Analysing the impact of climate change on evapotranspiration in a climate-sensitive region: Example of Central Anatolia (Türkiye)

Evapotranspiration (ET) is one of the main components of the hydrological cycle and plays a crucial role for water resources. It is sensitive to climate change, and therefore, estimating ET under changing climatic conditions is essential in comprehending hydrological processes, particularly in agricultural water management. In this study, the impact of climate change on ET in the Central Anatolia region of Türkiye was assessed. For this purpose, RCP4.5 and RCP8.5 climate change scenarios based on two Earth System Models, HadGEM2-ES and MPI-ESM-MR, were employed for three future time periods: 2025-2049, 2050-2074, and 2075-2098. As a baseline period for comparison, the time interval spanning 1980-2000 was considered. ET values were computed by using the Penman-Monteith equation, recommended by the Food and Agriculture Organization, along with five widely utilized methods. The study revealed a consistent increase in ET depending on the employed methods for the future period in response to climate change. The average of the ET amounts for the region was determined as 1089 mm for the reference period 1980-2000. As the average of the six methods utilized, amounts estimated by HadGEM RCP4.5, HadGEM RCP8.5, MPI RCP4.5, and MPI RCP8.5 models for the future period were obtained as 1 199, 1 285, 1 166, and 1 248 mm, respectively. Considering the results, it is found that the ET amount in the Central Anatolia region of Türkiye will increase by up to 11% by the end of this century under the optimistic RCP 4.5 scenario and by up to 19% under the extreme RCP 8.5 scenario. These findings regarding increased evapotranspiration play a significant role in water resource management and agricultural production planning in the region, holding crucial implications for sustainable agriculture.