Evapotranspiration from a Green-Roof Storm-Water Control Measure

The ability to estimate the components of the hydrologic cycle is the key to the proper design and implementation of storm-water control measures (SCMs). Reuse, infiltration, and evapotranspiration (ET) are used by SCMs to reduce runoff. This study quantifies the ET component of a green-roof SCM water budget using weighing lysimeters for 3years demonstrating its significance. Each of the years (2009-2011) was different climatologically. The measured ET was compared with potential ET calculated by several methods. Further, the measured ET is analyzed for its dependency on climatological factors and previous rain day. The average daily ET was observed to range from 1 to 10mm/day depending on season, temperature, relative humidity, solar radiation, and antecedent moisture condition. (C) 2013 American Society of Civil Engineers.