Hydrogeologic Units Research Articles

Temporal and Spatial Diversity of Renewable Groundwater Resources in the River Valley

Quantitative assessment of the amount of renewable resources allows their evaluation, valorization and protection in terms of the possibility of their environmental management under climate change conditions. The aim of the study was to determine the amount of renewable resources in the Middle Vistula valley, in the region of the Kampinos National Park, central Poland. The amount of renewable resources was calculated on a hydrodynamical model for three variants, as the average, the lowest and the highest infiltration recharge rate for a specified period of 1999–2013. The modelling research was conducted in a strongly differentiated hydrogeological valley unit, in which several geomorphological units could be delineated: the floodplain, over-flood terraces and the plain area. The hydrodynamic modelling results were verified by comparing the obtained data with both the amount of drainage in the valley zone and the underground streamflow. The assessment of renewable groundwater resources in three distinctive variants was the basis for calculating the groundwater footprints, defined as a quantitative assessment of the groundwater use in climate change conditions.

GEOELECTRICAL INVESTIGATION OF GROUNDWATER QUALITY THROUGH ESTIMATES OF TOTAL DISSOLVED SOLIDS AND ELECTRICAL CONDUCTIVITY IN PARTS OF AKWA IBOM STATE, SOUTHERN NIGERIA

This paper presents the results of a geophysical investigation of groundwater quality in parts of Akwa Ibom State, Southern Nigeria. A total of 11 vertical electrical soundings (VES) was carried out in the study area using the Schlumberger electrode configuration. The results of the interpretation show that the area comprises 4 geoelectric layers. The third layer constitutes the major economic hydrogeological unit in the area and has resistivity of between 50.3 Ωm and 2088.9 Ωm and thickness of between 36.8 m and 149.0m respectively. The groundwater quality was assessed through estimates of the electrical conductivity and total dissolved solids in water. The conductivity ranges from 74.5 to 604.4µS/cm with an average value of 244.0µS/cm while the TDS values range from 47.7 to 386.8 ppm with an average value of 156.1 ppm. Based on these values, which are within the permissible limits, the water is considered to be fresh and suitable for drinking and other domestic/agricultural usages. The results show excellent correlation between the estimated TDS and the Dar-zarrouk parameters (longitudinal conductance and transverse resistance) on one hand and the aquifer bulk resistivity on the hand which demonstrate the ease of deriving TDS from surface resistivity data.

The Influence of Hydrogeology to Generation of Hydrogen Sulfide of Low-Rank Coal in the Southeast Margin of Junggar Basin, China

The salinity, chemical properties, and migration characteristics of groundwater in coal measures are the key factors that affect the generation, migration, and reservoir of hydrogen sulfide (H2S) in low-rank coal seams. Taking the Jurassic coal and rock strata in the southeastern margin of the Junggar basin as the research object, according to the hydrogeological characteristics of the coal measures, the region is divided into 4 hydrogeological units. The coalbed methane contains a large number of secondary biogas. Along the direction of groundwater runoff, the salinity and the pH value increase gradually. The salinity in the hydrogeological units is low; it is not conducive to the propagation of sulfate-reducing bacteria and the formation of hydrogen sulfide of the Houxia, the south of Manasi River, and Hutubi and Liuhuangou area, the western region of the Miquan. The high salinity center and depressions of low water level (hydrodynamic stagnation zone) in the hydrogeological unit of the Liuhuanggou and the Miquan are the main areas for the production and enrichment of H2S in the low-rank coal. The high salinity in water is formed by infiltration, runoff, and drought evaporation. At the same time, the deep confined water environment closed well; in conditions of hydrocarbon-rich, under the action of sulfate-reducing bacteria, bacterial sulfate reduction will occur and hydrogen sulfide formed. According to the circulation characteristics of water bearing H2S in the region, imbricate and single bevel two kind generation and enrichment mode of hydrogen sulfide under the action of hydrodynamic control. The solubility of hydrogen sulfide in pure water and solutions of NaCl and Na2SO4 with different molar concentrations was calculated. The H2S solubility of groundwater in coal measures of 4 hydrogeological units was estimated.

