Thèse Diversification des Paysages Agricoles et Résilience Hydrique des Agroécosystèmes Apport de la Télédétection Optique et Thermique H/F Doctorat.Gouv.Fr

Établissement : Université de Toulouse École doctorale : SDU2E - Sciences de l'Univers, de l'Environnement et de l'Espace Laboratoire de recherche : CESBIO - Centre d'Etudes Spatiales de la BIOsphère Direction de la thèse : Gilles BOULET ORCID 0000000239057560 Début de la thèse : 2027-09-01 Date limite de candidature : 2026-11-23T23:59:59 Les systèmes agricoles sont confrontés à une pression croissante sur les ressources en eau en raison de l'augmentation de la fréquence et de l'intensité des épisodes de sécheresse. Dans ce contexte, les pratiques agroécologiques et la diversification des paysages agricoles sont considérées comme des leviers susceptibles d'améliorer la régulation des flux d'eau, de limiter le stress hydrique des cultures et de renforcer la capacité d'adaptation des agroécosystèmes.
Toutefois, les effets de la diversification paysagère restent encore insuffisamment caractérisés et quantifiés à l'échelle du territoire. La plupart des études se concentrent sur la parcelle ou l'exploitation agricole alors que de nombreux processus hydrologiques dépendent d'interactions entre les différentes composantes du paysage.
L'émergence de nouvelles générations de données d'observation de la Terre, notamment Sentinel 2 et la future mission thermique TRISHNA, offre aujourd'hui des perspectives inédites pour analyser les relations entre structure paysagère, fonctionnement hydrique et résilience des agroécosystèmes. La thèse visera à développer une approche intégrée combinant observations satellitaires, données de terrain et modélisation hydrologique afin de mieux comprendre le rôle de la diversification des paysages dans la régulation de l'eau à différentes échelles spatiales. The PhD will be jointly supervised by the French and Tunisian supervisors through regular scientific meetings and remote exchanges. Progress meetings will be organized to monitor the different stages of the research, from data acquisition and structuring to analysis, modelling and dissemination of results.
The first year will mainly focus on the literature review, characterization of the two study territories and field campaigns in France and Tunisia. The second and third years will mainly focus on data analysis, modelling, interpretation of results and preparation of scientific publications and the PhD manuscript.
The PhD will be conducted through a co-supervision between the University of Toulouse and the University of Carthage - National Agronomic Institute of Tunisia (INAT). It will benefit from complementary expertise in remote sensing, hydrology, water and energy transfer modelling, spatial analysis of agricultural landscapes and agroecology.
France
- Gilles Boulet - PhD Supervisor, University of Toulouse - UMR CESBIO
Thermal and optical remote sensing, evapotranspiration, water stress, water and energy transfer modelling, TRISHNA mission.
- Sameh Saadi - Co-supervisor, University of Toulouse - École d'Ingénieurs de PURPAN / UMR DYNAFOR
Remote sensing applied to agroecosystems, water and energy balance modelling, spatialized evapotranspiration estimation and crop water stress analysis.
An application for authorization to co-supervise a PhD will be submitted shortly to the SEVAB Doctoral School.
Tunisia
- Zeineb Kassouk - Co-supervisor, University of Carthage - National Agronomic Institute of Tunisia
Remote sensing and GIS, spatial and temporal analysis of agricultural landscapes, remote sensing data processing and agricultural dynamics monitoring.
- Mehdi Ben Mimoun - Co-supervisor, University of Carthage - National Agronomic Institute of Tunisia
Agroecology and agricultural systems, diversification of production systems, climate change adaptation, agroecosystem resilience and agricultural transition pathways.
Objective 1: Characterize the structure, diversity and evolution of agricultural landscapes
This objective aims to map land cover and cropping systems, characterize the structure and heterogeneity of agricultural landscapes, identify diversification gradients and major agroecological practices, analyse their spatial and temporal evolution, and characterize the role of semi-natural elements such as hedgerows, grass strips and agroforestry systems.
Objective 2: Characterize and spatialize the hydrological functioning of agroecosystems
This objective will combine Sentinel-2 time series, thermal observations from TRISHNA when available, meteorological and soil data, field observations collected at the French and Tunisian study sites, and fine-scale spatialized water and energy balance models.
The objective is to characterize and spatialize evapotranspiration, soil water status and crop water stress in order to better understand their variability in relation to field characteristics and surrounding landscape structure.
Objective 3: Analyse the relationships between landscape diversification and water resilience across spatial scales
This objective will determine which landscape configurations and agroecological practices are associated with improved water regulation, to what extent crop diversity, rotations, intercropping and semi-natural elements contribute to reducing water stress, how these effects vary according to pedoclimatic conditions, and to what extent effects observed at the field scale can translate to the landscape and watershed scales