[Climactions project. Environmental, socioeconomic, and territorial vulnerability in 5 Italian cities].

Objectives: to identify environmental, socioeconomic, and territorial characteristics in five urban areas (Turin, Bologna, Rome, Bari, Palermo) and to identify areas characterized by high environmental and socioeconomic vulnerability.

Design: geographical study.

Setting and participants: study domain on five Italian cities, each city was characterized at the urban-area level.

Main outcome measures: for each urban area or neighbourhood, multiple spatial indicators were constructed concerning the main environmental (air pollution, urbanisation, temperature, altitude and presence of rivers and watercourses, greenery, road and rail networks), and socioeconomic (deprivation index) aspects. These characteristics have been synthesised into a composite indicator with a geographically weighted principal component analysis in order to characterise environmental and socioeconomic vulnerability in a single measure that can be more easily interpreted compared to a set of individual indicators.

Results: the involved cities have numerous databases suitable for mapping the main environmental and socioeconomic characteristics. Turin is the most populous of these cities and the one which has the highest average daily PM10 value (29.7±1.4 µg/m3). Together with Palermo, it is the city with the highest density of local roads. Data on residential land cover show a South-North gradient, from 50% in Palermo and Bari to 24,5% in Rome. Low-density residential areas prevail in all cities. The synthetic value of the indicator captures the spatial variability of the territory, highlighting the areas of greatest urban vulnerability in each city under study. Bologna and Roma are the cities with the highest percentage of residents in the high environmental, climate, and socioeconomic vulnerability level, respectively 38% and 29%, while Bari and Palermo show the highest fraction of population living in low vulnerability areas.

Conclusions: in this study, five Italian cities were characterised from an environmental, socioeconomic, and spatial perspective. Furthermore, through the use of a synthetic indicator of socioeconomic environmental exposure, the most vulnerable areas were identified. This indicator provides immediate and effective information to support policies to protect health and combat environmental and social risk factors in the area.