Green Roofs and the Urban Heat Island Effect
Green Roofs and the Urban Heat Island Effect Jason Jayanty Dr. Stuart Gaffin Dr. Cynthia Rosenzweig
What Are Green Roofs? § Green Roofs are roofs covered by vegetation § Two types of Green Roofs – Intensive – Heavy, expensive; capable of supporting large plants – Extensive – Light-weight patches of shrubbery § Green Roofs are advantageous for – Keeping buildings cooler in the summer and warmer in the winter – Protecting a city from combined sewage overflow during storms – Extend the life of a roof
Extensive Green Roof
Intensive Green Roof (photo by Don Carlson, Carlson Architects)
The Urban Heat Island Effect § The Urban Heat Island Effect refers to the fact that cities can be up to 5 -7º C hotter than the surrounding rural areas § This usually happens because… – – Anthropogenic heat (Man-Made) Concrete can absorb a lot of heat Tall buildings increase overall surface area for heat absorption Urban Canyon effect
Why New York City? § New York City has 5 times the area of Central Park in roof space (Gaffin et al, 2004) § If even half of these roofs were made green, It would have significant environmental effects. (Rosenzweig et al, 2005)
My Objective § My objective is to confirm LANDSAT surface temperature data at key sites of interest around New York City. § Measure differences between green roofs and black roofs § Measure how quickly surfaces heat up in New York
Observations for July 11, 2005 Observation Site Consistent with Photo Why 1 No Possible that the roofs that we couldn’t see hold a lot of heat 2 Yes A great deal of vegetation, high tree cover 3 No Unknown. Satellite may have been wrong. 4 Yes Amount of rocks may have counteracted the vegetation’s effects 5 No There was a row of trimmed trees here, and thus without vegetation, heat levels will rise 6 a Yes Vegetation has an obvious effect on the temperatures here 6 b Yes Some shade and vegetation, similar to 6 a, but on a lesser scale 7 Yes highly reflective surfaces and high heat-absorptions of surfaces make this area cool in the day.
Interesting Results So Far 113 th Street and Morningside Park
113 th And Morningside Data
Uris Hall Data
Further Research § Get surface and air measurements over the course of a day § Expand measurements of surface and air temperatures to other regions of high interest
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