Exploring the Spatial Distribution of Coastal Drainage Basins in Turkey

Abstract

Coastal regions are vital areas globally, serving as hubs for human habitation and economic activities. Water, being the fundamental resource for life, plays a crucial role in sustaining ecosystems and shaping coastal landscapes. The convergence of river systems in coastal zones underscores their significance in the hydrological cycle and aquatic biodiversity. However, managing these valuable yet vulnerable regions presents multifaceted challenges, necessitating robust management frameworks supported by monitoring and assessment tools. In Türkiye, a country with limited freshwater resources, the management of coastal zones is particularly complex due to increasing pressure on resources and land. This study examines the distribution and characteristics of river and coastal basins in Türkiye. Through spatial analyses on Geographical Information System and basin delineations with watershed modelling program, the study clarifies the regional differences and obstacles encountered by coastal provinces spanning the entirety of Türkiye's coastal borders. The results offer valuable understanding regarding the spatial dynamics of Türkiye's coastal areas with particular emphasis on the significance of Black Sea coastal basins and all coastal provinces. Firstly, river basin systems draining into the Black Sea constitute the majority of Türkiye's surface area. Although the Black Sea region covers only 14% of the total area, more than half of the country's surface area, excluding transboundary and endorheic basins, drains into the Black Sea. Similarly, the analysis of basin types reveals that coastal basins constitute approximately 18% of the drainage areas associated with our coastal waters, nearly one-fifth. This distinction between coastal basin and river basin boundaries differs from the traditional zoning approach in river basin management and coastal area management plans in Türkiye. Consequently, it is anticipated that this spatial evaluation, which has brought a new perspective, will significantly contribute to addressing management challenges, especially the studies that will be evaluated together with population and resource use.