Both of the roofs have considered with extensive green roofs having a 150 mm depth of surface layer for root growth shown in fig.
Vegetation volume fraction green roof.
1 as gr1 and gr2.
This is the volume occupied by stems and leaves not their surface area coverage.
Fraction of the area above the surface that is filled with vegetation.
Control name lid type layer parameter value gr your initial green roof surface berm height 3 vegetation volume fraction 0 2 surface roughness 0 1 surface slope 1 0 soil thickness 6 porosity 0 5 field capacity 0 2 wilting point 0 1 conductivity 0 5 conductivity slope 10 suction head 3 5 drainage mat thickness 1 void fraction 0 5 roughness 0.
The gradient of the surface slope.
Green roofs are popular measures for stormwater management while also providing a set of other positive aspects to local environment ranging from reduced energy consumption for buildings reduction in heat island effects increase in urban habitats and bringing visual improvements to urban areas besir and cuce 2018 oberndorfer et al 2007 saadatian et al 2013.
24 control name lid type layer parameter value gr your initial green roof surface berm height 3 vegetation volume fraction 0 2 surface roughness 0 1 surface slope 1 0 soil thickness 6 porosity 0 5 field capacity 0 2 wilting point 0 1 conductivity 0 5 conductivity slope 10 suction head 3 5 drainage mat thickness 1 void fraction 0 5 roughness 0.
Besides this value is calculated by the area and depth of the grs in this study.
Porosity the volume of pore space relative to total volume of soil as a fraction.
Modelling results demonstrated that the conversion of 30 of roof area to green roof 10 of green areas to rain gardens and 35 of paved areas to permeable pavement could increase the baseline volume capture ratio from 59 9 to 82 2 indicating that sponge city goals can be met within the case study area with realistic levels of lid.
One reason for its low cost effectiveness is that green roof does not treat.
An extensive green roof is most suitable for implementation at the individual level or small scale which provides the best cost benefit ratio with the least maintenance as compared to the intensive green roof.
Vegetation volume fraction the fraction of the volume within the surface storage depth filled with vegetation.
Manuscript title a modeling study of the interflow in the green roof.
2 the volume of the rainwater tanks is better larger than 0 045 m 3 for per unit area m 2 of grs.
Green roofs also referred to as vegetated roofs eco roofs and roof gardens consist of a layer of vegetation that covers an otherwise conventional flat or moderately pitched roof.
Surface roughness manning s n manning s n for overland flow.
The cost effectiveness of green roof expressed as percentage of peak runoff reduction per thousand dollars and volume of peak runoff reduction per thousand dollars i e 0 02 10 3 us and 0 02 l 10 3 us s is the least among the three lid practices.