The Subsurface of our Cities is the True Primary Infrastructure

Extreme climate events are affecting territories that are already vulnerable due to the nature of their subsurface. This is not only about heavy rainfall or heatwaves. This is the result of the interaction between climate extremes and urban geology.

Although we are only at the start of 2026, serious cases have already emerged across Europe:

• Niscemi, Italy, where the combination of local geological characteristics and intense meteorological events associated with Cyclone Henry amplified instability of an enormous landslide and risks for the built environment.
• Andalucia, Spain, where many urbanised areas are increasingly exposed to climate extremes that, combined with geological conditions, have severely affected urban areas and infrastructures, as seen during Storm Leonardo).
• Coimbra, Portugal, where extreme events caused several floods in urbanised areas.

These are not isolated cases. They are clear signals that Europe must recognise a fundamental truth: the subsurface of our cities is the true primary infrastructure.

All other secondary infrastructures – our homes, roads, railways, public buildings and essential services – rest upon it or are embedded in it (as it is the case for the supply infrastructure).

If we do not understand and correctly manage this primary infrastructure, everything else becomes more fragile.

For years, the Urban Geology Expert Group has been working to bring this awareness to the centre of urban policies. Through the UGF – Urban Geo-Climate Footprint methodology, promoted by ISPRA within EuroGeoSurveys, we make geological information about urban settlements and the potential criticalities arising from it accessible, understandable, and immediately usable for citizens and decision-makers.

Our message is clear: Be aware, Be prepared, Be safe

• We need greater awareness of the subsurface in our cities.
• We need planning based on geological knowledge.
• We need local administrators equipped with the right tools and expertise.
• We can no longer afford to consider the subsurface as something invisible or as a general “grey zone” beneath our feet!
• It is the foundation of urban safety, climate resilience, and future sustainability.
• We call on European institutions, national governments and local authorities to systematically integrate geological knowledge into climate adaptation strategies and urban planning.
• The time for awareness is now!

Francesco La Vigna, ISPRA, Chair of EGS Urban Geology Expert Group

Beatriz Benjumea Moreno, IGME-CSIC, Deputy Chair of EGS Urban Geology Expert Group

Rouwen Lehné, HLNUG, Deputy Chair of EGS Urban Geology Expert Group

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