design guidelines and maintenance manual for green roofs in the semi-arid and arid regions

This abstract includes the benefits associated with green roofs, how to select the type of green roof for a project, the important technical issues to address during design, implementation and maintenance of its longevity, detailed cost variables for green roof controlling quantity and quality of stormwater, cultivating the crop, and improving aesthetic environments in work and home settings in arid and semi arid regions. Much less rainfall goes into the soil and rest becomes stormwater runoff. These changes, in turn, increase erosion and degrade water quality. By promoting green infrastructure, it reduces, retains, and treats runoff at its source. This study investigates how roof substrate and vegetation affect rainwater retention. The investigated parameters are lightweight substrate ratio, substrate depth, precipitation and vegetation type. This study was done in Anantapur district, Andhra Pradesh, India. A planting box was placed on the roof of a building to simulate a green roof and the required conditions were mimicked. The experimental results indicate that precipitation, substrate depth, substrate ratio and vegetation type affect the rainwater retention capacity of green roofs. The rainwater retention rate is inversely proportional to precipitation intensity. According to the water retention capacity of various plants, black gram and schefflera arboricola have been chosen as they retain more water. Of the total amount of rainwater retained the substrate accounts for 77–98% and vegetation accounts for 2–23%. In the sub-tropical region, the green roof water retention rate is roughly 30% of the total storm precipitation (160 mm). Thus, using a green roof is an effective strategy for managing urban stormwater. This study also investigates calculating the average cost of green roofs and difficulties due to the number of variables. The final result a deeper green roof has been designed and high substrate is needed because black gram has been grown.