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Reference : UMR3589-JEACAL-001
Workplace : TOULOUSE
Date of publication : Monday, March 29, 2021
Scientific Responsible name : Jean-Christophe Calvet
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 27 September 2021
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
Understanding and multi-scale modelling of shrinkage-swelling of clays (SSC) and of its financial impacts. Contributing elements to compensation schemes for natural disasters.
The objective of this PhD work is to develop new tools to estimate the claim cost related to the SSC phenomenon over France, building on a revised physical characterization of interactions between the atmosphere, the soil, and the built environement. This approach will be based on models and data belonging to the partners of this research project. In addition to a better characterisation of claim costs, this work will explore the future exposure to drought over France in the framework of climate warming. This work will also contribute to support SSC risk reduction public policies.
1 – Coupling existing models: i.e. the ISBA land surface model of Meteo-France and geotechnical models of BRGM, with local validation on instrumented sites. The ISBA model will be used to estimate soil moisture profiles from atmospheric variables. Suction profiles will be derived from the latter in order to calculater the geotechnical response to drought. This information will be locally spatialized.
2 – Validation at a regional scale: this local approach will be upscaled using the SSC claim costs data collected by CCR since 1989 as a benchmark.
3 – Spatialization over France: the aggregated SSC claim cost data will be used to assess the ISBA operational SSC monitoring chain of Meteo-France. The added value of a new version of the ISBA model, able to simulate leaf area index (LAI) and to assimilate satellite-derived LAI observations, will be assessed using the same protocol. The coupling with BRGM models will be evaluated, together with a data-driven approach based on the SSC claim costs data and soil-plant variables simulated by ISBA.
This PhD work will be performed in the VEGEO team of the mesoscale meteorology division of CNRM, Toulouse, France, in collaboration with CCR (Paris) and BRGM (Orléans).
Constraints and risks
The PhD work will imply the analysis of in situ and satellite observations and of model simulations. A good knowledge of land surface modelling is needed, together with skills in data processing and analysis, and in computer programming (Python, Fortran). Skills in written and oral communication are needed.
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