Essay on Environmental Benefits Of Green Roofs
1. Storm water Management
Green roofs reduce storm water volume and slow down water flow, thus helping to alleviate the pressure on storm water infrastructure systems.
Green roofs capture and retain huge amounts of water that otherwise would go down the storm drains, absorbing anywhere between 50 to 95 percent of the rain that falls on site. This water can be contained in building tanks after passing through the green roof layers which act as a filter and reuse it as cleaning water.
The intelligent use of best management practices includes green roofs that intercept and delay rainfall runoff and reduce the peak flow rate. These practices can result in significant environmental improvements, as well as long-term savings to building owners and municipalities.
The chart to the right from Bruce Ferguson 's Introduction to Storm water: Concept, Purpose, Design (1998), shows the amount of impervious cover that development and the new impervious pavements produce.
2. Heat Mitigation In natural landscapes, vegetative canopy biomass greatly lowers air temperatures. By contrast, the artificial and altered surfaces common in urban land-and roof scapes greatly raises them. Average city rooftops can easily reach 40°C in the summer.
In urban areas, tightly sealed surfaces such as asphalt and concrete in parking lots and on rooftops…