Assessing Geological and Climatic Pressures on Human Settlements Through the Urban Geo-Climate Footprint (UGF). Application to 21 Regional Capital Italian Cities

Urban areas are increasingly affected by geological and climate-driven processes that influence their safety, functionality, and long-term resilience. Conventional sustainability indicators mainly focus on anthropogenic impacts on the environment, while the role of subsurface conditions and physical processes shaping urban vulnerability remains underrepresented. To address this gap, the Urban Geo-climate Footprint (UGF) introduces an inverse perspective, assessing how geological and climatic factors exert pressure on urban systems. The methodology is based on the breakdown of geological effects into five drivers, Geology, Deep Geological Processes, Surface Processes, Exogenous and Climatic Processes, and Subsurface Anthropogenic Pressure. These drivers, in the derived tool, are articulated into 22 parameters evaluated from public datasets and expert judgment. These parameters are combined into a synthetic, standardised, reproducible and comparable index, the UGF Score Index (UGF-SI), ranging from 0 to 500 which enables direct comparison across cities and contexts. The application to 21 Italian cities highlights distinct spatial patterns, dominant drivers, and groups of cities facing similar geo-climatic challenges. The UGF framework represents a significant advancement in urban geoscience, supporting urban planning, risk awareness, and climate adaptation strategies by enhancing the understanding of subsurface-related pressures and promoting informed decision-making.