Coupling ground and airborne geophysical data with upscaling techniques for regional groundwater modeling of heterogeneous aquifers: Case study of a sedimentary aquifer intruded by volcanic dykes in <scp>N</scp>orthern <scp>I</scp>reland

Dickson, Neil; Comte, Jean-Christophe; McKinley, Jennifer; Ofterdinger, Ulrich

doi:10.1002/2014wr015320

Cited by 21 publications

(42 citation statements)

References 105 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…All studies indicated that borehole logs and groundwater level measurements were used to constrain the model. In a recent study by Dickson et al (2014), structural information directly namely the Sherwood Sandstone Group (SSG), which is the country's principal aquifer for industrial use and domestic supply, commonly named the Lagan Valley Aquifer. The SSG is bounded by Silurian rocks outcropping to the south-east and upland Palaeogene chalk and basalt to the north-west.…”

Section: Multiple-point Statistics and Direct Sampling Techniquementioning

confidence: 99%

“…The effect of dykes on groundwater flow is acknowledged by previous authors as acting as relative barriers to flow: the hydraulic effect is described in Bennett (1976), Kalin and Roberts (1997), Burns et al (2010), Wilson (2011) and numerous consultancy studies involving hydraulic testing. Despite those references, few (Wilson 2011;Comte et al 2012;Dickson et al 2014) have actually attempted to quantify both the properties of dykes and their effect at local to regional scales. Prior to the detailed multi-scale modelling works by Dickson et al (2014), modelling studies by Cronin et al (2000), Yang et al (2004) and Cronin et al (2005) mention that dykes were taken into account through compartment zonation of approaches can be used to integrate an exhaustive map of geophysical data in the MPS framework.…”

Section: Multiple-point Statistics and Direct Sampling Techniquementioning

confidence: 99%

“…Despite those references, few (Wilson 2011;Comte et al 2012;Dickson et al 2014) have actually attempted to quantify both the properties of dykes and their effect at local to regional scales. Prior to the detailed multi-scale modelling works by Dickson et al (2014), modelling studies by Cronin et al (2000), Yang et al (2004) and Cronin et al (2005) mention that dykes were taken into account through compartment zonation of approaches can be used to integrate an exhaustive map of geophysical data in the MPS framework. The most frequent use is to derive facies-occurrence probability maps from the geophysical data and then to account for those probabilities during the MPS simulation process (Allard et al 2012;Caers et al 2003).…”

Section: Multiple-point Statistics and Direct Sampling Techniquementioning

confidence: 99%

“…More specifically, it is proposed to assess the potential of applying MPS-DS to airborne geophysical data in order to statistically improve the spatial resolution of dyke location (and therefore the distribution of aquifer hydraulic properties for groundwater modelling) by overcoming the noise in the input data and as an alternative to the manual processing performed by Dickson et al (2014). It is important to emphasize that, in this study, a perfect groundwater model is not sought, rather an improved model-a model which shows improved fit to observed head data compared to a simpler conceptualization for the region.…”

Section: Multiple-point Statistics and Direct Sampling Techniquementioning

confidence: 99%

“…The creation of the TI was informed by previous studies of the area (Dickson et al 2014) and from existing literature (Bennett 1976;Hartley 1935) where a general trend orientation of dyke intrusions is observed. The TI were created by digitizing existing magnetic lineaments and enlarging the resulting polyline locations to a width of 200 m wide each, as this was the average thickness observed across the region.…”

Section: Mps Data Preparation: Training Images and Simulation Gridmentioning

confidence: 99%

See 4 more Smart Citations

Integrando dados geofísicos aéreos em simulações estatísticas multi-ponto para auxiliar modelos de fluxo de águas subterrâneas

et al. 2015

Self Cite

View full text Add to dashboard Cite

The process of accounting for heterogeneity has made significant advances in statistical research, primarily in the framework of stochastic analysis and the development of multiple-point statistics (MPS). Among MPS techniques, the direct sampling (DS) method is tested to determine its ability to delineate heterogeneity from aerial magnetics data in a regional sandstone aquifer intruded by low-permeability volcanic dykes in Northern Ireland, UK. The use of two two-dimensional bivariate training images aids in creating spatial probability distributions of heterogeneities of hydrogeological interest, despite relatively 'noisy' magnetics data (i.e. including hydrogeologically irrelevant urban noise and regional geologic effects). These distributions are incorporated into a hierarchy system where previously published density function and upscaling methods are applied to derive regional distributions of equivalent hydraulic conductivity tensor K. Several K models, as determined by several stochastic realisations of MPS dyke locations, are computed within groundwater flow models and evaluated by comparing modelled heads with field observations. Results show a significant improvement in model calibration when compared to a simplistic homogeneous and isotropic aquifer model that does not account for the dyke occurrence evidenced by airborne magnetic data. The best model is obtained when normal and reverse polarity dykes are computed separately within MPS simulations and when a probability threshold of 0.7 is applied. The presented stochastic approach also provides improvement when compared to a previously published deterministic anisotropic model based on the unprocessed (i.e. noisy) airborne magnetics. This demonstrates the potential of coupling MPS to airborne geophysical data for regional groundwater modelling.

