Towards Prospective Disaster Risk Management: Mapping Multi-hazard Urban Risk Dynamics Driven by Evolving Exposure and Vulnerability via Earth Observation

Joshua Dimasaka , Fouad Bendimerad, Renan Ma. Tanhueco, Christian Geiss, Emily So

As local governments increasingly adopt geospatial Climate and Disaster Risk Assessment (CDRA) to inform prospective public policy, the reliability of existing static risk intelligence is challenged by the continuous evolution of building exposure, population distribution, and physical vulnerability. Recent multi-temporal datasets of the built environment, derived from Earth Observation, have enabled comprehensive regional exposure-hazard analyses, yet their intersection with physical vulnerability remains underexplored. This study evaluates multi-hazard urban risk dynamics under the compounding effects of earthquake and flood in Quezon City, Philippines, using high-resolution multi-temporal building height data and Sentinel-2 imagery for projecting exposure and vulnerability through probabilistic graph deep learning. To extend the current CDRA and static Barangay Vulnerability Index (BVI), we present annual development profiles in terms of compound annual growth rate (CAGR) of its existing risk metrics spanning 2016–2030, covering building exposure, physical vulnerability, and earthquake-flood risk indicators. Against a baseline of 41,935 injuries for hospitalization and 12,494 fatalities, our projections indicate annual increases of up to +298 injuries and +85 fatalities, with 24 barangays identified with high earthquake- and high flood-induced displacement growth. Variability in growth trajectories across 142 barangays reflects the documented northward expansion of urban development, contrasting with redevelopment-driven patterns in the highly urbanized southern districts. Overall, our findings highlight spatially uneven trajectories of multi-hazard risk, underscoring the need for participatory validation with planners and policymakers to translate these spatiotemporal risk profiles into representations that are accessible, actionable, and impactful for prospective disaster risk management in cities undergoing rapid urbanization.