Integrating In-Situ Data and RS-GIS Techniques to Identify Groundwater Potential Sites in Mountainous Regions of Taiwan

Due to rapid urbanization, the development of megacities and metropolises worldwide is creating water scarcity, social-environmental risk, and challenges to the regions where water supply from rivers and alluvial aquifers is insufficient and unstable. Groundwater exploration in fractured bedrock of mountainous regions is thus a crucial issue in the search for substitute water resources. To achieve cost effectiveness on groundwater exploration, the use of comprehensive remote sensing (RS)- and geographic information system (GIS)-based models appears feasible. The required parameters selected and analyzed from the literature depend on the hydrogeological characteristics. This study intends to investigate and improve the proposed parameters and data sources upon those presented in the literature. A total of 17 hydrogeological units of concern was delineated from 105 complex geological formations of the geological sections and main rock types. The other parameters related to groundwater potential were derived from the digital elevation model and Landsat imagery. In addition, 118 drilling cores were inspected and in-situ well yield data from 72 wells were employed to assess the normalized groundwater potential index in the raster-based empirical GIS model with a higher spatial resolution. The results show that the accuracy of the interpretation of groundwater potential sites improved from 48.6% to 84.7%. The three-dimensional (3D) visualization of a thematic map integrated with satellite imagery is useful as a cost-effective approach for assessing groundwater potential.

A comparative analysis of methods for mapping groundwater pollution hazard: application to the Gallocanta Hydrogeologic Unit (Spain)

Anthropogenic activities are the main sources of groundwater pollution. In order to prevent groundwater degradation and to apply suitable mitigation measures, hazard maps are a useful instrument for decision makers. The ultimate goal of the research is to analyse the effectiveness of several groundwater hazard indexes at the Gallocanta Lagoon Basin. To do so, the Hazard Index, the Danger of Contamination Index and the Pollutant Origin and its Surcharge Hydraulically method were applied and compare, and the potentialities and weaknesses of the resulting maps have been analysed. Accurate hazard maps were obtained and, based on their methodological approach, significant differences were found in relation to the rating process, the inventory of the sources, and the treatment of quantity and likelihood. In the light of the results, the indexes tended to undervalue the hazard level of agricultural activities, which were the main sources of pollution of the study area. Therefore, due to the characteristic land uses of the study area, typical of the Mediterranean context, some proposals to improve the indexes have been suggested.

Seismic refraction study, single well test and physical core analysis of anthropogenic degraded Peat at the Badas Peat Dome, Brunei Darussalam

The Badas peat dome located in the Belait district is one of the biggest peat domes in Brunei. Over the years, this area has seen a noticeable loss of peatland due to fires and infrastructure development. In this paper, the anthropogenic effects on the Badas peat dome were studied for three survey areas using seismic refraction surveys, core analysis and single well tests. Satellite images were used to confirm the extent of past peat fires in the area. Using these methods, this study has identified multiple peat, sand and clay layers demonstrating the stratigraphic heterogeneity that can be present in tropical peatlands. In particular, a sand horizon underlying the peat deposits was identified which has the potential to be a significant hydrogeological flow unit. Groundwater level interpretations from 2D velocity data were correlated to groundwater levels from coring. In order to determine the degradation impact on peat through lowering of groundwater levels using these methods we produced a subsurface reconstruction at two locations with different levels of peat degradation. Single well tests conducted in this study showed that disturbed peat had lower hydraulic conductivities with an average of 1.73 × 10−5 m/s compared to undisturbed peat with an average of 6.66 × 10−5 m/s. A combination of these methods (seismic refraction, single well test and coring) are suitable for identifying different levels of peat degradation. In addition, these methods can be suitable for profiling in tropical peatlands, for identifying groundwater levels as wells as identifying significant hydrogeological flow units.

