An integrated physical diagnosis of compound climate risks for urban sustainability in Port Said Region, Egypt

Abstract

Abstract Deltaic cities are highly vulnerable to climate change due to low elevation, dense populations, and critical infrastructure. This study presents an integrated assessment of compound climate risks in the Port Said Urban Region, Egypt, evaluating seven key hazards—coastal erosion, flooding, saltwater intrusion, abiotic stress, drought, heat waves, and port disruption—across present, near-term (2030–2040), and long-term (2050–2070) horizons. Using CMIP5 downscaled projections, hydrodynamic reanalysis, and remote sensing, the analysis compares RCP 4.5 and RCP 8.5 scenarios. Models are calibrated against 50 years of shoreline change and validated with tide gauge data ( r  = 0.83). Results highlight rapid land subsidence (4.1–5.3 mm/year) as a critical risk amplifier, accelerating sea-level impacts. A “Critical Risk Triangle” of overlapping hazards coincides with major development zones, placing significant investments at risk. The study proposes risk-informed planning and adaptive strategies, offering a replicable framework for vulnerable coastal cities.