An Integrated Physical Diagnosis of Compound Climate Risks for Urban Sustainability in Port Said Region, Egypt

Deltaic cities are global hotspots of climate change vulnerability due to their low elevation, high population density, and concentration of critical economic infrastructure. This study presents an integrated physical diagnosis of compound climate risks for the Port Said Urban Region, a strategic gateway at the northern terminus of the Suez Canal in Egypt’s Nile Delta. We quantify seven key climatic and climate-related drivers—coastal erosion, flooding, saltwater intrusion, abiotic stress, drought, heat waves, and port downtime/siltation—across three timeframes: the present day, the near-term (2030–2040), and the long-term (2050–2070). The analysis compares a moderate-emissions scenario (Representative Concentration Pathway, RCP 4.5) with a high-emissions scenario (RCP 8.5), utilising downscaled climate projections, hydrodynamic models, and remote sensing data. Our findings reveal that the region’s high rate of land subsidence significantly amplifies the threat of relative sea-level rise, accelerating risk timelines. Results indicate a convergence of high erosion, flooding, and saltwater intrusion hazards, forming a ‘critical risk triangle’ that spatially overlaps with major planned urban and industrial expansion zones. This misalignment between development trajectories and future climate realities highlights a potential for large-scale maladaptation. The paper concludes by deriving a framework of actionable, context-specific adaptation strategies, including risk-informed spatial planning, nature-based solutions, and infrastructure resilience measures, to guide Port Said’s transition towards urban sustainability. The replicable methodology provides a valuable diagnostic tool for other medium-sized, globally significant coastal cities facing similar compound climate threats.