show abstract

Section: Multiple-point Statistics and Direct Sampling Techniquementioning

confidence: 99%

Section: Multiple-point Statistics and Direct Sampling Techniquementioning

confidence: 99%

Section: Multiple-point Statistics and Direct Sampling Techniquementioning

confidence: 99%

Section: Multiple-point Statistics and Direct Sampling Techniquementioning

confidence: 99%

Section: Mps Data Preparation: Training Images and Simulation Gridmentioning

confidence: 99%

See 3 more Smart Citations

Integrando dados geofísicos aéreos em simulações estatísticas multi-ponto para auxiliar modelos de fluxo de águas subterrâneas

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

Integrating multiple scales of hydraulic conductivity measurements in training image-based stochastic models

et al. 2015

View full text Add to dashboard Cite

Hydraulic conductivity is one of the most critical and at the same time one of the most uncertain parameters in many groundwater models. One problem commonly faced is that the data are usually not collected at the same scale as the discretized elements used in a numerical model. Moreover, it is common that different types of hydraulic conductivity measurements, corresponding to different spatial scales, coexist in a studied domain, which have to be integrated simultaneously. Here we address this issue in the context of Image Quilting, one of the recently developed multiple-point geostatistics methods. Based on a training image that represents fine-scale spatial variability, we use the simplified renormalization upscaling method to obtain a series of upscaled training images that correspond to the different scales at which measurements are available. We then apply Image Quilting with such a multiscale training image to be able to incorporate simultaneously conditioning data at several spatial scales of heterogeneity. The realizations obtained satisfy the conditioning data exactly across all scales, but it can come at the expense of a small approximation in the representation of the physical scale relationships. In order to mitigate this approximation, we iteratively apply a kriging-based correction to the finest scale that ensures local conditioning at the coarsest scales. The method is tested on a series of synthetic examples where it gives good results and shows potential for the integration of different measurement methods in real-case hydrogeological models.

show abstract

Effect of volcanic dykes on coastal groundwater flow and saltwater intrusion: A field‐scale multiphysics approach and parameter evaluation

Comte

Wilson

Ofterdinger

et al. 2017

Water Resources Research

View full text Add to dashboard Cite

Volcanic dykes are common discrete heterogeneities in aquifers; however, there is a lack of field examples of, and methodologies for, comprehensive in situ characterization of their properties with respect to groundwater flow and solute transport. We have applied an integrated multiphysics approach to quantify the effect of dolerite dykes on saltwater intrusion in a coastal sandstone aquifer. The approach involved ground geophysical imaging (passive magnetics and electrical resistivity tomography), well hydraulic testing, and tidal propagation analysis, which provided constraints on the geometry of the dyke network, the subsurface saltwater distribution, and the sandstone hydrodynamic properties and connectivity. A three‐dimensional variable‐density groundwater model coupled with a resistivity model was further calibrated using groundwater and geophysical observations. A good agreement of model simulations with tide‐induced head fluctuations, geophysically derived pore water salinities, and measured apparent resistivities was obtained when dykes' hydraulic conductivity, storativity, and effective porosity are respectively about 3, 1, and 1 orders of magnitude lower than the host aquifer. The presence of the dykes results in barrier‐like alterations of groundwater flow and saltwater intrusion. Preferential flow paths occur parallel to observed dyke orientations. Freshwater inflows from upland recharge areas concentrate on the land‐facing side of the dykes and saltwater penetration is higher on their sea‐facing side. This has major implications for managing groundwater resources in dyke‐intruded aquifers, including in coastal and island regions and provides wider insights on preferential pathways of groundwater flow and transport in highly heterogeneous aquifer systems.

show abstract

Coupling ground and airborne geophysical data with upscaling techniques for regional groundwater modeling of heterogeneous aquifers: Case study of a sedimentary aquifer intruded by volcanic dykes in Northern Ireland

Cited by 21 publications

References 105 publications

Integrando dados geofísicos aéreos em simulações estatísticas multi-ponto para auxiliar modelos de fluxo de águas subterrâneas

Integrando dados geofísicos aéreos em simulações estatísticas multi-ponto para auxiliar modelos de fluxo de águas subterrâneas

Integrating multiple scales of hydraulic conductivity measurements in training image-based stochastic models

Effect of volcanic dykes on coastal groundwater flow and saltwater intrusion: A field‐scale multiphysics approach and parameter evaluation

Contact Info

Product

Resources

About