The Application of Spectral Induced Polarization to Determination of Hydraulic Conductivity

Mapping Intimacies ◽

10.26686/wgtn.17013986 ◽

2021 ◽

Author(s):

◽

Sheen Joseph

Keyword(s):

Grain Size ◽

Relaxation Time ◽

New Zealand ◽

Hydraulic Conductivity ◽

Time Constant ◽

Coastal Aquifers ◽

Induced Polarization ◽

Pore Fluid ◽

Relaxation Time Constant ◽

Spectral Induced Polarization

<p>Spectral Induced Polarization (SIP) is a geophysical technique that measures the frequency dependence of the electrical conductivity of a material. This thesis is an attempt to investigate the potential of using SIP as a proxy to predict the hydraulic conductivity of New Zealand shallow coastal aquifers. SIP measurements were made on sand samples that are typical of New Zealand coastal aquifers with a custom built impedance spectrometer and sample holder allowing the measurement of a phase difference as small a milliradian. Even though the relaxation time shows a small dependence on pore fluid conductivity, especially at lower pore fluid conductivities, this variation is not serious enough to affect the hydraulic conductivity estimation at the field scale, but could be significant in the investigation of mechanisms that cause polarization in porous media. Measurements on sieved fractions of sand established that there is an excellent correlation between the Cole-Cole relaxation time constant and grain size. The Cole-Cole relaxation time constant is very sensitive to the grain size distribution. Hydraulic conductivity predictions were attempted using various existing models. While the results are encouraging, it looks like there may not be a single universal model to predict hydraulic conductivity using SIP response. When a correction term in the form of a multiplication constant is used, all the tested models seem to make very good predictions. But the constants calculated by fitting to the measured data could be applicable only to the type of materials studied. The dependence of the existing models on quantities like counterion diffusion coefficient, electrical formation factor and porosity makes hydraulic conductivity prediction challenging as these quantities are difficult to measure accurately in a field setting. Nevertheless it is concluded that SIP can be successfully applied to study hydraulic conductivity of New Zealand shallow coastal aquifers.</p>

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The Application of Spectral Induced Polarization to Determination of Hydraulic Conductivity

10.26686/wgtn.17013986.v1 ◽

2021 ◽

Author(s):

◽

Sheen Joseph

Keyword(s):

Grain Size ◽

Relaxation Time ◽

New Zealand ◽

Hydraulic Conductivity ◽

Time Constant ◽

Coastal Aquifers ◽

Induced Polarization ◽

Pore Fluid ◽

Relaxation Time Constant ◽

Spectral Induced Polarization

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Effects of salinity and pH on the spectral induced polarization signals of graphite particles

Geophysical Journal International ◽

10.1093/gji/ggaa087 ◽

2020 ◽

Vol 221 (3) ◽

pp. 1532-1541

Author(s):

Yuxin Wu ◽

Luca Peruzzo

Keyword(s):

Relaxation Time ◽

Time Constant ◽

Negative Impact ◽

Positive Impact ◽

Electronic Conductivity ◽

Induced Polarization ◽

Graphite Inclusion ◽

Relaxation Time Constant ◽

Graphite Particles ◽

Spectral Induced Polarization

SUMMARY The electrical property of micrometre-sized graphite particles was investigated under different particle concentration, particle size, fluid conductivity and pH conditions. Due to its large internal electronic conductivity and ability to polarize under external potential field, significant enhancement of its spectral induced polarization (SIP) responses is observed when graphite is included in sand mixtures. While a small amount of graphite inclusion significantly increases the SIP response of its mixtures with sand, further concentration increase does not necessarily lead to a proportional increase of the SIP response. This is shown to be related to the formation of graphite aggregates at higher concentrations. Changes of fluid salinity have a significant effect on graphite's SIP behaviour. This includes a positive impact on normalized chargeability and imaginary conductivity, but a negative impact on chargeability and relaxation time constant. The effect of pH on the SIP response of graphite is small but shows consistent trend, where pH increase leads to a decrease of both the chargeability and relaxation time constant. The underlying cause of this effect is not clear.

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Impact of controlled changes in grain size and pore space characteristics on the hydraulic conductivity and spectral induced polarization response of "proxies" of saturated alluvial sediments

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-7-6057-2010 ◽

2010 ◽

Vol 7 (4) ◽

pp. 6057-6080 ◽

Cited By ~ 5

Author(s):

K. Koch ◽

A. Kemna ◽

J. Irving ◽

K. Holliger

Keyword(s):

