Greening the Rooftop; One step towards microclimatic amelioration and tourism attraction in Sustainable city

Subject Areas : Water and Environment

Marjan Khanzadeh Natanzi ¹ (.M.A of Urban Design, sciences and research branch, Islamic Azad University)

Received: 2008-10-21 Accepted : 2009-03-07 Published : 2009-03-21

Keywords: High density, Bruse Model, Simulation, Green Rooftops, Microclimatic,

Abstract :

AbstractToday, thinkers and environment and urbandesigners are concerned about the inevitablegrowth of metropolises trying to propose somemethods to moderate its effects. This has resultedin some patterns that reduce its disturbing effectsalong with improving the quality of life in thesecities.Mankind is aware of the value of the sustained spacesand is trying to answer his needs, holding permanenthorizons in view. These efforts resulted in patterns ofsustained metropolises, a steady and dense city.But this human achievement is not, like his otherachievements, without a consequence. Research showsthat increase in the density of the city disturbs thebalance in the illumination of the city spaces in additionto damaging the heat transfer between the earth, buildingsand the atmosphere. It also affects the internalheat of the city, increases the temperature andinfluences the velocity of the wind. In anotherview, higher density means a decreased opportunityfor building green spaces resulting in ademolished desirability of the spaces. It alsoresults in crowdedness and brings about airpollution.As flat planes that occupy a large share in such densecities, roofs are of great importance to us. Good effectsof green patterns on improving the climatic conditionslike moderating undesirable consequences of densecities decrease of heat and sun waves, the velocity ofthe wind and pollution posits a good potential in plans.Bruce’s non-hydrostatic model is used in this researchto simulate a site in three conditions of its current state,increase in density and greening the roofs. Theneffects of rooftop greening especially on air temperatureand wind velocity are studied. Finally a comparison ismade between the results of this research and otherresearches done in this field t achieve a broader insightinto how greening the roofs may affect low-scaleenvironmental conditions specially in dense citiesby using plants in higher scales. There is also adiscussion about other benefits of this approach toshow its value in architectural and urban projects.

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