Effects of Plants on the Parameters Involved in Thermal Comfort in Urban Space:A Case Study of Urban Green Wall in Tehran City

The relationship between man and nature and its importance in the urban environment is one of the issues considered by theorists and planners in the field of urban space for a long time. However, human beings as the basis for this relationship have  jeopardizing this vital interaction by making changes in cities for some time now. One of the significanr in human communication and the redidence in cities is his satisfaction by climate conditions. The outdoor thermal comfort is affected by the built environment, land cover, plant evapotranspiration, and other factors present at the site. In this study, among the ways of promoting thermal comfort in urban space, the use of plants is focused on. In this article, the effects of plants on temperature and relative humidity were firstly analyzed in a case study. Then, using Envi-met software, an existing urban block was simulated by placing hypothetical trees and another hypothetical block was simulated as well. According to the results, the air temperature in the places, which were very close to the nearly 50-cm plants, was obtained to be almost 0.5◦C lower than other places. In addition, the relative humidity within the studied limits was higher. Therefore, the effects of these two factors on improving the thermal comfort of urban microclimates, especially in hot seasons, could be well evidenced. The assessment of different types of plants also showed that the temperature adjustment could be achieved regardless of plant type.