Design, implement, and evaluate urban flood-resilient green corridors in a coastal city

Thesis Abstract

Designing and evaluating urban flood-resilient green corridors in coastal cities addresses the escalating risk of flooding and ecosystem degradation in rapidly urbanizing coastal zones, where impervious surfaces and heightened storm intensity exacerbate flood exposure and urban heat. This study aims to design, implement, and evaluate a network of flood-resilient green corridors that integrate blue-green infrastructure to enhance stormwater management, biodiversity, and residents’ resilience. The specific objectives are (1) to diagnose hydrological and urban form drivers of flood risk in a selected coastal metropolis; (2) to develop a costed design blueprint of interconnected green corridors incorporating permeable pavements, bioswales, rain gardens, and mangrove/shoreline buffers aligned with land-use planning; (3) to pilot a representative corridor module within the urban fabric and implement master planning and community engagement processes; (4) to evaluate hydrological performance, ecological benefits, and social acceptance pre- and post-implementation; and (5) to formulate policy, governance, and maintenance frameworks for scalable replication. The study adopts a mixed-methods design underpinned by the Urban Ecological Resilience and Green Infrastructure theories, drawing on the Social-Ecological Systems (SES) framework and the Ecosystem Services approach to interpret outcomes. The population comprises municipal planning agencies, property developers, and residents in both immediate and downstream neighborhoods of the pilot corridor. A stratified sampling approach selects 240 households for surveys, 30 key informants from agencies and NGOs, and 12 watershed sub-units for ecological and hydrological monitoring. Data collection instruments include hydrological sensors (flow, water level, groundwater indicators), soil and vegetation surveys, GIS-based land-use and drainage-network analyses, and semi-structured interview guides and household questionnaires. Instrument validity is established through pilot testing, expert review, and triangulation, with reliability assessed via Cronbach’s alpha for survey scales and test-retest procedures for interview protocols. The intervention comprises a modular corridor design integrating permeable pavements, engineered soil media, rainwater harvesting features, constructed wetlands, tree canopies for interception, and coastal buffer vegetation, connected through a physio-ecological network. The pilot module is implemented over a 12-month period withBaseline and Outcome phases to capture pre- and post-intervention conditions. Data analysis employs hydrological modelling (SWMM) to simulate peak discharge reductions and runoff coefficients, paired with a difference-in-differences approach to attribute changes to the intervention. Spatial analyses using GIS and network analysis assess corridor connectivity, while structural equation modelling (SEM) tests relationships among landscape design, hydrological performance, biodiversity indices, and social acceptance. Thematic analysis of interviews and participatory workshops elucidates stakeholder perceptions and identifies implementation barriers. A cost-benefit analysis evaluates the economic viability, incorporating maintenance costs, avoided flood damages, and ecosystem-service monetization. The study also tests the mediating role of community engagement using mediation analysis within the SEM framework. Expected findings include substantial reductions in surface runoff volumes and peak discharge rates within the pilot corridor, enhanced infiltration and groundwater recharge, measurable increases in native biodiversity and pollinator activity, and improved ambient thermal comfort. Social outcomes are anticipated to reflect higher risk awareness, greater willingness to adopt green infrastructure, and stronger sense of place among residents. The research is expected to demonstrate that integrated blue-green corridors provide co-benefits across flood risk reduction, ecological integrity, and social well-being, with effects amplified through active governance and long-term maintenance planning. The contribution to knowledge lies in providing a practically tested, scalable blueprint for flood-resilient green corridors in coastal urban contexts, advancing understanding of hydrological-ecological-social interactions in green infrastructure outcomes, and offering an operational framework for policy integration, funding pathways, and multi-stakeholder governance. The study concludes with actionable recommendations for design standards, payment-for-ecosystem-services schemes, governance models, and monitoring protocols to support replication in similar coastal cities facing storm surge and sea-level rise, while outlining areas for further investigation such as long-term climate adaptation trajectories and longitudinal social indicators.