Nation-wide estimation of groundwater redox conditions and nitrate concentrations through machine learning

The protection of water resources and development of mitigation strategies require large-scale information on water pollution such as nitrate. Machine learning techniques like random forest (RF) have proven their worth for estimating groundwater quality based on spatial environmental predictors. We investigate the potential of RF and quantile random forest (QRF) to estimate redox conditions and nitrate concentration in groundwater (1 km × 1 km resolution) using the European Water Framework Directive groundwater monitoring network as well as spatial environmental information available throughout Germany. The RF model for nitrate achieves a good predictive performance with an R2 of 0.52. Dominant predictors are the redox conditions in the groundwater body, hydrogeological units and the percentage of arable land. An uncertainty assessment using QRF shows rather large uncertainties with a mean prediction interval (MPI) of 53.0 mg l−1. This study represents the first nation-wide data-driven assessment of the spatial distribution of groundwater nitrate concentrations for Germany.

Contributions for Conceptual Geohydraulic Model of the Underground Hydric Resources of Meda Municipality

This paper presents contributions on underground hydric and geothermal resources of the Meda Municipality land. After a brief introduction about the importance of the theme, the Meda municipality’s administrative, geographic, geomorphological and geological frameworks are presented in a synthetic way. The main hydrogeological units of the municipality are presented below and, based on the water surpluses resulting from precipitation, the order of magnitude of the water reserves of those hydrogeological units is advanced. From a vast field survey of groundwater points on the various hydrogeological units, the results obtained from the expeditious physicalchemical parameters are presented, and based on them some waters were selected to carry out complete physical-chemical and some isotopes analyses. Based on all the results, the municipality was organised in three different major hydrogeological domains (Longroiva, Areola, and Graben), for which the conceptual geohydraulic model was developed. From the several results, it is emphasized in particular that in the various domains there are potential to explore special groundwater with characteristics not only for medical spa and aqua-ludic spaces, but also for the production of energy and even not only heat energy, with cascading uses, but also for the production of electricity from groundwater from 70 to 113∘C.

Assessment of Hydrogeological Potential and Aquifer Protective Capacity of Odeda, Southwestern Nigeria

Abstract Hydrogeological assessment of groundwater resources was carried out with a view to evaluate the potential of the aquifers to provide portable water supply and access the distribution of electrical parameters of hydrogeologic units in some areas in Odeda, Ogun State, Nigeria. A geophysical survey using vertical electrical sounding (VES) with the Schlumberger electrode array, with half-current electrode spacing (AB/2) varying from 1 to 132 m was carried out at 30 different stations in the study area. The VES data were interpreted qualitatively and quantitatively. Three-to-five sub-surface layers consisting of topsoil, weathered layer consisting of clay, sandy clay, clayey sand and sand layers, and fractured/fresh basement were delineated. Layer resistivities and thicknesses obtained on the curves within the study area showed one main aquifer type, which is the fractured basement. The longitudinal unit conductance (ranging from 0.049720 to 1.4520000 mhos) of the study area aided the protective capacity to be rated into good, moderate and weak. About 33% of the study area falls within the weak protective capacity, 57% falls within the moderate protective capacity and 10% falls within the good protective capacity.

Appraisal of Hydraulic Flow Units and Factors of the Dynamics and Contamination of Hydrogeological Units in the Littoral Zones: A Case Study of Akwa Ibom State University and Its Environs, Mkpat Enin L.G.A, Nigeria

Appraisal of Hydraulic Flow Units and Factors of the Dynamics and Contamination of Hydrogeological Units in the Littoral Zones: A Case Study of Akwa Ibom State University and Its Environs, Mkpat Enin L.G.A, Nigeria

Features of the hydrogeological stratification of oil and gas bearing deposits in the western part of the Yenisei-Khatanga basin