Grain Size ◽

Hydraulic Conductivity ◽

Pore Space ◽

Groundwater Resources ◽

Fine Sand ◽

Induced Polarization ◽

Alluvial Deposits ◽

Spectral Induced Polarization ◽

Industrial Grade ◽

Granulometric Characteristics

Abstract. Understanding the influence of pore space characteristics on the hydraulic conductivity and spectral induced polarization (SIP) response is critical for establishing relationships between the electrical and hydrological properties of surficial unconsolidated sedimentary deposits, which host the bulk of the world's readily accessible groundwater resources. Here, we present the results of laboratory SIP measurements on industrial-grade, saturated quartz samples with granulometric characteristics ranging from fine sand to fine gravel, which can be regarded as proxies for widespread alluvial deposits. We altered the pore space characteristics by changing (i) the grain size spectra, (ii) the degree of compaction, and (iii) the level of sorting. We then examined how these changes affect the SIP response, the hydraulic conductivity, and the specific surface area of the considered samples. In general, the results indicate a clear connection between the SIP response and the granulometric as well as pore space characteristics. In particular, we observe a systematic correlation between the hydraulic conductivity and the relaxation time of the Cole-Cole model describing the observed SIP effect for the entire range of considered grain sizes. The results do, however, also indicate that the detailed nature of these relations depends strongly on variations in the pore space characteristics, such as, for example, the degree of compaction. The results of this study underline the complexity of the origin of the SIP signal as well as the difficulty to relate it to a single structural factor of a studied sample, and hence raise some fundamental questions with regard to the practical use of SIP measurements as site- and/or sample-independent predictors of the hydraulic conductivity.

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Controlled changes in grain size and pore characteristics and their impact on the hydraulic conductivity and spectral induced polarization response of proxies of alluvial sediments

10.1190/1.3255103 ◽

2009 ◽

Author(s):

Kristof Koch ◽

James Irving ◽

Klaus Holliger ◽

Andreas Kemna

Keyword(s):

Grain Size ◽

Hydraulic Conductivity ◽

Induced Polarization ◽

Pore Characteristics ◽

Alluvial Sediments ◽

Spectral Induced Polarization ◽

Polarization Response

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Spectral induced polarization measurements for predicting the hydraulic conductivity in sandy aquifers

Hydrology and Earth System Sciences ◽

10.5194/hess-17-4079-2013 ◽

2013 ◽

Vol 17 (10) ◽

pp. 4079-4094 ◽

Cited By ~ 30

Author(s):

M. Attwa ◽

T. Günther

Keyword(s):

Relaxation Time ◽

Hydraulic Conductivity ◽

Empirical Relationship ◽

Weighted Average ◽

Induced Polarization ◽

Suggested Approach ◽

Spectral Induced Polarization ◽

Groundwater Aquifer ◽

Least Squares Fit ◽

Sandy Aquifers

Abstract. Field and laboratory spectral induced polarization (SIP) measurements are integrated to characterize the hydrogeological conditions at the Schillerslage test site in Germany. The phase images are capable of monitoring thin peat layers within the sandy aquifers. However, the field results show limitations of decreasing resolution with depth. In comparison with the field inversion results, the SIP laboratory measurements show a certain shift in SIP response due to different compaction and sorting of the samples. The SIP data are analyzed to derive an empirical relationship for predicting the hydraulic conductivity (K). In particular, two significant but weak correlations between individual real resistivities (ρ') and relaxation times (τ), based on a Debye decomposition (DD) model, with measured K are found for the upper groundwater aquifer. The maximum relaxation time (τmax) and logarithmically weighted average relaxation time (τlw) show a better relation with K values than the median value τ50. A combined power law relation between individual ρ' and τ with K is developed with an expression of A · (ρ')B · (τlw)C, where A, B and C are determined using a least-squares fit between the measured and predicted K. The suggested approach with the calculated coefficients of the first aquifer is applied for the second. Results show good correlation with the measured K indicating that the derived relationship is superior to single phase angle models as Börner or Slater models.

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Spectral induced polarization measurements for environmental purposes and predicting the hydraulic conductivity in sandy aquifers

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-10-5315-2013 ◽

2013 ◽

Vol 10 (4) ◽

pp. 5315-5354 ◽

Cited By ~ 2

Author(s):

M. Attwa ◽

T. Günther

Keyword(s):

Relaxation Time ◽

Hydraulic Conductivity ◽

Empirical Relationship ◽

Induced Polarization ◽

Suggested Approach ◽

Polarization Measurements ◽

Spectral Induced Polarization ◽

Groundwater Aquifer ◽

Least Squares Fit ◽

Sandy Aquifers

Abstract. Low-frequency field and laboratory induced polarization measurements are carried out to characterize the hydrogeological conditions at Schillerslage test site in Germany. The laboratory spectral induced polarization (SIP) data are analyzed to derive an empirical relationship for predicting the hydraulic conductivity (K) in the field scale. On the other hand, the results from SIP sounding and profiling field data indicate that the method identifies the lithological layers with sufficient resolution to achieve our objectives. Two main Quaternary groundwater aquifers separated by a till layer can be well differentiated. Furthermore, the phase images are also capable of monitoring thin peat layers within the sandy groundwater aquifer. However, the field results show limitations of decreasing resolution with depth and/or low data coverage. Similarly, the SIP laboratory results show a certain shift in SIP response due to different compaction and sorting of the samples. The overall results obtained show that the integration of field and laboratory SIP measurements is an efficient tool to avoid a hydrogeological misinterpretation. In particular, two significant but weak correlations between individual real resistivities (ρ') and relaxation times (τ), based on a Debye decomposition (DD) model, with measured K are found for the upper groundwater aquifer. While the maximum relaxation time (τmax) and logarithmically weighted average relaxation time (τlw) show a better relation with K values than the median value τ50, however, the single relationships are weak. A combined power law relation between individual ρ' and/or τ with K is developed with an expression of A · (ρ')B · (τlw)C, where A, B and C are determined using a least-squares fit between the measured and predicted K. The suggested approach with the calculated coefficients of the first aquifer is applied for the second one. The results indicate a good correlation with the measured K and prove to be superior to single phase angle models as the Börner or Slater models.

