Evaluating Green Infrastructure for Climate-Driven Urban Flood Resilience: Insights from Peshawar City, Pakistan

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Urban flooding presents a critical challenge worldwide, driven by rapid urbanization, inadequate drainage systems, and climate change. In developed countries, aging infrastructure and increasing precipitation intensities worsen flood risks. In contrast, developing nations struggle with uncontrolled urban sprawl, poor stormwater and waste management, and limited financial resources for flood mitigation. Pakistan’s major cities, including Peshawar, frequently experience urban flooding, resulting in infrastructure damage, economic loss, and disrupted livelihoods. This study explores the role of Green Infrastructure (GI) in enhancing urban flood resilience in Peshawar, using Khamosh Colony as a case study which faces frequent flooding due to poor drainage, and encroachments. Climate projections (2015–2100) were analyzed for two Shared Socioeconomic Pathways (SSPs) using the best-performing Global Climate Models (GCMs), revealing a significant increase of 10–40% in precipitation for smaller return periods (2–10 years) and up to 61.66% and 81.35% increases for 200-year events under SSP2-4.5 and SSP5-8.5, respectively, consistent with severe flooding observed in 2022. Using SWMM, standalone and combined GI strategies were assessed for their flood mitigation potential under 2- and 5-year return period rainfall events, including future climate scenarios. Economic feasibility was evaluated using 2024 market rates while community preferences were assessed through surveys conducted in Peshawar via Kobo Toolbox. Among the options, permeable pavement (standalone) and permeable pavement with bioretention (combined) emerged as the most effective and preferred solutions. A novel aspect of this study is the integration of 1D hydrodynamic modeling with 3D visualization in SWMM and GIS, providing stakeholders with an intuitive understanding of pre- and post-GI flood scenarios. This enhances public awareness, facilitates participatory decision-making, and supports investment prioritization. By addressing the lack of integrated flood modeling and decision-support tools in Pakistan, this research fills a key gap and offers a replicable framework for evidence-based, climate-adaptive, and community-inclusive urban planning to build flood-resilient cities.