Green Roof Curve Number Soil C

Elements in green roofs subject to uncertainty considered are rainfall characteristics i e.

Green roof curve number soil c.

N2 curve number cn is well known by hydrologists for estimating rainfall induced runoff from a catchment. The green roof used to establish the curve number was composed of a 3 deep soil 55 expanded slate 30 sand and 15 organic matter. Amount and inter event dry period soil plant climate. 2007 derived curve numbers for studied green roofs.

94 92 88 85 77 reprinted from the 2000 maryland stormwater design manual mde 2000 2009 chapter 5 p. P q s q p actual retention potential retention actual runoff total rainfall where cn 25400 254 s. The curve number for infiltration trench is adapted to be 61 in accordance with the. Despite substantial performance evidence in the literature the lack of a curve number cn or volumetric runoff coefficient c v to apply to prescribed methodologies for planning and regulatory submissions may be perceived as a barrier for implementation.

Modeling of green roof as a shallow figure 3b. The soil had a total porosity of 50 6. 5 42 since 2009 the number of different green roof systems on the market has expanded greatly. Paired rainfall runoff data were analyzed for up to 21 living roofs with varying.

Impervious surfaces are assigned cn of 98. T1 assessing curve number uncertainty for green roofs in a stochastic environment. The resulting curve number was 86 compared to 98 for an impervious roof. Influence of growth media soil water retention 16 18 20 note.

Effective cns for extensive green roofs roof thickness in. The curve number for green roofs for large rainfall events is given as 84 fassman beck et al 2015. 2 april 2010 prepared for the southern california stormwater monitoring coalition in cooperation with the state water resources control board by the low impact development center inc. For a more detailed and complete description of land use curve numbers refer to chapter two 2 of the soil conservation service s technical release no.

The site was in athens georgia annual rainfall of 48 5 inches. 2 3 4 6 8. Curve number cn method is stating a following relationship between rainfall and runoff. Au huang w.

55 210 vi tr 55 second ed june 1986. No runoff from first storm when n 1 5. Au tung y. Au you l.