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 and volunteered geographic information, have enabled comprehensive regional exposure-hazard analyses. However, their intersection with physical vulnerability remains underexplored to translate into risk dynamics at the neighbourhood-to-city scale. To investigate the utility of high-resolution multi-temporal building height data from the Google Open Buildings 2.5D Temporal dataset and publicly available Copernicus Sentinel-2 imagery for projecting exposure and vulnerability through probabilistic graph deep learning, we evaluated the multi-hazard urban risk dynamics under the compounding effects of earthquake and flood in Quezon City, Philippines, as a case study. We derived annual development profiles in built-up area, building materials (wood, masonry, concrete, and steel), damaged floor area, casualty estimates, and multi-hazard displacement spanning 2016–2030, while emphasising key uncertainties in regional exposure and vulnerability modelling that remain challenging in practice. Variability in growth trajectories across 142 neighbourhoods (locally known as barangays) reflects disparities in the affordability of building materials and identifies strategic hotspots for housing retrofit programmes and healthcare demand planning. A comparison against the existing geospatial exposure database further reveals opportunities to advance the current state of practice in building stock attribution. In conclusion, rapidly urbanising cities such as Quezon City have experienced uneven trajectories of multi-hazard risk across neighbourhoods in recent years, underscoring the need for sustained scientific scrutiny and rigorous validation of CDRA to support effective prospective disaster risk management at scale.