Mustafa Şahin DOĞAN
Climate change is expected to alter streamflow availability and timing. In the mid latitudes, including Turkey, with climate change more precipitation is expected as rainfall rather than snowfall. Furthermore, snowmelt runoff will shift to earlier months, reducing water availability in spring and summer, when it is most needed especially for irrigation water deliveries and hydropower generation. With increased winter precipitation and reduced spring runoff, streamflow availability is expected to increase, affecting reservoir operations. Therefore, adapting reservoir operations to changing climatic conditions is important. This study evaluates climate change effects on streamflow availability of the Kızılırmak River, the longest river within Turkey, and hydropower reservoir operations of the Yamula Dam, a large-scale reservoir located on the Kızılırmak with a storage capacity of 3476 million cubic meters and installed power capacity of 100 megawatts. 20 Coupled Model Intercomparison Project Phase5 (CMIP5) scenarios are evaluated, ranging from wetter to drier hydrologies compared to historical conditions. Hydroeconomic modeling approach is employed to represent reservoir operations, where the objective is to maximize daily total revenue, subject to lower bound, upper bound and mass balance constraints. Results show that peak historical storage moves to one month earlier, from June to May. Spring and summer reservoir storage mostly reduces, while winter storage increases under climate change. Reliable power capacity of 35.3 megawatts can be achieved even under the driest climate scenario. Hydropower revenue increases up to 40% under the wettest scenario, while it decreases up to 18% under driest scenarios, compared to historical climate. ORCID NO: 0000-0002-3378-9955

Anahtar Kelimeler: Climate Change, Hydropower, Reservoir Operations, Streamflow