Sensitivity Analysis Using the SWMM LID Control for an Extensive Green Roof in Syracuse, NY

Green roofs are a popular form of sustainable drainage infrastructure. They provide many environmental benefits, such as reducing peak urban stormwater runoff by enabling retention and evapotranspiration similar to natural conditions. Each green roof has unique hydrologic behavior based on physical properties of its growth medium, types of vegetation, structural design, and climate. To improve the application of green roof technology at a site, there is a need to predict stormwater mitigation for several designs before commencing green roof construction. The Storm Water Management Model (SWMM) includes a low impact development control module which makes it possible to model the hydrologic performance of a green roof by directly defining the physical characteristics of its layers. In this study we compare the outputs of the SWMM model with hydrologic performance data from a large extensive green roof in Syracuse, NY from April 2017 to October 2017. Our objectives are to evaluate the performance of SWMM as a long-term modeling software appropriate for predicting the hydrologic performance of a green roof, and to explore changing parameters that might improve hydrologic performance when designing future green roofs. It is expected that this work will help designers of green roofs in climates similar to those of Central NY. In the future, more extensive hydrologic data will be obtained to enable better assessment of SWMM as a tool to help design green roofs.