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ÖgeThe impact of climate change on future extreme precipitation in Turkey(Graduate School, 2021-08-06)This study investigates the impact of climate change on extreme precipitation in Turkey with the aid of both historical and model-based future projection data. Firstly, we have applied the equidistant quantile matching method and generated bias-adjusted extreme precipitation daily and sub-daily time series of 73 stations in Turkey from a 14 member CMIP6 ensemble. The resulting data are utilized for deriving the Intensity-Duration-Frequency curves for two future periods (2020-2050 and 2070-2100) and results are spatially presented. Thus, annual extreme precipitation with 1-hr, 2-hr, 6-hr, 12-hr, and 24-hr durations over Turkey are examined for 10-yr, 25-yr, 50-yr, and 100-yr return periods in two future periods through a CMIP6 ensemble-based analysis. The impacts of climate change on annual extreme precipitation in the regions of Turkey are estimated. Our CMIP6-ensemble analyses reveal that for the reference period 1970-2000 the highest impacts over Turkey are estimated for shorter duration (≤ 6-hr) generally higher-frequent annual extreme precipitation which may be attributed to the thermal enhancement due to the mean temperature increase in Turkey. Moreover, for all durations and frequencies covered here, till the mid-century, change in regional medians varies between 4.6-10.4% in the Marmara region, 4.9-8.4% in south-eastern Anatolia, 7.4-10.4% in the Aegean region, -1.8-0.8% in central Anatolia, 6.8-12.1% in eastern Anatolia, 5.2-7.2% in Black Sea region, 4-14.2% in Mediterranean region. Due to the high spatial variability of the extreme precipitation, both decreasing and increasing relative changes occur in the regions. However, by the end-century, the impact of annual extreme precipitation in the regions noticeably intensifies, relative regional medians raise to 18.5-21.7% in Marmara region, 14.8-18.7% in south-eastern Anatolia, 10.2-13.9% in Aegean region, 13.4-16.6% in central Anatolia, 19.3-23.3% in eastern Anatolia, 16.2-20.7% in Black Sea region, 15.1-21.1% in Mediterranean region. Coastal regimes in Turkey receive a higher amount of annual extreme precipitation than the continental parts, especially local extremes that are noticeable on the coastal line, which is projected for all future periods and extreme precipitation durations presented in this study. Moreover, according to the median of the relative changes among the regions, the south and north coasts of Turkey are subject to the impact of different annual extreme precipitation durations. Northern coastal regimes are projected to have the highest impact by the intensification of the short-duration annual extremes (≤ 2-hr annual extreme precipitation). Southern coastal regimes are estimated to have the highest impact by the longer duration (≥ 6-hr) annual extreme precipitation events. Central Anatolia, the only region with persistent decreasing median changes till the mid-century, experiences a substantial increase in the impact of the 1-hr and 2-hr high-frequent convective precipitation extremes at the end-century. Crucial for adaptation and mitigation strategies, our current practice of deriving and implementing Intensity-Duration-Frequency curves rely on the historical data, which may be insufficient for capturing the variable impacts of climate change. Consequently, underestimating the impact of climate change on extreme precipitation may result in a decrease in the capacity of the numerous hydrological systems to deliver the required services at their optimum. Thus, decision and policymakers should evaluate and consider the intensification of different extreme precipitation durations among both the regions and the future periods to eliminate the exacerbated vulnerability of the hydrological systems to climate change-related extreme precipitation events and manage adverse socio-economic consequences.