Two years after the beginning of the Enigma ITN project, four workshops were organized and all ESRs participated to the 4th Enigma Cargèse Summer School in Cargèse, 25 June – 7 July 2018, where they presented a poster.
All the dissemination documents (presentations and posters) of the ESRs are available on their personal webpages on the Enigma website :
https://enigma-itn.eu/people/research-fellows/(s’ouvre dans une nouvelle fenêtre)Some details about the work performed:
WP2: Explore coupled dynamic processes in targeted highly instrumented sites
• Scientific objective 2: explore in-situ flow, transport and reaction processes to address current open scientific questions based on highly instrumented experimental sites where the new results, data and open source codes
- ESR1 did numerical modelling on the impact of heterogeneity and connectivity on mixing and reactions in coastal aquifers
- ESR2 carried out high resolution time-series analysis of ground water levels and different tracer tests in the riparian aquifer of the Selke River
- ESR3 : three in-stream piezometers were installed in the Emme site for dissolved gas relative concentrations analysis.
- ESR4 completed two experiments at the SKB Äspö tunnel Hard Rock Laboratory.
• Technological objective 2: transfer the obtained knowledge of process dynamics in heterogeneous porous and fractured media to operational models for predicting the evolution of subsurface environments.
- ESR2 worked on a numerical flow model in HGS.
- ESR3 learnt how to use: HydroGeoSphere and OpenFOAM (CFD code) multi-phase solvers interFoam (IF).
- ESR4 created a 3D statistical Discrete Fracture Network (DFN).
WP3: Quantify temporal changes in subsurface water content and fluxes distributions
● Scientific objective 1: design novel in situ experimental strategies for quantifying subsurface process dynamics by coupling innovative experimental methods and inverse modelling approaches
- ESR5 tested rock physic models to infer their ability to describe VP and Vs seismic data acquired during experiments at Ploemeur hydrogeological observatory.
- ESR6 developed a new model to describe temperature profile in boreholes, dedicated to the high resolution measurement ability of Distributed Temperature Sensing (DTS) data.
- ESR7 monitored thermal dynamics in the subsurface using fiber optic distributed temperature (FO-DTS) sensing and thermal infrared (TIR) images from drone flights for the top part of the media and temperature profiling in boreholes for the groundwater temperature.
- ESR8 carried out monthly vertical gravity gradient survey with a relative gravimeter out at the geodetic observatory in Karstic environment on the Larzac Plateau, France.
●Technological objective 1: develop and validate innovative environmental sensing techniques with the required sensitivity, as well as spatial and temporal resolution to monitor dynamic processes
- ESR5 designed and carried out a controlled infiltration experiment using injected water and geophysical measurements at the Ploemeur site in France.
- ESR6 designed a framework for real time flow profiling in a wellbore using DTS temperature data to analyze fracture.
- ESR7 used combination of FO-DTS and TIR imaging for the upper part of the media in combination with the profiling in boreholes to have insights on the groundwater upwelling processes occurring on land.
- ESR8 developed survey protocols to monitor vertical gravity gradients for hydrological signal detection. The development and coupling of a hydrological model for the site with a gravity forward routine has been conducted for joint analysis. The operability and sensitivity at the level of 10nm.s−2 have been shown by Muquans in a publication this year (Ménoret et al., 2018).
WP4: Create new methods for tracking the transport and reactivity of chemical species in subsurface
•Scientific objective 1:
- ESR9 : Electrical Resistivity Tomography (ERT) :The relationship between the conductive phase distribution and the effective electrical conductivity is being investigated both theoretically and experimentally for a simple case of a 2-D layered medium.
- ESR10 carried out numerical study of time-lapse GPR full-waveform inversion to detect tracer plumes. GPR-FWI was tested for its potential to detect tracer plumes and to better plan the experimental setup. Detailed hydrogeological model was generated based on past measurements.
- ESR11 explored the roles of parameter uncertainty and spatial heterogeneity using Monte-Carlo simulations.
- ESR12 performed a soil column experiment with induced calcite precipitation in collaboration with Yuxin Wu of the Lawrence Berkeley National Laboratory in the United States.
•Technological objective 1:
- ESR9 performed conservative fluorescent tracer tests in the laboratory using the coupling of a 2-D millifluidic setup equipped with a fluorimetric setup, and a geoelectrical monitoring setup
- ESR11: An innovative multi tracer experiment using jointly a dye tracer, heat and a dissolved gas cocktail, (He-Xe) was performed in a chalk aquifer nearby Mons, Belgium.
- ESR12 developed a novel laboratory setup combining a millifluidic-cell and an SIP measurement system to quantitatively investigate SIP response and biochemical reactions.
WP5: Design inverse modelling strategies for dynamic processes in complex subsurface structures
•Scientific objective 1:
- ESR13 developed a modeling and inversion framework for monitoring solute tracer tests with the help of geoelectrical monitoring. Field experiments were conducted at the hydrogeological test site Lauswiesen.
- ESR14 conducted time-lapse cross-hole electrical resistivity tomography (CHERT) in the Argentona experimental site. The experiment captured short-term and long-term salinization events in the coastal aquifer.
- ESR15 proposed a probabilistic inversion framework to integrate realistic prior information on structure. A paper entitled “Updating structural uncertainty using features of geophysical data” is in preparation.
•Technological objective 2:
- ESR15 explored Bayesian evidential learning (BEL) as a method to integrate flow and transport simulations and geophysical forward models.
