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Seminar Sponsored by:Water Resources Research Center and ‘Ike Wai

University of Hawai‘i at Manoa

Tuesday, September 10, 2019 | Noon | IT 105AInformation Technology Center, 2520 Correa RD

Fall 2019 Seminar SeriesALL WELCOME! (Lunch available, first comefirst served; please bring your own beverage).

For more information contact:Leah Bremerlbremer@hawaii.edu808-956-7938

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

Dr. Grégoire Mariéthoz

Many hydrological processes taking place at the Earth’s surface are directly observable, either throughin-situ measurements or by using remote sensing techniques. In contrast, understanding properties of thesubsurface poses formidable observational challenges. Firstly, measurements of the Earth’s interior areeither difficult and expensive to acquire (e.g., boreholes) or indirect (e.g., measurement of subsurface flowand tracer concentrations). Secondly, the Earth’s interior is 3-dimensional, resulting in very empty dataspaces. For example, even intensive drilling campaigns and geophysical surveys of an aquifer often sampleonly a small fraction of the total rock volume.

This talk will present stochastic aquifer modeling approaches that allow quantifying uncertainty in suchdata-poor problems. For many practical questions, the uncertainty in subsurface hydraulic properties furtherpropagates into uncertainty in water resources management problems—for example, the transport ofcontaminant to a drinking water well, the intake of a groundwater-based desalination plant, or the behaviorof a tracer in a subglacial drainage system. Stochastic aquifer models allow using a statistical descriptionof 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 thatintegrate indirect data through inverse approaches.

Grégoire Mariéthoz’s research and teaching areas revolve around geostatistics, image processing, data analysismethods and their application to earth observation, remote sensing, hydro(geo)logy and inverse problems. He iscurrently 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.

H a w a i ‘ iWRRCUniversity of Hawai‘i at Manoa-University of Hawai‘i at Manoa

InformatonTechnologyCenter

Seminar Location

Note: Seminar attendees,please inform the front deskthat you will be attending theWRRC/‘Ike Wai seminar.