The article presents results and findings of the research into stratification of the hydrogeological section of western areas of the Yenisei-Khatanga basin localized in the Siberian Arctic zone. The identified two hydrogeological structural stages in the study area include the Paleozoic (undivided), Triassic, Lower-Middle Jurassic, Upper Jurassic, Neocomian, Aptian-Albian-Cenomanian, Upper Cretaceous and Paleogene-Quaternary water-bearing complexes. There have been recognized as many as eleven aquifers and eleven confining beds formed within the area where the established hydrogeological units are found not ubiquitously distributed, which is associated with the sedimentary basin evolution. A considerable part of the horizons have failed to be included in the hydrogeological section either due to the erosion processes within the Messoyakha inclined ridge or their pinching out in the borders of the basin.

Characterising variations in the salinity of deep groundwater systems: A case study from Great Britain (GB)

Study regionThe study region is Great Britain (GB), a small non-continental island landmass in North West Europe Study focusData for Total Dissolved Solids (TDS) from groundwater samples can be used to characterise regional-scale variations in the quality of deep groundwater systems. Combined with information about typical well-depths, TDS data can be used to identify the presence of currently undeveloped fresh or brackish groundwater at depth that may require protection. This study considers the distribution of TDS with depth relative to sea level in the main GB aquifers and selected other key hydrogeological units, and demonstrates how useful insights can be obtained from data-led analyses of depth variations in groundwater chemistry if the regional context of hydrogeological systems is taken into account. New hydrogeological insightsIn GB, TDS varies over about five orders of magnitude, up to about 330,000 mg/L, with a general increase in mineralisation with depth. Overall, there is a transition from fresh <1625 mg/L to brackish <10,000 mg/L groundwater at about 500 m below surface, and from brackish to saline >10,000 mg/L groundwater at about 700 m. Given that the 95 %tile depth of water wells is about 200 m, it is evident that there is currently undeveloped fresh groundwater at depth across large parts of the study area that may require protection, although it is inferred that TDS is not the only factor limiting exploitation and use of these deeper resources. As in this study, previous data-led analyses of fresh groundwater at depth have typically analysed TDS as depth below surface. However, if TDS data is analysed relative to sea level and in the context of regional hydrogeological information or models, additional insights can be gained on the distribution and controls on fresh groundwater at depth. Projecting TDS data into a 3D hydrogeological model of the study area shows that fresh groundwater at depth exhibits spatial coherence and is generally associated with relatively deep sedimentary basins overlying older, less permeable basement.

Vertical Discretization Impact in Numerical Modeling of Matrix Diffusion in Contaminated Groundwater

AbstractUnderstanding the effects of contaminants that can diffuse into low‐permeability (“low‐k”) zones is crucial for effective groundwater remedial decision‐making. Because low‐k zones can serve as low‐level sources of contamination to more transmissive zones over time, an accurate evaluation of the impacts of matrix diffusion at contaminated sites is vital. This study compared numerical groundwater flow and transport simulations using MODFLOW/RT3D at a hypothetical site using three cases, each with increasing discretization of the vertical 10‐m thick domain: (1) a coarse multilayer heterogeneous grid based on one layer for each of four different hydrogeological units, (2) a “low‐resolution” discretization approach where the low‐k units were divided into several sublayers giving the model 10 layers, and (3) a “high‐resolution” numerical model with 199 layers that are a few centimeters thick. When comparing the results of each case, significant differences were observed between the discretizations used, even though all other model input data were identical. The conventional grid models (Cases 1 and 2) appeared to underestimate groundwater plume concentrations by a factor ranging from 1.1 to 36 when compared to the high‐resolution grid model (Case 3), and underestimated predicted cleanup times by more than a factor of 10 for some of the hypothetical sampling points in the modeling domain. These results validate the implication of Chapman et al. (2012), that conventional vertical discretization of numerical groundwater flow and transport models at contaminated sites (with layers that are greater than 1 m thick) can lead to significant errors when compared to more accurate high‐resolution vertical discretization schemes (layers that are centimeters thick).

