Green Roof Hydrologic and Water Quality Performance from Two Field Sites inNorth Carolina

摘要

Two green roofs were constructed and monitored in North Carolina’s NeusernRiver Basin (WCC in Goldsboro and B&J in Raleigh). Data was collected from WCCrnfrom April 2003 to September 2004; B&J data collection began in July 2004. Thernhydrologic and water quality performance of two different green roofs wererninvestigated. Each green roof retained a significant (p<0.05) proportion of thernrainfall, peak outflows were significantly (p<0.05) reduced from the green roofs, andrneach green roof had substantial delays in runoff. Both concentrations and amounts ofrntotal nitrogen and total phosphorus increased from rainfall to green roof outflow andrnfrom the control roof outflow to green roof outflow. It was determined that the soilrnmedia, composed of 15% compost, was leaching nitrogen and phosphorus into therngreen roof outflow. This field study demonstrated the importance of green roof mediarnselection in locations where nutrients are a concern.