10 Sep 2019

Seminar: Stochastic Modeling of the Earth Subsurface: Dealing with Unobserved Natural Systems


Many hydrological processes taking place at the Earth’s surface are directly observable, either through

in-situ measurements or by using remote sensing techniques. In contrast, understanding properties of the

subsurface poses formidable observational challenges. Firstly, measurements of the Earth’s interior are

either difficult and expensive to acquire (e.g., boreholes) or indirect (e.g., measurement of subsurface flow

and tracer concentrations). Secondly, the Earth’s interior is 3-dimensional, resulting in very empty data

spaces. For example, even intensive drilling campaigns and geophysical surveys of an aquifer often sample

only a small fraction of the total rock volume.

This talk will present stochastic aquifer modeling approaches that allow quantifying uncertainty in such

data-poor problems. For many practical questions, the uncertainty in subsurface hydraulic properties further

propagates into uncertainty in water resources management problems—for example, the transport of

contaminant to a drinking water well, the intake of a groundwater-based desalination plant, or the behavior

of a tracer in a subglacial drainage system. Stochastic aquifer models allow using a statistical description

of the unobserved system to formulate ensemble predictions, resulting in a distribution of possible outcomes.

The use of stochastic models will be illustrated in different environments, focusing on applications that

integrate indirect data through inverse approaches.

Grégoire Mariéthoz’s research and teaching areas revolve around geostatistics, image processing, data analysis

methods and their application to earth observation, remote sensing, hydro(geo)logy and inverse problems. He is

currently the Adjunct Director and Professor at the Institute of Earth Surface Dynamics, University of Lausanne,

Switzerland. Mariéthoz is also the Director of the Swiss Geocomputing Centre.


  • Adjunct Director and Professor at the Institute of Earth Surface Dynamics, University of Lausanne, Switzerland and Director of the Swiss Geocomputing Centre

    Dr. Grégoire Mariéthoz

    Social Links

Share This Event