Battle of centralized and decentralized urban stormwater networks: From redundancy perspective. (15th August 2022)

• Record Type: Journal Article
• Authors: Hesarkazzazi, Sina; Bakhshipour, Amin E.; Hajibabaei, Mohsen; Dittmer, Ulrich; Haghighi, Ali; Sitzenfrei, Robert
• Is Part Of: Water research. Volume 222(2022)
• Publication Date: 2022-08-15
• Subjects: Urban stormwater networks -- Graph theory -- Layout decentralization -- Resilience -- Redundancy; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2022.118910
• Languages: English
• ISSNs: 0043-1354

Abstract

Highlights: Impact of redundancy on resilience under functional and structural failure is addressed. A cost-effective and easy-to-implement method to enhance resilience is developed. A tailored graph-theory measure for optimal placement of redundant paths is proposed. Importance of topological decentralization is highlighted under extreme rainfall events. Redundant flow pathways could improve resilience by up to 8% under functional failure. Abstract: Recent research underpinned the effectiveness of topological decentralization for urban stormwater networks (USNs) during the planning stage in terms of both capital savings and resilience enhancement. However, how centralized and decentralized USNs' structures with various degrees of redundancy (i.e., redundant water flow pathways) project resilience under functional and structural failure remains an unresolved issue. In this work, we present a systemic and generic framework to investigate the impact of adding redundant flow paths on resilience based on three strategies for optimal centralized versus decentralized USNs. Furthermore, a tailored graph-theory based measure (i.e., eigenvector centrality) is proposed to introduce redundant paths to the critical locations of USNs. The proposed framework is then applied to a real large-scale case study. The results confirm the critical role of layout decentralization under both functional (e.g., extreme precipitation events), and structural failure (e.g., pipe collapse). Moreover, the findings indicate that the implementation of redundant paths could increase resilience performance by up to 8% under functional failure without changing the network's major structural characteristics (i.e., sewer diameters, lengths, and storage capacity), only by leveraging the effective flow redistribution. The scheme proposed in this study can be a fruitful initiative for further improving the USNs' resilience during both planning and rehabilitation stages.