Uranium isotopes as tracers of groundwater evolution in the Complexe Terminal aquifer of southern Tunisia

The Complexe Terminal (CT) multi-layer aquifer is formed by Neogene/Paleogene sand deposits, Upper Senonian (Campanian-Maastrichtian limestones) and Turonian carbonates. The chemical composition and isotopes of carbon and uranium were investigated in groundwater sampled from the main hydrogeological units of the (CT) aquifer in southern Tunisia. We paid special attention to the variability of uranium contents and isotopes ratio (234U/238U) to provide a better understanding of the evolution of the groundwater system. Uranium concentrations range from 1.5 to 19.5 ppb, typical of oxic or mildly reducing conditions in groundwaters. The lowest concentrations are found southeast of the study area, where active recharge is supposed to take place.When looking at the isotope composition, it appears that all the samples, including those from carbonate levels, are in radioactive disequilibrium with significant 234U excess. A clear-cut distinction is observed between Turonian and Senonian carbonate aquifers on the one hand, with 234U/238U activity ratios between 1.1 and 1.8, and the sandy aquifer on the other hand, showing higher ratios from 1.8 to 3.2. The distribution of uranium in this complex aquifer system seems to be in agreement with the lithological variability and are ultimately a function of a number of physical and chemical factors including the uranium content of the hosting geological formation, water-rock interaction and mixing between waters having different isotopic signatures. Significant relationships also appear when comparing the uranium distribution with the major ions composition. It is noticeable that uranium is better correlated with sulfate, calcium and magnesium than with other major ions as chloride or bicarbonate.The 14C activities and δ13C values of DIC cover a wide range of values, from 1.1 pmc to 30.2 pmc and from −3.6‰ to −10.7‰, respectively. 14C model ages estimated by the Fontes and Garnier model are all younger than 22 Ka and indicate that the recharge of CT groundwater occurred mainly during the end of the last Glacial and throughout the Holocene.

Mechanisms of groundwater arsenic variations induced by extraction in the western Hetao Basin, Inner Mongolia, China

High arsenic (As) groundwater has posed a serious threat to human health. Due to the complex spatial-temporal distributions of dissolved As, the influence of groundwater extraction on As enrichment has attracted great attention. To ascertain spatial-temporal variations in dissolved As and driving mechanisms impacted by extraction, we monitored groundwater levels and chemicals in different aquifers in the western Hetao basin, China. Results revealed that groundwater levels decreased during irrigation season in both shallow (<40 m below land surface (bls)) and deep (>42 m bls) aquifers, and the decreases in deep aquifer were more evident. During irrigation, the estimated proportion of recharge from shallow groundwater to affected deep groundwater (around 45 m bls) increased from 21% to 53% in the distal of the alluvial fan and sharply from 53% to 86% in the flat plain. In the distal of the alluvial fan, the vertical recharge of shallow groundwater with low As concentrations (<10 μg/L) directly decreased dissolved As concentrations in deep groundwater, and the introduced oxygen-containing groundwater promoted As fixation. In the flat plain, As concentrations of affected deep groundwater increased by around 80% during irrigation, which may result from the direct introduction of dissolved As, labile organic matter and high Na/Ca0.5 molar ratio from shallow groundwater. The latter two promoted As release by enhanced dissimilatory reduction of Fe oxyhydroxides and As desorption, respectively. The two-year monitoring data of conservative tracers and dissolved As concentrations in irrigation wells also validated the hypothesis. This study highlights the different variation patterns of deep groundwater As concentration impacted by extraction in different hydrogeological units, and provides an insight into mechanisms of As variations impacted by anthropogenic activity.

