AGU Fall Meeting , California, Amerika Birleşik Devletleri, 9 - 13 Aralık 2024, ss.1, (Özet Bildiri)
Increasing urbanization, changing habits, and emerging global warming are posing serious pressures on natural resources. Domestic and industrial water demands, land use changes, and flood irrigation are stressing water resources and causing environmental water requirements to be underestimated. The Water-Energy-Food (WEF) Nexus approach recognizes that all pillars are interconnected. While water scarcity causes food security problems, increasing food demand adversely impacts water availability. In addition, any negative change in the nexus directly or indirectly alters the ecosystem functions. Therefore, it is necessary to manage the Water-Food Nexus in a holistic approach while minimizing the gap between supply and demand in agriculture. The Porsuk Watershed (Türkiye) is a semi-arid region covering an area of 10,825 km2 and is highly dominated by urban, agricultural, and industrial sectors. Porsuk Stream is the most important tributary of Sakarya River with a length of 448 km. For the sustainable management of groundwater and surface water resources in the watershed, several methods are needed. One of these, the Circular Economy (CE), aims to reduce pressures on the WEFE nexus and the environmental impact of resource exploitation while seeking to enhance economic benefits. Circular economy models contribute to agricultural sector security by enhancing water allocation for irrigation. The aim of this study is to assess the performance of circular economy models to increase water security and reliability in the agriculture sector with the hydrological model of the Porsuk Watershed created between 2004-2021 using the Water Evaluation and Planning System (WEAP). Thus, contributions to the decision-making processes of stakeholders in the watershed can be provided according to scenario performances. With the Reduce scenario, the water demand across all sectors is decreased, leading to an increase in resource reliability. The unmet demands of agricultural areas that rely on groundwater were significantly mitigated through Reuse scenarios. Additionally, more irrigation can be carried out in agricultural areas that draw water from surface water sources due to increased flows in the Porsuk Stream. Reuse has also promoted reducing pressures on water resources while achieving sustainable agriculture.