Multi-criteria Prioritization of Flood Risk Management Strategies for Sustainable Urban Development in the Philippines

Abstract

Urban flooding poses significant challenges to public safety, environmental sustainability, and socio-economic development, particularly in rapidly urbanizing cities in the Philippines, such as Calamba City. Effective prioritization of flood risk management strategies is therefore critical to support evidence-based urban planning and climate adaptation. This study applies a multi-criteria decision analysis (MCDA) framework integrating the Weighted Sum Model (WSM) and the Analytic Hierarchy Process (AHP) to systematically evaluate four flood management strategies: Infrastructure-Based Solutions (INFRA), Nature-Based Solutions (NBS), Early Warning and Evacuation Systems (EEWS), and Business-As-Usual (BAU). Evaluation criteria encompassed hydrological effectiveness, environmental sustainability, socio-economic benefits, implementation feasibility, and long-term resilience. Results from WSM ranked INFRA highest (65.00), reflecting its strong performance in flood control, public safety, and economic co-benefits, followed by NBS (44.95), which demonstrated substantial advantages in ecosystem services, carbon mitigation, and cost efficiency. Conversely, AHP slightly prioritized NBS over INFRA, underscoring its long-term sustainability and adaptive capacity. EEWS ranked lower under both methods due to its limited structural impact despite high cost-effectiveness and responsiveness. The findings highlight the value of hybrid flood management pathways that integrate gray and green infrastructure alongside early warning systems. This study provides a robust decision-support framework for urban planners, local governments, and policymakers in advancing sustainable, climate-resilient, and inclusive flood risk management in Philippine urban settings.