Creating green infrastructure design guidelines using pre-design parameter optimization

Urban areas across the country are facing serious flooding and water quality issues, causing significant environmental, economic, and social effects on communities. As the climate changes, increased precipitation and more frequent heavy rain fall events will exacerbate these problems, further degrading the environment. Green infrastructure can mitigate these issues, resulting in a variety of benefits, and has been actively implemented since the late 1990s. There is a significant amount of literature examining the post-occupancy effects of green infrastructure projects, yet there exists little optimization-based guidance on the best design procedures to maximize and balance its economic and environmental benefits. This research created a set of design guidelines for the design of green infrastructure systems, based on pre-design parametric (or sensitivity) analysis. Three models retrieved from the Landscape Performance Series from the Landscape Architecture Foundation were examined and analyzed, creating a hierarchy of the most important types of green infrastructure facilities involved in the design process. The created guidelines were applied to a design of a 659 acre site in Lansing, Michigan, USA, spanning the Grand River's course through Downtown, to confirm their validity, practicability, and functionality. Accordingly, post-design performance was calculated using a series of landscape performance models. The results showed that the most important green infrastructure facilities in reducing runoff while balancing capital and maintenance costs were rain gardens, street planters, infiltration basins, wetlands, and vegetation filter strips. The design framework was used to create a design of the site, leading to a 50% reduction in annual runoff volume, 9 - 16% reductions in water pollution levels, and significant carbon sequestration. The study provides a new way to gain sitespecific insights into the design of green infrastructure projects across the nation.