Coastal management framework for Karasu

Karasu coastal zone has evolved for many thousands of years. The Sakarya River is one of the most important hydrodynamic factor as a source of sediment and flow in this zone. This coastal zone located at the West coast of the Black Sea and has 19 miles (30km) beach from The Sakarya River mouth to the West and 16 miles (25km) beach to the east. The coastal zone is quite important with The Acarlar deep spot. Since Karasu coastal zone should be considered as a whole ecosystem with aquatic, dune, deep spot and forest.The impact of hydrodynamic structure is very important to know for coastal engineering. Long-term wave datasets needed during the determination of coastaldefence structures planning, design, implementation, and shoreline changes. Today, numerical models are used for this purpose. In this study explores a range of uncertainty issues within the hydrodynamic structure and shoreline change in the Karasu coastal zone by using simulation with numerical model generated by Danish Hydraulic Institute (DHI).In the first step of the study, 2D Hydrodynamic MIKE 21 Model was used for a Black Sea basin simulation for a better understanding and creating new boundary conditions for hydrodynamic structure of Karasu coastal zone. Model results calibrated with thegeneral circulation of the Black Sea. In the second step, with the results of wave model 2D Coupled Mike 21 FM Model was simulated for Karasu coastal zone and calibrated with the results of the study Yüksel Y., and Saraçoğlu E., [22]. More detailed and small scale model for the Karasu region results include wave, current and sediment roses for the points which determined for different depths. For the assessment of the coastal morphology and shoreline change, 19 miles (30 km) beach from the Sakarya river xxiiimouth to the west was choosen as the study field. Numerical sediment transport model (LITDRIFT), numerical shoreline change model (LITLINE) and numerical cross-shore profile evolution model (LITPROF) was used for the simulation. Kamphius (1991) and CERC (1984) methods used for the calibration of LITLINE and LITDRIFT models. The results of the shoreline change model was verified with the digitized satellite images. The hydrodynamic wave model results also used as input parameters for the LITLINE LITDRIFT and LITPROF models.Meteorological data received from ECMWF (European Centre for Medium-Range Weather Forecast) and bathymetric data from SHODB, The Sakarya River's flow and sediment values from EİEİ were used both Hydrodynamic and Coupled Models. Field studies with the aim of determining sediment properties conducted in Yıldız Technical University Laboratory. Dune positions with heights were measured with Real Time Kinematic (RTK) GPS applications.As a result of this work coastal morphology, current and wave climate was found for Karasu coastal zone which is considered under risk zone. Also the global climate change and coastal defence structures appilcations effects are invastigate for the risk analysis. Key words: Hydrodynamic, MIKE 21 HD, Coupled Modelling, longshore sediment transport, shoreline change, LITLINE, LITDRIFT, LITPROF