Mapping the city's trajectories to cool the city and better resist heat waves

Abstract. During the months of July and August 2021 and 2022, numerous climatic disturbances such as heat domes in Canada, floods and landslides in Belgium, Germany, Turkey, China as well as giant fires in Russia and Greece have marked the news and people’s minds. Climate inertia and the complexity of changing the world’s energy model make it necessary to adapt territories to limit the impacts of the changes that are underway. However, if the speeches on the urgency to act to cool the cities have become omnipresent, the implementations of solutions seem limited, and some territories even seem to be going in the opposite direction by massively artificializing the edges of urban areas. The objective of the FreshWay research project is to identify and analyse planning and implementation on the ground to combat summer heat waves and to represent the adaptation trajectories of cities. The first information that is questioned is the evolution of urban vegetation insofar as plants provide shade and allow cooling through the process of evapotranspiration. The paper presents the required information and the data model, cases study, the process to integrate data, the choice of indicators and the construction of trajectories from different perspectives for the municipality of Castelnau-le-lez, Sarcelles and Pontault-Combault, and at different level of details.