Melissa Poupelin is defending her thesis named : "Geoprospective and climate modelling of urban vegetation in a perspective of adaptation to heat waves: Dijon Métropole as a study case."

This work was conducted under the supervision of Thomas Thévenin and Yves Richard, with the guidance of Julien Pergaud, within the ThéMA laboratory (UMR CNRS 6049, UFC-uB) and the research team at the Climate Research Center of the Biogeosciences laboratory (UMR CNRS 6282, uB) in Dijon.

The defense will take place publicly on Monday, December 16th, at 2:00 PM, in the amphitheater of the Maison des Sciences de l'Homme at the University of Dijon (6, Esplanade Erasme, 21000, Dijon).  For those unable to attend in person, a link to join the defense via video conference will be shared a few days prior (the defense will be conducted in French).  The defense will be immediately followed by a celebratory reception, to which you are all warmly invited!

Jury composition

M. Vincent DUBREUIL - Professor, Laboratory LETG, CNRS, University Rennes 2, reviewer

M. Valéry MASSON - Director of Research, CNRS, CNRM & Météo-France, reviewer

Mme Julia HIDALGO - Director of Research, CNRS, laboratory LISST, University Toulouse Jean Jaurès, examiner

Mme Anne PUISSANT - Professor, laboratory LIVE, CNRS, Université de Strasbourg, examiner

M. Thomas THEVENIN - Professor, laboratory ThéMA, CNRS, University de Bourgogne, thesis supervisor

M. Yves RICHARD - Professor, laboratory Biogéosciences, CNRS, University de Bourgogne, thesis co-supervisor

M. Julien PERGAUD - Research Officer, CNRS, laboratory Biogéosciences, University de Bourgogne, co-advisor

Thesis Abstract

As a result of climate change, heat waves are increasing and intensifying. At the same time, more and more people live in cities where urban heat islands (UHI) are developing. Heat waves and combined UHI contribute to the emergence of health risks backed by thermal stress. France "discovered" this risk in 2003. Building on this experience, prevention policies have developed. But prevention is not enough and must be combined with policies to adapt to climate change. Town planning is to be re-examined. Choice of materials, colors, urban forms are to work. But, in terms of refreshment, the greatest potential lies in the greening of cities. The plants, by evapotranspiration, refresh the ambient air. Creating green spaces is favoring a cooling effect often called "Urban Freshness Island" (UFI). Faced with these challenges, urban planners are increasingly demanding tools to know where and how to plant vegetation at the metropolitan scale. It is therefore a question of having a systemic approach where one models the climate of the city by integrating the vegetated spaces and the scenarisation methods based on local needs. This approach is based on numerical modeling. With the SURFEX platform coupled to the MesoNH climate model developed by Météo France, we are first going to test the sensitivity of the model to a better description of urban vegetation. This first step assess the reference simulation. The application relates to Dijon Métropole which has a network of 72 temperature sensors essential for the validation of the control simulation of the model. The heat waves of 2020 demonstrated a drought that worsened during the summer that is an ideal study case to chel the impact of vegetation during heat waves at the city scale. The co-construction of green scenarios takes places into an european project called RESPONSE H2020 with Dijon's local urban planners. After this work step, we suggest integrated methods for calculating fine-scale revegetation scenarios. These scenarios can then be tested and compared to the reference simulation. Particular attention is paid to UTCI and ICU values ​​which make it possible to measure the impact of adding vegetation on temperatures at street scale.