KEYNOTE LECTURE

Giovanna Venuti

Politecnico di Milano, Italy

Within the framework of the “Space It Up!” project, funded by the Italian Space Agency (ASI) and the Ministry of University and Research (MUR), this work addresses the increasing impact of urban heat islands (UHI) in the context of more frequent, intense, and persistent heatwaves. The study focuses on urban and suburban environments, aiming to advance the understanding, monitoring, and modelling of urban thermal patterns and their driving factors.

A comprehensive analysis of heatwaves and thermal stress across Italy was carried out by combining very-high-resolution (2.2 km) climate reanalysis data (VHR-REA_IT) with long-term station observations over the 1981–2024 period. This multi-decadal dataset enables a robust assessment of spatial variability and long-term trends in extreme heat conditions.

To better resolve urban-scale processes, machine learning regression models were developed to predict near-surface air temperature by integrating in situ measurements—from both official and crowdsourced networks—with GIS and Earth Observation (EO) features. These models produce high-resolution temperature maps at different times of the day, capturing the diurnal evolution of the UHI effect.

In parallel, Local Climate Zones (LCZs) were mapped using hyperspectral PRISMA imagery, urban canopy parameter (UCP) datasets, and machine learning techniques. The workflow introduces improvements in the automation and quality control of training and validation samples, based on geometric properties, class balance, and UCP statistics, with data processing streamlined through Google Earth Engine and Python-based tools.

Finally, hyperspectral unmixing of PRISMA and DESIS data was employed to estimate the fractional composition of urban surface materials and investigate their relationship with land surface temperature derived from Landsat 8/9 thermal infrared observations. Validation activities are currently ongoing using airborne hyperspectral and thermal data collected over Milan during the August 2025.

Giovanna Venuti is Associate Professor of Geomatics at Politecnico di Milano, Department of Civil and Environmental Engineering, where she has been serving since 2015. She holds a PhD in Geodetic and Topographic Sciences from Politecnico di Milano and a MSc in Civil Engineering (summa cum laude) from Politecnico di Torino. Her research focuses on stochastic modelling of geodetic and environmental observations, with particular emphasis on satellite-based Earth observation and GNSS applications. Her main scientific contributions include satellite radar altimetry for sea surface estimation, gravity field modelling, GNSS-based atmospheric water vapour retrieval, and the use of opportunistic observations for meteorological applications such as convective rainfall prediction. In recent years, her research has expanded towards the integration of multi- and hyperspectral Earth Observation data for urban climate studies, including the analysis of the Urban Heat Island (UHI) phenomenon. She has extensive experience in national and international research projects, serving as Principal Investigator and Work Package Leader in several initiatives funded by the European Commission, ESA, ASI, and national programmes, including PRIN and PNRR projects. Recently she was Principal Investigator of a PRIN project ICREN on convective rainfall nowcasting and was involved in projects addressing urban climate and Earth observation, like the still ongoing Space It Up project funded by the Italian Space Agency and the Ministry of University and Research. At Politecnico di Milano, she teaches courses in geospatial data analysis, observation processing, and statistical methods, and she is a member of the PhD Board in Environmental and Infrastructure Engineering. She currently coordinates the MSc programme in Geoinformatics Engineering. She is co-author of more than 80 scientific publications in international journals and conference.