Integrated Modeling for the Determination of Typology and Boundaries of Coastal and Transitional

Eser, E.; Balas, L.; İnan, A., and Yıldırım Fidanoğlu, P., 2024. Integrated modeling for the determination of typology and boundaries of coastal and transitional. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 604-608. Charlotte (North Carolina), ISSN 0749-0208. The escalating pressures on the sustainable utilization of surface water resources have become more pronounced, driven by a confluence of factors, including rapid population growth, escalating consumption patterns, the impacts of global warming, climate changes, and fluctuations in water levels. Addressing these challenges necessitates the establishment of robust and effective water management systems. In alignment with the European Union Water Framework Directive (WFD), the development of comprehensive river basin management plans takes center stage to safeguard water resources and ensure their sustainable use. A pivotal stride in implementing this Directive within our country involves the meticulous determination of typologies and the digitization of transitional water bodies. This study focuses on the application of advanced modeling methodologies to delineate the geographical boundaries and types of coastal and transitional water bodies in Türkiye, guided by System B of the Water Framework Directive. Leveraging the three-dimensional hydrodynamic, transport, and water quality model, HYDROTAM-3D, developed for coastal areas with geographic information system and cloud computing support, alongside the Digital Elevation Model (DEM), our research explores the typologies and water bodies of coastal and transitional waters. Fethiye Bay is presented as a case study on the Mediterranean Sea coast of Türkiye. We identified seven rivers discharging into the Bay using data from the European Environment Agency's Waterbase-rivers. The modeling efforts delved into long-term estuarine hydrodynamics, analyzing coastal currents and water level changes attributed to wind, wave, tide, and density fluctuations. Through these studies, we determined the boundaries of fresh and coastal water within transitional water bodies. Notably, five out of the seven rivers exhibited characteristics indicative of transitional waters. Key factors such as latitude-longitude, surface area, and wave exposure were identified as crucial typology parameters. All identified transitional water bodies were classified as small surface area types, with the largest belonging to the Murt River at 6.96 ha. Wave exposure typology classes were established based on long-term wind and wave climate modeling, revealing the prevalence of the moderately sheltered type, constituting 42% of Fethiye Bay. This study underscores the significance of modeling studies as indispensable tools for effective water resource management.