Green Rooftop; Approach Towards Qualitative Improvement in Microclimatic and Tourism Attraction in Sustainable City

Today، thinkers and environment and urban designers are concerned about the inevitable growth of metropolises trying to propose some methods to moderate its effects. This has resulted in some patterns that reduce its disturbing effects along with improving the quality of life in these cities. Mankind is aware of the value of the sustained spaces and is trying to answer his needs، holding permanent horizons in view. These efforts resulted in patterns of sustained metropolises، a steady and dense city. But this human achievement is not، like his other achievements، without a consequence. Research shows that increase in the density of the city disturbs the balance in the illumination of the city spaces in addition to damaging the heat transfer between the earth، buildings and the atmosphere. It also affects the internal heat of the city، increases the temperature and influences the velocity of the wind. In another view. Higher density means a decreased opportunity for building green spaces resulting in a demolished desirability of the spaces. It also results in crowdedness and brings about air pollution. As flat planes that occupy a large share in such dense cities، roofs are of great importance to us. Good effects of green patterns on improving the climatic conditions like moderating undesirable consequences of dense cities decrease of heat and sun waves، the velocity of the wind and pollution posits a good potential in plans. Bruce''s non-hydrostatic model is used in this research to simulate a site in three conditions of its current state، increase in density and greening the roofs. Then effects of rooftop greening especially on air temperature and wind velocity are studied. Finally a comparison is made between the results of this research and other researches done in this field achieve a broader insight into how greening the roofs may affect low-scale environmental conditions specially in dense cities by using plants in higher scales. There is also a discussion about other benefits of this approach to show its value in architectural and urban projects.