Coastal cities face growing risks from sea-level rise and extreme weather events, which are exacerbated by urbanization and socio-economic vulnerabilities. The project FRACCEO aims to develop a globally transferable methodology that combines Earth Observation (EO) data, particularly Essential Climate Variables from ESA’s Climate Change Initiative, with hydrodynamic modeling to improve coastal water level forecasts and urban flood risk assessments. The approach will be tested in Hamburg and Beira, representing contrasting geographic and socio-economic contexts, and evaluated for applicability to cities in the Global South. The project supports ESA’s Climate Change Initiative and contributes to the upcoming IPCC Special Report on Climate Change and Cities by addressing critical knowledge gaps and demonstrating the added value of EO data.

DGFI-TUM plays a central role in developing the scientific core of the methodology. Its contribution focuses on detecting sea-level and sea-state extremes from EO data, particularly satellite altimetry, and integrating these observations into high-resolution hydrodynamic models. DGFI-TUM will also ensure that outputs are referenced to a common vertical datum, a crucial step for consistency across datasets and models. These tasks are fundamental for improving uncertainty quantification and validating EO-hydrodynamic approaches. Leveraging its internationally recognized expertise in coastal altimetry and remote sensing, DGFI-TUM will advance the state of the art in linking EO data with operational flood risk modeling.

The project is structured into five work packages: scoping and stakeholder engagement, methodology development (led by DGFI-TUM), implementation and validation, synthesis and roadmap development, and outreach. By co-developing methods with stakeholders and publishing algorithms and workflows openly, the project ensures usability and fosters future operational uptake. Ultimately, this work will provide a scientific foundation for climate services tailored to urban needs, enhance resilience planning, and inform global assessments such as the IPCC report.

More information is available on the project website: https://climate.esa.int/en/supporting-the-paris-agreement/fracceo/