Green Roof and Water Cycle Role in It

摘要

Water cycle, also called hydrologic cycle.Cycle that involves the continuous circulation of water in the Earth-atmosphere system.The most important processes involved in the water cycle are evaporation, transpiration, condensation, precipitation, and runoff.Although the total amount of water within the cycle remains essentially constant, its distribution among the various processes is continually changing.Because of land being full of concrete and asphalt, impervious surface, water flows off surfaces and reduces infiltration into ground water.Agricultural fields, suburban and urban lands are being replaced with non natural surfaces.Water cycle in areas like this is broken.Necessity of recovering green areas is becoming increasingly critical.Broken water cycle is one of the reasons.One of the potential remedy for this problem is green roof, worldwide agenda.Aim of this article is to picture green roof as a tool of improving urban water cycle.