Multi-scale investiGation of natuRe-basEd solutions for thE mitigatioN of urban heat and POLlution ISland (GREEN-POLIS)

Abstract

The overall objective of GREEN-POLIS is to provide scientific evidence of the impacts of different NBSs on the urban microclimate with the aim to establish a solid scientific basis for the use of NBSs in adaptation and mitigation strategies for the urban heat island (UHI) and urban pollution island (UPI). A. Assessment of currently-available NBSs to mitigate UHI and UPI. Expected results: B. Evaluation of the beneficial effects and unintended consequences of urban NBSs. C. Upscaling of selected NBSs to the real case of Bologna.

Results achieved

: The GREEN-POLIS project (Multi-scale investiGation of natuRe-basEd solutions for thE mitigatioN of urban heat and POLlution ISland) was launched with the goal of deepening scientific understanding of the effects of Nature-Based Solutions (NbS) on the mitigation of two of the main environmental challenges facing contemporary cities: the urban heat island effect and the urban pollution island effect. The project addresses this issue with a strongly interdisciplinary and multiscale approach, combining atmospheric physics, computational fluid dynamics, meteorological modeling, and laboratory experiments. Increasing urbanization, combined with the effects of climate change, is leading to rising temperatures in urban areas, more frequent heat waves, and deteriorating air quality. In this context, NbS represent one of the most promising tools for enhancing cities’ ability to adapt. However, the effectiveness of various solutions (such as urban vegetation, water bodies, and other green and blue infrastructure) depends heavily on the city’s geometric characteristics, meteorological conditions, and the interactions between thermal and dynamic processes. The GREEN-POLIS project focuses on the city of Bologna and aims to provide a quantitative and scientifically robust assessment of the benefits and potential side effects associated with the implementation of NbS. The methodology developed is based on a multiscale approach that links the behavior of atmospheric flows at the street and urban block scales with the observable effects at the citywide scale. The research activities integrated high-resolution laboratory experiments, computational fluid dynamics simulations using Large-Eddy Simulation, and the development of new parameterizations for mesoscale weather models (Weather Research and Forecasting). This integration made it possible to transfer the knowledge gained from idealized cases to realistic applications. One of the project’s key scientific findings is that it has clarified the role of NbS in urban ventilation processes, pollutant dispersion, and the thermal regulation of urban spaces. High-resolution numerical simulations have made it possible to quantify how specific urban configurations can facilitate or hinder the removal of air pollutants, highlighting that the effectiveness of NbS depends not only on their presence but also on their proper design and spatial placement. The project also developed new parameterizations for representing Nature-Based Solutions within the Weather Research and Forecasting (WRF) meteorological model, enabling a more realistic simulation of urban morphology. The project’s activities have resulted in numerous scientific publications in peer-reviewed international journals on urban ventilation simulation, pollutant dispersion, urban microclimate modeling, Large-Eddy Simulations, WRF model parameterizations, and the effectiveness of Nature-Based Solutions. Particular attention has also been devoted to scientific dissemination and technology transfer, as well as participation in international conferences and the publication of results via open access. All information about the project, including a description of research activities, deliverables, news, events, and scientific publications, is available on the official website: https://site.unibo.it/greenpolis/en

Project details

Unibo Team Leader: Carlo Cintolesi

Unibo involved Department/s:
Dipartimento di Fisica e Astronomia "Augusto Righi"

Coordinator:
ALMA MATER STUDIORUM - Università di Bologna(Italy)

Total Eu Contribution: Euro (EUR) 190.000,00
Total Unibo Contribution: Euro (EUR) 76.000,00
Project Duration in months: 24
Start Date: 28/09/2023
End Date: 28/02/2026