Effects of Climate Change on Streamflow in the Ayazma River Basin in the Marmara Region of Turkey

This study investigates the effects of climate change on streamflow in Ayazma river basin located Marmara region Turkey using a hydrological model. Regional Climate Model (RCM) outputs from CNRM-CM5/RCA4, EC-EARTH/RACMO22E and NorESM1-M/HIRHAM5 with RCP4.5 RCP8.5 emission scenarios were utilized to drive HBV-Light (Hydrologiska Byråns Vattenbalansavdelning) A trend analysis was performed Mann–Kendall test for precipitation temperature projections. meteorological drought assessment presented Standardized Precipitation–Evapotranspiration Index (SPEI) method worst-case scenario (i.e., RCP8.5). The calibrated validated model used simulations period 2022–2100. selected models found produce high projections positive anomalies ranging 22 227 mm. increase annual mean temperatures reached up 1.8 °C 2.6 scenarios, respectively. results showed statistically insignificant upward downward trends significant at 5% significance level both RCP scenarios. It shown that there is intensities durations SPEI greater than 6 months after mid- century. Streamflow decreasing due and, hence, evapotranspiration. peaks obtained generally lower those scenario. values CNRM-CM5/RCA4 approximately 2 10% observation mean. On other hand, average value EC-EARTH/RACMO 22E significantly higher average, 32%. this can be useful evaluating impact developing sustainable adaptation options basin.