Green Infrastructure for Sustainable Stormwater Management in an Urban Setting Using SWMM-Based Multicriteria Decision-Making Approach

A study is presented for the assessment of different stormwater green infrastructure (SGI) for sustainable stormwater management, both stand-alone and in combination, in the rapidly developing city of Gurugram, India. A decision-making framework was developed for ranking the SGI based on five criteria (social, economic, environmental, technical, and legal and political) encompassing two quantitative and 12 qualitative subcriteria. The assessment of the application of SGI was carried out using Storm Water Management Model (SWMM) software and an expert survey involving participants from varied areas of expertise. The survey outcome determined the criteria weight by employing the analytic hierarchy process method, where technical and social criteria were given the highest (0.37) and the lowest (0.11) weight, respectively. Further, peak flow reduction potential was the most favored subcriteria (82%), while aesthetics was the least favored (58%). The prioritization of a set of predefined alternatives was carried out using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method. Results indicated that the relative closeness coefficient value for a combination of SGI, vegetated swales plus permeable pavements was 0.93, whereas for green roofs plus permeable pavements it was 0.84, and these were the most efficient alternatives to mitigate urban flooding in the city. The proposed SWMM-based TOPSIS approach can be helpful to decision makers and government bodies in the selection of SGI for urban stormwater management.