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Detecting drawdowns masked by environmental stresses with water-level models.

Garcia CA, Halford KJ, Fenelon JM - Ground Water (2013)

Bottom Line: Pumping signals are generated with Theis models, where the pumping schedule is translated into water-level change with the Theis solution.This approach closely matched drawdowns simulated with a complex three-dimensional, hypothetical model and reasonably estimated drawdowns from an aquifer test conducted in a complex hydrogeologic system.Pumping-induced changes generated with a numerical model and analytical Theis model agreed (RMS as low as 0.007 m) in cases where pumping signals traveled more than 1 km across confining units and fault structures.

View Article: PubMed Central - PubMed

Affiliation: US Geological Survey, 2730 N Deer Run Rd, Carson City, NV 89701, USA.

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Cross section A-A′ (Figure 1), model grid, hydrogeologic framework, hydraulic-conductivity distribution, observation wells, and pumping well for hypothetical aquifer system. Colored areas represent aquifers and uncolored areas represent confining units.
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fig03: Cross section A-A′ (Figure 1), model grid, hydrogeologic framework, hydraulic-conductivity distribution, observation wells, and pumping well for hypothetical aquifer system. Colored areas represent aquifers and uncolored areas represent confining units.

Mentions: The reliability of differentiating environmental fluctuations and pumping responses with the drawdown estimation approach was tested with a numerically simulated hypothetical aquifer test, for which drawdowns were known because they were simulated. This hypothetical system was designed with some degree of hydrogeologic complexity. The hydrogeologic framework was conceptualized as layered sequences of hydrostratigraphic units that were offset vertically more than 500 m across a major fault (Figure 3). The fault was simulated as an interface where hydrostratigraphic units were juxtaposed; the fault was not assigned unique hydraulic properties. This hypothetical sequence is similar to the vertical distribution of units that were mapped in cross sections beneath Pahute Mesa (National Security Technologies, LLC 2010).


Detecting drawdowns masked by environmental stresses with water-level models.

Garcia CA, Halford KJ, Fenelon JM - Ground Water (2013)

Cross section A-A′ (Figure 1), model grid, hydrogeologic framework, hydraulic-conductivity distribution, observation wells, and pumping well for hypothetical aquifer system. Colored areas represent aquifers and uncolored areas represent confining units.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3675638&req=5

fig03: Cross section A-A′ (Figure 1), model grid, hydrogeologic framework, hydraulic-conductivity distribution, observation wells, and pumping well for hypothetical aquifer system. Colored areas represent aquifers and uncolored areas represent confining units.
Mentions: The reliability of differentiating environmental fluctuations and pumping responses with the drawdown estimation approach was tested with a numerically simulated hypothetical aquifer test, for which drawdowns were known because they were simulated. This hypothetical system was designed with some degree of hydrogeologic complexity. The hydrogeologic framework was conceptualized as layered sequences of hydrostratigraphic units that were offset vertically more than 500 m across a major fault (Figure 3). The fault was simulated as an interface where hydrostratigraphic units were juxtaposed; the fault was not assigned unique hydraulic properties. This hypothetical sequence is similar to the vertical distribution of units that were mapped in cross sections beneath Pahute Mesa (National Security Technologies, LLC 2010).

Bottom Line: Pumping signals are generated with Theis models, where the pumping schedule is translated into water-level change with the Theis solution.This approach closely matched drawdowns simulated with a complex three-dimensional, hypothetical model and reasonably estimated drawdowns from an aquifer test conducted in a complex hydrogeologic system.Pumping-induced changes generated with a numerical model and analytical Theis model agreed (RMS as low as 0.007 m) in cases where pumping signals traveled more than 1 km across confining units and fault structures.

View Article: PubMed Central - PubMed

Affiliation: US Geological Survey, 2730 N Deer Run Rd, Carson City, NV 89701, USA.

Show MeSH
Related in: MedlinePlus