Evaluation of the Impact of Dam Reservoirs on Outdoor Thermal Comfort: The Case of Keban Dam Lake, Elazığ

Dams not only regulate river flow and provide essential irrigation for adjacent agricultural areas but also induce microclimatic modifications due to the formation of large water bodies. This study investigates the microclimatic effects of the Keban Dam, located in Elazığ, eastern Türkiye, with a particular focus on its influence on local thermal comfort conditions. Meteorological data spanning a total of 32 years were categorized into three periods: pre-construction (1963–1973), postconstruction (1974–1984), and a recent period (2011–2020). Thermal comfort was assessed using data from three meteorological stations, employing two widely recognized indices: The Temperature-Humidity Index (THI) and the Physiologically Equivalent Temperature (PET). The findings indicate notable changes in both climatic conditions and thermal comfort following the dam’s construction. Compared to the pre-dam period, an average increase of 1.0 °C in THI values was observed, with this rise evident in both summer and winter seasons. The 10-year PET analysis revealed average values of 13.8 °C at the Keban Meteorology Station, 11.1 °C at the Elazığ Airport Meteorology Station, and 12.0 °C at the Elazığ Regional Meteorology Station. These variations in thermal comfort are considered to result not only from the hydrological and surface energy balance changes associated with the dam’s reservoir, but also from broader climatic factors such as global warming. In this context, the findings contribute to a better understanding of anthropogenic landscape modifications and their long-term bioclimatic implications.