PhD title : «Return period modeling of extreme surface rainfall in a mediterranean mountainous region (Cévennes-Vivarais) »
Description: This thesis focuses on the rainfall risk in the Cévennes-Vivarais region, a French Mediterranean region which regularly undergoes rapid and localized floods, called flash floods. A statistical measure of risk is the frequency of occurrence or equivalently the return period. Since rain events accumulate over time, these statistics are usually estimated for rainfall intensities aggregated over periods ranging from the resolution of the measurement (5 minutes, 1 hour) to the duration of the rainfall event (several tens of hours to several days) via a set of curves called IDF (Intensity-Duration-Frequency) curves. However hydrologic routing induces that the areal accumulation of rain weights actually as much as its temporal accumulation. Yet this notion of surface is little present in the literature of risk analysis. The challenge of this thesis is to propose an integrated statistical approach for estimating surface risk in Cévennes-Vivarais, i.e. for computing regional Intensity-Duration-Area-Frequency (rIDAF) curves. The originality of the proposed model will be to combine advanced statistical tools with physical (hydrometeorological) modelling. More precisely a model of rainfall spatial invariance will be jointly used with a model of temporal invariance within a statistical Bayesian framework, in order to better understand the multi-scale processes producing heavy rainfalls in Cévennes-Vivarais.
Application: Applicants must hold a Master’s degree (or equivalent) in statistics or geosciences. A strong background in statistics or quantitative methods is required, as well as strong skills in scientific programming (R/matlab). An interest for hydrometeorological applications is essential and a good general knowledge of earth sciences is desirable. Fluency in English is required.
Expressions of interest should be sent together with a short CV, a cover letter and Master transcript to Dr Juliette Blanchet, firstname.lastname@example.org.