1. Geostatistical investigations for suitable mapping of the water table: the Bordeaux case (France).
- Author
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Guekie simo, Aubin, Marache, Antoine, Lastennet, Roland, and Breysse, Denys
- Subjects
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WATER table , *GEOLOGICAL statistics , *GEOLOGICAL mapping , *COKRIGING , *GROUNDWATER flow - Abstract
Methodologies have been developed to establish realistic water-table maps using geostatistical methods: ordinary kriging (OK), cokriging (CoK), collocated cokriging (CoCoK), and kriging with external drift (KED). In fact, in a hilly terrain, when piezometric data are sparsely distributed over large areas, the water-table maps obtained by these methods provide exact water levels at monitoring wells but fail to represent the groundwater flow system, manifested through an interpolated water table above the topography. A methodology is developed in order to rebuild water-table maps for urban areas at the city scale. The interpolation methodology is presented and applied in a case study where water levels are monitored at a set of 47 points for a part urban domain covering 25.6 km close to Bordeaux city, France. To select the best method, a geographic information system was used to visualize surfaces reconstructed with each method. A cross-validation was carried out to evaluate the predictive performances of each kriging method. KED proves to be the most accurate and yields a better description of the local fluctuations induced by the topography (natural occurrence of ridges and valleys). [ABSTRACT FROM AUTHOR]
- Published
- 2016
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