@article{article_1658661, title={Sustainable Water Management in the İzmir Bay Sub-Basin: An Evaluation of Water Resources with the WEAP Model}, journal={Jeoloji Mühendisliği Dergisi}, volume={49}, pages={95–110}, year={2025}, DOI={10.24232/jmd.1658661}, author={Durmuş, Hazal and Elçi, Şebnem}, keywords={Climate change scenarios, Izmir Bay sub-basin, WEAP model, water resources management}, abstract={Water is essential for life. It plays a critical role in sustaining both natural ecosystems and urban environments. However, the sustainability of this vital resource is increasingly at risk due to growing pressures. The İzmir Bay sub-basin, located in the semiarid western region of Turkey, holds significant economic, ecological, and social importance. However, the region’s water resources are facing significant challenges due to rapid urbanization, population growth, and the impacts of climate change, with vulnerability expected to increase in the future. This study employs the Water Evaluation and Planning (WEAP) model to evaluate water potential, address domestic and agricultural water demands, and explore management strategies for sustainability of the region. The research first examines available water resources that supply water to eleven districts in the former metropolitan area of İzmir province (Balçova, Bayraklı, Bornova, Buca, Çiğli, Gaziemir, Güzelbahçe, Karabağlar, Konak, Karşıyaka, and Narlıdere) within the sub-basin. Population projections for the region up to 2050 were also estimated to understand water demand. Additionally, favorable and unfavorable scenarios were developed based on projected changes in temperature, precipitation, and flow rates under the RCP4.5 scenario. These projections utilized MPI-ESM-MR and HadGEM2-ES, both of which are state-of-the-art global climate models. Three scenarios —reference, optimistic, and pessimistic— representing varying climatic and hydrological conditions were analyzed using the WEAP model. Findings indicate a sharp rise in water demand, reaching 318.25 hm³ by 2050 in the reference scenario, while the pessimistic scenario forecasts the highest demand at 381.59 hm³. Unmet demand could rise dramatically under pessimistic conditions, reaching 160.9 hm³ by 2050. This emphasizes the urgent need for mitigation strategies. The optimistic scenario demonstrates that proactive policies and climate resilience measures can prevent shortages and provide water balance. Without strategic interventions, İzmir Bay’s water security will remain at risk. Forward-looking policies and effective management are essential to ensure equitable and sustainable water distribution in the face of growing demand and climate change pressures.}, number={3}, publisher={TMMOB Jeoloji Mühendisleri Odası}