Electrical resistivity—hydraulic conductivity relationships in glacial outwash aquifers

Abstract

Empirical field relationships between the apparent formation factors from surface resistivity soundings and hydraulic conductivity from pumping tests in fresh water granular aquifers usually show positive correlations. These relationships can be adequately explained by theory if consideration is taken of in situ field conditions. A sound theoretical basis for relating apparent formation factor to pertinent hydrogeophysical parameters in homogeneous isotropic sand is a three‐phase parallel resistor model which explicity includes parameters of porewater resistivity, grain size and shape, porosity, tortuosity, and intergranular surface conductance. The veracity of the theoretical model is supported by data from laboratory tests. The model demonstrates that intergranular surface conductance is an important factor at small grain sizes and high porewater resistivities, operating to lower the apparent formation factor. The model further shows that direct relationships between hydraulic conductivity and formation factor are weak in the normal range of porewater resistivity, being strongly dependent on porosity. When systematic variation of in situ porosity and aquifer layering effects are considered, a simulated field curve relating the apparent formation factor to hydraulic conductivity is shown to compare favorably with the comparable curve from field data for thirteen pumping test sites in southern Rhode Island. Both theoretical and empirical results demonstrate a useful positive correlation between aquifer apparent formation factor and hydraulic conductivity. Quantitative interpretation, however, is imprecise because of nonuniqueness of interpretation and inherent variation in important aquifer parameters, especially porosity.

A Relationship between Hydraulic Conductivity and Electrical Properties of Silty Sand on the Riverside of the Nakdong River

“…(1) (Kelly, 1977;Heigold et al, 1979;Urish, 1981; K 343.84τ 0.00094 -= Kosinski and Kelly, 1981;Ponzini et al, 1983;Allessandrello and Lemoine, 1983;Frohlich et al, 1996). …”

Influence of Degree of Saturation in the Electric Resistivity–Hydraulic Conductivity Relationship

“…Some previous studies combine two or more regimes such that, D.W. Urish (1981), where, theoretically three-phase parallel resistor model, supported by data from laboratory tests assumed inverse correlation between porosity and hydraulic conductivity. From empirical and theoretical model a positive correlation between apparent formation factor and hydraulic conductivity is shown.…”

“…The apparent formation factor (F a ) then approaches the intrinsic formation factor (Fi), which is the case for saline pore-water. But for high-resistivity fresh water sands, the surface conductance effect represented by the term (Urish, 1981).…”

“…The mathematical characteristics of this sample classify it in the third category of our analytical models (Fig.5-B), where porosity is higher than 50%, higher than water saturation. The category highlights on the effect of low saturation on the relation between hydraulic conductivity and resistivity of porous media, where in low saturation conductivity of the electrical double layer increases, and surface conductance becomes the main transport mechanism (Pfannkuch, 1969, Urish, 1981, Brovelli, et al, 2005. The data of Mt.…”

Characterizing hydrogeologic heterogeneity using lithologic data

“…Methods employed in the petroleum industry for relating intrinsic permeability to borehole geophysical data are described in Lake and Carroll (1986) and Flint andBryant (1993): Lahm et al (1995) recently reviewed several efforts to relate permeability to borehole geophysical data including Timur (1968), Croft (1971, Keys and MacCary (1971), Kelly (1977), Biella et al (1983), 5 Doveton (1986), Wendt et al (1986), Urish (1981), and Jorgensen (1989 (Thayer et al, 1994). Note that the interpolation process has preserved horizontal stratification of the sediments.…”