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| Titel |
Fine scale 3D integrated study of fluvio-glacial sediments |
| VerfasserIn |
Lorenzo Pessina, Fulvia Baratelli, Riccardo Bersezio, Laura Cattaneo, Emmanuele Cavalli, Fabrizio Felletti, Mauro Giudici, Mauro Mele, Chiara Vassena |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250050722
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| Zusammenfassung |
| The continuous improvement of numerical tools to simulate the heterogeneity distribution,
water flow and contaminant transport in porous fluvio-glacial sediments permits to handle 3D
fine fields at fine scales. The assessment of the reliability of geostatistical, flow and transport
simulation methods when applied to practical applications requires a large set of data. Here
we show the work in progress on a study which integrates different expertise in geosciences.
The block (approximately 7 m à 4 m à 1.5 m) was dug into a gravel and sand unit
of the Late Pleistocene sandur of the Verbano glacier. The following data were
collected: sedimentological logs, photomosaics and facies maps at cm-scale accuracy,
along vertical and horizontal intersecting planes, with a maximum spacing of 1 m;
geoelectrical and GPR surveys on the top of the block; infiltration tests at several positions,
with a spacing of about 50 cm; grain-size distribution measurements on samples;
estimates and measurements of hydraulic conductivity on samples of the sandy gravel,
sand and silty sand facies to work out an hydrofacies classification from the facies
association. The 3D simulation of the block heterogeneity was obtained with Sequential
Indicator simulations (SISIM), conditioned on the hydrofacies maps after GIS aided
modeling of the major stratigraphic boundary: the simulated 3D image represents
a map of the distribution of the K values assigned to each hydrofacies, and was
used to compute equivalent K and dispersion coefficient, D. The future objective
of the work is to conduct several numerical tests to quantify the reliability of the
stochastic simulations, the ability of geophysical techniques to improve the subsurface
reconstruction, the link between different connectivity indicators and equivalent K and D. |
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