Paper Details

Storm rain water runoff is a major concern with urban areas. In urban areas the impervious surface likes rooftops,parking areas shopping areas and roads, paving, increase hazard of flooding due to storm water runoff. The reduction ofrainwater runoff is a most significant and ecological improvement of green roofs .The main components of green roofs likevegetations, substrates and drainage layer influence the water retaining capacity as well as storm rainwater runoff. In thevarious types of green roofs water holding capacity varies 40% to 60% of total rainfall. It can be up to100% depending onthe components of green roof system. Green roofs can retain all the small rainfall below 2 mm .Therefore it can reduce thehazard of flooding in urban area .Green roofs can improve the quality of storm water runoff comparative to theconventional roofs .It can absorb contaminants of heavy metals up to 90% of rainwater and filter the pollutants. Due toparticular attribute of storm water retaining ,it can reduce possibility of combined sewage overflow and expenditurecorrelated on its occasion. Green roofs can reduce magnitude of nitrate and phosphate of rainwater runoff. Green roof canreduce up to 54% of rainwater runoff of individual building .The rain water retaining ability of green roofs is lower inwinter than summer season. Green roof is an important tool to reduce rainwater runoff in urban area.

Arun Pal, Dr Rajesh Sharma, “The performance of green roof with storm rainwater runoff”, International Journal of Advance Engineering and Research Development (IJAERD), Vol. 4, Issue 10, pp. 632-639, October 2017.