Numerical modeling of water circulation and sediment transport for pollution control in Fethiye Bay: a compound analysis

2024-9-03
Karakütük, Bilge
This study focuses on the changing water circulation and sediment transport patterns in Fethiye Bay, a semi-enclosed basin located in southwestern Türkiye under the dredging activities considered for pollution control. The bay suffers from heavy pollution and sedimentation as a consequence of low circulation, inadequate waste management and waste discharge. Through the study, the water circulation driven by oceanographic (winds, tides and waves) and fluvial (river discharges) sources is assessed and the optimum dredging scenarios (area and depth) are identified by evaluating current patterns and sediment deposition within the bay. Bathymetric variations (erosion and deposition zones) over a fifteen-year period are analyzed and shallowing zones are identified. Then, a numerical modeling approach is taken by using Delft3D, incorporating the tide, wind, wave and river characteristics of the region. Available bathymetric, hydrographic, meteorological, and sea level data are utilized to set the model, and current velocity measurements are used for model calibration. The study results provide insights for dredging operations by evaluating different scenarios based on changes in water circulation and sediment transport. It finds a relation between the amount of water entering and leaving the bay and sediment deposition rates, primarily influenced by site characteristics, and evaluates the effects of dredging operations on water circulation and sediment transport with a multi-dimensional analysis, considering different dredging depths and wind directions. Recommendations are presented to serve as a roadmap for the planning of costly dredging operations.
Citation Formats
B. Karakütük, “Numerical modeling of water circulation and sediment transport for pollution control in Fethiye Bay: a compound analysis,” M.S. - Master of Science, Middle East Technical University, 2024.