Enhancing outdoor thermal comfort in a historic site in a hot dry climate (Case study: Naghsh-e-Jahan Square, Isfahan)

Urban heat islands (UHI) pose a significant threat to the well-being of people and public health because of the more frequent and intense occurrence of heat waves in urban areas. As a result, it is crucial to prioritize enhancing thermal comfort in outdoor spaces and minimizing the impact of extreme heat in urban areas. This study focuses on historically significant Naghsh-e-Jahan Square, a UNESCO World Heritage site in Isfahan, Iran, located in BWK climate zone. This study employs the ENVI-met tool to analyze six design scenarios involving various configurations of green and blue infrastructure. Elements from both the historical and contemporary states of the square, including shading and non-shading trees (Pine and Platanus trees), as well as water in two forms (stream and pond), were investigated over a typical summer day to evaluate climatic parameters (Ta, Rh, Tmrt, and PET). Results reveal a robust correlation between Tmrt and PET; Furthermore, enhancing the green canopy with wind-aligned water surfaces maximizes PET improvement. The optimal case exhibits a 7.96 ℃ and 3.04 ℃ reduction in Tmrt and PET, changing thermal sensation from "very hot" to "warm." This study provides better understanding of passive strategies for improving outdoor thermal comfort in the historic Naghsh-e-Jahan Square.