This study investigates the future wave climate-driven longshore sediment transport (LST) and shoreline change on the Karasu Coast, situated on the southwestern coast of the Black Sea, under the RCP4.5 and RCP8.5 wave climate scenarios. Within the scope of this study, hourly deep sea wave data between 2021 and 2100, according to the RCP4.5 and RCP8.5, were used in order to predict future LST processes. Net and gross LST rates were computed using various empirical and numerical methods based on hourly wave parameters. By the conclusion of the study period after 80 years, the average net LST rates were obtained as 48,000 and 51,500 m³/year in the RCP4.5 and RCP8.5, respectively, while the gross LST rates were 250,000 and 255,000 m³/year. Due to the increase in wave height and period in both climate scenarios compared to the historical data, the average gross LST rates are projected to rise in the future. The reduction in swell wave heights, coupled with an increase in wind wave heights, compared to the past has led to a reduction in net LST. The results show that, after 80 years, LST will have increased 2.5 times more in the near future in comparison with the middle future for both scenarios.

In this study, flow behavior in a meandering channel was investigated experimentally and numerically. The experiments were carried out for nine different cases on a channel consisting of 180° and 120° angle bends following successively. Measurements were conducted employing Acoustic Doppler Velocimetry (ADV) at 13 different points in the inner, middle, and outer bends of the sections located at significant bends along the channel. Depth-averaged velocity, velocity profiles, bed shear stress, and turbulence kinetic energy parameters were considered to understand the flow behavior in the meandering channel. A 1:1 scale numerical model of the experimental setup was generated using the Computational Fluid Dynamics (CFD) method through the verified FLOW-3D software (HYDRO 2022R1). It was found to be successful in estimating all parameters and was capable of investigating the flow behavior in the meandering channel. Additionally, a mesh independence study was performed, and four different turbulence models were compared. As a result, as the flow encountered the first meander in the channel, secondary flow occurred, and lateral momentum transfer took place. Therefore, velocity increased by approximately 30% from the first meander of 180° angles to the second meander of 120° angles. Therefore, the most critical zone was the inner bend of the 120-angle meander.

In the present work, the shoreline changes of a sandy beach in Karaburun, Turkey, are studied by using a numerical simulation model (LITPACK). The work is motivated by the considerable erosion and siltation problems caused a sediment deposition near and inside the harbor entrance which prevented the boat traffic and caused a vital problem for the harbor operations. The study's scope is two-fold: to help in understanding the dynamics of the beach based on results of the field work and to study the responses of this beach by numerical simulation, utilizing the topographic and sediment field data and measured wave data. The validation and verification of the numerical model was perfomed by RTK-GPS measurements. The results of the numerical simulation concerning the coastline evolution are found to be in agreement with the measurements.

Tsunamis can cause serious damage not only to coastal areas but also to riverine infrastructures and areas due to the long distance of waves ascending in rivers in the form of a bore. When a tsunami wave enters a river channel, it encounters a countercurrent, and the wavefront transforms into an undular or breaking bore. Some of the bores have the form of one initial wave with a train of smaller waves known as whelps (undular bore). In the others, such a wave train does not appear and only a step with a flat water surface behind can be observed (breaking bore) (Tsuji, 1991; Yasuda, 2010; Whuppukondur and Baldock, 2022). Field observations of tsunamis show that tsunami waves travel faster and further along coastal rivers than inland mainly due to low-elevation and water existence (in wet conditions), reduced obstructions, meanders, and converging boundaries. Tsunami propagation in coastal areas has been widely studied, but there is a limited number of studies investigating tsunami propagation into a river channel. The interaction between the propagating tsunami and countercurrent along the meandering stream and varying cross-sectional area and geometries along the stream is a complex problem. This research aims to investigate this problem by using physical modeling approaches along a meandering stream.