigate geological and anthropogenic interactions. In this context, the study

area has been determined as 3 stations located in the Trabzon port and Degirmendere effects area, and 2 stations

in Konaklar location which are represented of the Black Sea ecosystem. Sediment samples were taken from the

uppermost part of the sediment layer (0-5 cm) reflecting the current conditions. When the material distribution

within the sediment layer is examined as a percentage, 1% is gravel, 1% is fine gravel, 3% is very coarse sand, 6-

7% is coarse sand, 14-16% is medium sand, 24-25% is fine sand, 19-20% very fine sand and 28-31% clay of the

material. The d10, d30 and d60 effective values of sediment grain size distribution analysis curves were

calculated on average in each season. According to these calculations, the cu which is coefficient of uniformity

and the cg which is coefficient of grading were calculated as (cu=2, cg=0.66) in winter, (cu=3.17, cg=0.91) in

spring and (cu=2.71, cg=1) in summer seasons. According to these results, sediment material content was

founded uniform and not well-graded in winter and spring. But, it was founded non uniform and well-graded

material content in summer. The most important factor on sediment transport in marine environments, the

current speed is determined as 14- 38 cm/s and between 10-90 ° west to west. When the sediment pore volume is

examined according to the stations, it has been shown that the pore volume varies between 34.5-52%.