Green infrastructure (GI) encompasses natural and semi-natural areas that are strategically planned and managed to enhance biodiversity and provide a wide range of ecosystem services. As a nature-based solution, GI plays a key role in mitigating and adapting urban areas to climate change. Through its multifunctionality, GI contributes to regulating environmental processes across multiple spatial scales, contributing to improved environmental quality and human well-being.

In cities, GI elements such as street trees and urban parks reduce air temperatures and human thermal stress through shading and evapotranspiration. However, the delivery of these ecosystem services strongly depends on vegetation health, which in urban environments is constrained by multiple stressors, including elevated air temperatures, limited water availability, complex radiation regimes, restricted rooting and canopy space, and air and soil pollution. These challenges are intensified by the increasing frequency and intensity of extreme climate events, such as heat waves and droughts, which are often amplified in urban areas. Such events can compromise ecosystem functioning and reduce the capacity of GI to deliver essential services at both local and regional scales. The combined occurrence of heat waves and droughts strongly affects ecosystem-atmosphere by reducing photosynthesis and plant vitality. Drought conditions also suppress leaf transpiration, diminishing the cooling potential of urban GI.

Atmospheric modelling offers valuable insights into the interactions between urban climate, green infrastructure, and human-perceived temperatures, and represents a crucial tool for predicting thermal stress in cities and urban parks, ultimately supporting the design of more climate-resilient urban environments. At the microscale, atmospheric models are integrated with in situ measurements of temperature radiation, and wind speed to improve predictions of human thermal stress during extreme heat events.  High-frequency Earth Observation data are essential for monitoring urban vegetation dynamics along the urban-rural gradient and during and after extreme climatic events. At the city scale, this work proposes a methodology to link spatio-temporal patterns of vegetation health, growth, and mortality to key abiotic stressors, enabling a more comprehensive assessment of GI functionality under challenging urban climatic conditions.

Durée
1 heure

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Salle Claude Froidevaux – E314, ENS, 24 rue Lhomond 75005, PARIS

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https://cnrs.zoom.us/j/93220842723?pwd=A5jqkXCdQlbYre7DuXMTn41w5J6b5k.1