Assessing vegetation distribution based on geometrical and morphological characteristics of the urban fabric to provide thermal comfort for pedestrians: A case study in Sanandaj

Abstract

In previous studies, geometrical aspects of the buildings have been mainly considered in designing of the models, while the impacts of vegetation distribution have not been taken into account. The influence of building geometry on vegetation distribution to create a comfortable thermal environment for pedestrians has not received much attention. An examination of Sanandaj, a city in western Iran, in three fabrics, closed, linear, and open, has been conducted in this study. By using ENVI-met simulator, we studied the orientations, height-to-distance ratio of the buildings, and the geometric shapes of vegetation distributions. There have been two phases to the current research. The first phase includes evaluating the factors that may affect the modeling results in addition to validating ENVI-met software in selected fabrics. A comparison is also made of three model fabrics with and without vegetation in the first phase. The most important environmental factors in this research are air temperature, radiant temperature, wind speed, and physiological equivalent temperature (PET). The results show that there is a positive correlation between orientation and the level of comfort. In a closed fabric, the model with an east-west direction, height ratio of 0.12 and wholly vegetation distribution showed 15.31 % improvement in comfort level compared to the original fabric. The linear fabric with an east-west direction, height ratio of 0.42 and a central vegetation distribution indicated a 22.53 % improvement in the comfort level and in the open fabric, the model with height ratio of 0.75 and the central vegetation distribution improved comfort by 10.42 %.