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| Titel |
Delineation of geologic facies in heterogeneous aquifers by the Truncated Plurigaussian Method |
| VerfasserIn |
Raul Perulero Serrano, Monica Riva, Alberto Guadagnini |
| 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 |
250046850
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| Zusammenfassung |
| We provide a geostatistically-based reconstruction of the spatial distribution of the main
litho-facies characterizing the geological makeup of the groundwater system contributing to
the major natural springs in the area of Cremona, Italy. Over-exploitation of the groundwater
system for agricultural and industrial uses in the study area can result in significant
lowering of the water table, thus threatening the environmental conditions favored by
the natural springs in the area under study. The groundwater system is constituted
by two main productive aquifers, which are separated by a locally discontinuous
aquitard. We start from an existing data-base comprising detailed sedimentological
information as well as data on time-evolution of groundwater levels in the two major
aquifers. A set of (conditional) three-dimensional lithofacies distributions within the
system is simulated in a Monte Carlo framework estimated by means of (a) an
indicator-based approach and (b) the Truncated Plurigaussian method. While the former
methodology only relies on a variogram-based analysis, the latter allows integrating
geological concepts, e.g., relative locations and proportions of the different lithofacies, in
the simulation procedure. As such, the truncated plurigaussian simulation method
provides a way of using both local/regional and conceptual geological information
(from various sources) to infer the distributions of geo-materials and, ultimately, the
associated hydraulic parameters. It retains the main advantages of the truncated Gaussian
method, in the sense that it produces permissible sets of indicator semi-variograms
and cross-semi-variograms, and overcomes some of its limitations, most notably
the fact that the truncated Gaussian method only reproduces sequentially ranked
categories. The resulting aquifer reconstructions are then adopted to provide multiple
realizations of the groundwater flow field to assess the impact that various scenarios
involving groundwater extraction from the system have on the water availability to the
springs.
Acknowledgements Financial support by Marie Curie Initial Training Networks Towards
Improved Groundwater Vulnerability Assessment (IMVUL) is gratefully acknowledged. |
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