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Impact of changes in grain size and pore space on the hydraulic conductivity and spectral induced polarization response of sand

Hydrology and Earth System Sciences ◽

10.5194/hess-15-1785-2011 ◽

2011 ◽

Vol 15 (6) ◽

pp. 1785-1794 ◽

Cited By ~ 40

Author(s):

K. Koch ◽

A. Kemna ◽

J. Irving ◽

K. Holliger

Keyword(s):

Grain Size ◽

Hydraulic Conductivity ◽

Pore Space ◽

Groundwater Resources ◽

Fine Sand ◽

Induced Polarization ◽

Spectral Induced Polarization ◽

Industrial Grade ◽

Granulometric Characteristics ◽

Cole Model

Abstract. Understanding the influence of pore space characteristics on the hydraulic conductivity and spectral induced polarization (SIP) response is critical for establishing relationships between the electrical and hydrological properties of surficial unconsolidated sedimentary deposits, which host the bulk of the world's readily accessible groundwater resources. Here, we present the results of laboratory SIP measurements on industrial-grade, saturated quartz samples with granulometric characteristics ranging from fine sand to fine gravel. We altered the pore space characteristics by changing (i) the grain size spectra, (ii) the degree of compaction, and (iii) the level of sorting. We then examined how these changes affect the SIP response, the hydraulic conductivity, and the specific surface area of the considered samples. In general, the results indicate a clear connection between the SIP response and the granulometric as well as pore space characteristics. In particular, we observe a systematic correlation between the hydraulic conductivity and the relaxation time of the Cole-Cole model describing the observed SIP effect for the entire range of considered grain sizes. The results do, however, also indicate that the detailed nature of these relations depends strongly on variations in the pore space characteristics, such as, for example, the degree of compaction. This underlines the complexity of the origin of the SIP signal as well as the difficulty to relate it to a single structural factor of a studied sample, and hence raises some fundamental questions with regard to the practical use of SIP measurements as site- and/or sample-independent predictors of the hydraulic conductivity.

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Controls on induced polarization in sandy unconsolidated sediments and application to aquifer characterization

Geophysics ◽

10.1190/1.1620628 ◽

2003 ◽

Vol 68 (5) ◽

pp. 1547-1558 ◽

Cited By ~ 91

Author(s):

L. D. Slater ◽

D. R. Glaser

Keyword(s):

Grain Size ◽

Hydraulic Conductivity ◽

Internal Surface ◽

Ionic Mobility ◽

Induced Polarization ◽

Hysteretic Behavior ◽

Degree Of Saturation ◽

Unconsolidated Sediments ◽

Fluid Conductivity ◽

Grain Diameter

Resistivity and induced polarization (IP) measurements (0.1–1000 Hz) were made on clay‐free unconsolidated sediments from a sandy, alluvial aquifer in the Kansas River floodplain. The sensitivity of imaginary conductivity σ″, a fundamental IP measurement, to lithological parameters, fluid conductivity, and degree of saturation was assessed. The previously reported power law dependence of IP on surface area and grain size is clearly observed despite the narrow lithologic range encountered in this unconsolidated sedimentary sequence. The grain‐size σ″ relationship is effectively frequency independent between 0.1 and 100 Hz but depends on the representative grain diameter used. For the sediments examined here, d90, the grain diameter of the coarsest sediments in a sample, is well correlated with σ″. The distribution of the internal surface in the well‐sorted, sandy sediments investigated here is such that most of the sample weight is likely required to account for the majority of the internal surface. We find the predictive capability of the Börner model for hydraulic conductivity (K)estimation from IP measurements is limited when applied to this narrow lithologic range. The relatively weak dependence of σ″ on fluid conductivity (σw) observed for these sediments when saturated with an NaCl solution (0.06–10 S/m) is consistent with competing effects of surface charge density and surface ionic mobility on σ″ as previously inferred for sandstone. Importantly, IP parameters are a function of saturation and exhibit hysteretic behavior over a drainage and imbibition cycle. However, σ″ is less dependent than the real conductivity σ′ on saturation. In the case of evaporative drying, the σ″ saturation exponent is approximately half of the σ′ exponent. Crosshole IP imaging illustrates the potential for lithologic discrimination of unconsolidated sediments. A fining‐upward sequence correlates with an upward increase in normalized chargeability Mn, a field IP parameter proportional to σ″. The hydraulic conductivity distribution obtained from the Börner model discriminates a hydraulically conductive sand–gravel from overlying medium sand.

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