Main results 1
Main results:
Impacts are less pronounced than those usually observed at the building scale because they depend on the green roof area, representing only 34% of the basin area.
Green roof appears to significantly impact urban runoff in terms of peak discharge and runoff volume depending on precipitation and the initial state of the substrate saturation.
These reductions can reach around 80% for the more favorable cases (the smallest events with a low initial saturation).
Green roof is more efficient for standard and short rainfall events than for long extreme events for which the substrate could be rapidly saturated.
Green roof should be more adapted to reduce the impacts of summer rainfall event than winter ones because evapotranspiration is higher in summer. The probability to have low initial state of the saturation substrate should be higher.
