General information

Reference

2025-3779  

Position description

Category

F11 Geotechnics - Engineer / Researcher

Job title

Post-doc Meta-Modeling of Rock Avalanche Hazards

Contract

Post-doctoral contrat

Contractual hours

Full-time

Contract duration

15 months

Context and contributions of the position

Joining the French Geological Survey (BRGM) means becoming part of France's leading public institution for Earth Science applications bringing together 1,000 wholeheartedly committed experts across 29 bases in Mainland and Overseas France.

BRGM focuses on enhancing geological knowledge and understanding of surface and sub-surface-related phenomena, with a view to meeting the challenges of environmental changes through innovative projects with societal implications.

Rock/ice avalanches are very fast gravitational flows (up to 100 km.hr-1) that can spread several kilometres away from the initiation area, and are thus a threat to population, buildings and infrastructures. The quantification of associated hazards includes the estimation of the avalanche propagation. Current methods to estimate propagation often rely on empirical approaches that allow to easily propagate uncertainties, but that relatively simplistic.

On the other hand, physically based numerical models better account for the complexity of processes. Over the past 20 years, thin-layer have met growing success for modelling gravitational flows.

Job description

However, they are associated to significant computing resources. Meta-modelling, which involves statistical approximations of the model trained from a database of simulations, offers a promising alternative to preserve the predictive capabilities of physically-based models while reducing computational costs, thus allowing for uncertainty propagation and hazard mapping.

The objective of this project is to adapt existing meta-modelling methods to thin-layer flow models, with an application to the risk of rock and/or ice avalanches in an alpine context, thus contributing to the assessment of emerging glacial and periglacial risks.

We propose to train a meta-model to estimate the results of SHALTOP, a thin-layer flow code developed at IPGP and used at BRGM, using the initial mass geometry and one or two rheological parameters as input. The post-doc will test at least two meta-modeling methods (e.g., Gaussian processes and PINNs, Physics-Informed Neural Networks) on a simple synthetic case (flow on an inclined plane) and on a real topography to reproduce a documented event in an alpine context. Advanced methods for adaptive sampling and dimension reduction will be used to improve the numerical efficiency of the meta-model training step while ensuring the accuracy of the estimated outputs. Particular attention will be paid to the ability of the meta-model to reproduce non-linear behaviours (e.g. overflows). The meta-model will then be used to construct a probabilistic impact map. The distributions of input parameters will be estimated either by expert judgment (e.g., for volume) and/or empirically (law derived from the literature or from calibration).


The numerical developments associated the project will be carried out on a github repository and distributed as a python package.
They will be presented, along with the application to a synthetic case and a real topography, in a scientific publication.

Profile

Requested start date : 01/09/2025
Education : Postdoctoral
Experience : 1 - 5 years

Expected knowledge: Proficiency in programming (Python/R), numerical modeling, and statistics is essential, along with a good practice of English (written and spoken).
Knowledge in hydraulic modeling, risk science, or meta-modeling will be appreciated, as well as a good level in French.

Desired skills: autonomy, rigor, analytical, writing and synthesis abilities.

Working conditions

You hold a doctoral degree obtained less than 3 years ago. The start date is envisaged for the last quarter of 2025. This post-doc will be based in the RMVT (Gravitational risks) unit of DRIS (Risks Direction) in Orléans.

Within an environment that promotes a healthy work/life balance, particularly thanks to remote working, BRGM prides itself on providing a friendly and caring place to work.

Awarded HRS4R certification in 2021, we are committed to supporting you throughout your career at BRGM. We provide you with a range of tools for developing your skills and expertise, with scope for career progression and geographic mobility.

At BRGM, you will gain from such benefits as a 13th month salary, days off compensating for unpaid overtime, a company canteen, sports facilities as well as holiday and leisure options.

At BRGM, you are guaranteed a transparent recruitment process. It is easy to apply! Please send us your application (up-to-date CV and cover letter) by 11/05/2025.

Because diversity matters to us at BRGM, all of our job vacancies are open to everyone!

We will examine your application as soon as the closing date has passed. If your application is short-listed, we will contact you for recruitment interviews during which you will have the opportunity to talk with the recruitment and HR departments as well as a cross-functional department.

Position location

Job location

France, Centre-Val de Loire, Loiret (45)

Location