Evapotranspiration from a Green-Roof Storm-Water Control Measure

Observation and Estimation of Evapotranspiration from an Irrigated Green Roof in a Rain-Scarce Environment

“…Yet, the observed ET rates during the summer with irrigation applied are not always significantly larger than the reported values in the rain-rich environments. The maximum monthly ET rates of the sedum and grass are lower than the maximum monthly average (7 mm d −1 ) reported by a multi-year study of sedums in Villanova, PA, USA with an annual rainfall of 817-1352 mm [42], but are close to the reported 4.94 mm d −1 in the rain-rich region [86]. There is no consistent relationship between the observed summer ET rates and the reported values.…”

“…The P-M equation serves as the keystone of other simplified equations like the Priestley-Taylor (P-T) equation [64] and the Advection-Aridity (A-A) equation [65], or revised forms, including the Food and Agriculture Organization (FAO) of the United Nations' irrigation and drainage method (FAO56) [48] and the American Society of Civil Engineers standardized reference ET scheme [66]. As the P-M equation and its descendants are commonly used for green roof ET estimation in the humid environment [32][33][34][35]42,43], the P-M equation and its two revisions are tested for the two vegetated covers. Non-vegetated cover, without the transpiration part (no crop coefficient and water stress coefficient), was excluded from the ET estimation.…”

“…Only representing the short, cool-season, well-watered reference grass, though, such values are presumed for green roofs as a routine [32,33,42,43]. As the cornerstone of all P-M derived methods, the original P-M equation was also examined to estimate ET a after calibrating the surface resistance parameter [69]:…”

Hydrologic processes that govern stormwater infrastructure behaviour

“…In some cases, the initial abstraction value was reported; this value was used to estimate I for green roofs and ET for control roofs, otherwise the I is assumed to be 0 because it is minimal over long timescales. Data compiled from Hutchinson, Abrams, Retzlaff, and Liptan (); Liu et al (); Moran, Hunt, and Smith (); Carter and Rasmussen (, ); VanWoert et al (); Villarreal and Bengtsson (); TRCA (); Mentens, Raes, and Hermy (); Berghage et al (, ); Teemusk and Mander (); Getter, Rowe, and Andresen (); Hathaway, Hunt, and Jennings (); Van Seters, Rocha, Smith, and MacMillan (); Berndtsson (); Fioretti, Palla, Lanza, and Principi (); Stovin (); Voyde et al (); Hoffman, Loosvelt, and Berghage (); Palla, Sansalone, Gnecco, and Lanza (); Carpenter and Kaluvakolanu (); Buccola and Spolek (); Gregoire and Clausen (); Stovin et al (); Stovin, Poë, and Berretta (); Ahiablame, Engel, and Chaubey (); Carson, Marasco, Culligan, and McGillis (); Wadzuk et al (); Fassman‐Beck, Voyde, Simcock, and Hong (); Vanuytrecht et al (); Nawaz, McDonald, and Postoyko ()…”

International Low Impact Development Conference 2015

“…Evapotranspiration rates from the lysimeter are calculated on a daily basis. Wadzuk et al (2013) determined that ET can be calculated from a water balance as ET lys = W 0 − W 24 + P − Q r (1) where W 0 is the weight of the lysimeter at midnight beginning of day, W 24 is the weight of the lysimeter at midnight end of day, P is weight of precipitation, and Q r is overflow. Overflow is estimated by taking the weight at the beginning of the day summing with the weight of precipitation, and subtracting the weight max of the year (weight of the lysimeter when it is completely full of water) if this value is positive it is taken as overflow, if it is negative it is set to zero (no overflow).…”