Hydrologic response in the karstic and basaltic hydro-geological units of Lake Kinneret watershed

The hydrologic responses of two similar in size watersheds in the Lake Kinneret basin are examined: Karstic Hermon watershed and basaltic Meshushim watershed. The streamflow properties at these watersheds are different in their surface flow to baseflow ratio, runoff coefficients and response to extreme rainfall events. The HYdrological Model for Karst Environment (HYMKE) model, developed to simulate daily flow in karst formation, was modified to address the basaltic formation at the Meshushim watershed. Water fluxes simulations were used to compare the hydrologic processes between the watersheds. The twice-higher annual precipitation in the Hermon watershed, generates annual streamflow that is five times more than in the Meshushim. This amplification of the rainfall-streamflow ratio between the watersheds is because larger fraction of the rainfall is lost to evapotranspiration at the basaltic Meshushim watershed and larger portion of the rainfall percolates to the karstic aquifer through preferential flow and appear as baseflow at the Hermon watershed. During large rainfall events when soil water content is near saturation, lower rainfall amount over the Meshushim watershed generates larger peak flow than the Hermon watershed. In both watersheds, surface flow was generated only when the soil water content is at or near saturation conditions. The streamflow dependency on soil water content, suggests high sensitivity of streamflow generation to the intra-annual variability of precipitation. Understanding the hydrologic response of the different sources of Lake Kinneret improves the ability to forecast its inflow.

Hydrogeological characteristics of foot caves in a karst peak-forest plain in South China

In karst areas of South China, isolated peaks in peak-forest plains often have foot caves near the water table. Originally, foot caves are formed by surface water on the plain flowing through the peak foot into the underground during the rainy season. Later, surface water might not flow into some foot caves anymore, but foot caves still connect with groundwater. Understanding the role of foot caves is important in comprehending regional groundwater flow and in controlling the damage caused by groundwater flow in cave sites. This study employed a multi-electrode resistivity method to locate karst voids or caves at Zengpiyan cave site, Guilin City (Guangxi Province). Boreholes were used to detect karst features, tracer tests were adopted to assess the flow path and velocity of groundwater, and hydrological observations were conducted on site to reveal groundwater changes. Of the 26 boreholes drilled, 14 found underground caves, with heights ranging from 0.3 to 17.5 m. Groundwater was stored and flowed in four distinct media zones: concentrated flow zone (CFZ), highly fractured zone, cave sediment zone, and matrix-with-fractures zone, in which the foot caves constitute the primary groundwater flow zone. The CFZ was characterized and found to have a minimum hydraulic slope of 0.2%. Thus, the study succeeded in identifying hydrogeological characteristics of foot caves in a karst peak-forest plain and a hydrogeological model of the foot caves was developed. The methodology provides a basis for flood control and groundwater pollution prevention in the hydrogeological unit in which foot caves are located.

Regulation storage calculation and capacity evaluation of the underground reservoir in the groundwater overdraft area of northern China

Economic developments and a lack of surface water resources often result in the overexploitation of the groundwater, which lead to groundwater funnels, land subsidence, groundwater pollution and other environmental geological disasters. This phenomenon is particularly serious in developing countries. In such circumstances, to accurately calculate the regulation storage of the underground aquifers, evaluate the capacity of an underground reservoir and to restore the groundwater funnels are of great significance to the control of groundwater overexploitation at a global scale. In this paper, a calculation method for regulation storage of an underground reservoir is introduced, and the storage capacity is determined. First, the groundwater overdraft and hydrogeological materials are collected, and the geological structure to partition the hydrogeological units is analyzed. The representative drills are chosen, and profiles are drawn to describe the spatial distributions of the aquifers. Then, based on the lithology, the study area is divided into different hydrogeological units. Finally, the regulation storage is calculated using the volumetric method. In addition, using Surfer software, the second method is used to verify the calculation results. Through the establishment of a comprehensive evaluation index system for the underground reservoir regulation capacity, a gray correlation analysis of the index system is conducted, and the indices are reduced to six. Then, the regulation capacity is evaluated using the projection pursuit model. Taking Weifang of northern China as an example, the regulation storage is calculated and the regulation capacity is evaluated.

Geophysical assessment of aquifer vulnerability and management: a case study of University of Nigeria, Nsukka, Enugu State

Seventeen vertical electrical soundings and seven electrical resistivity tomography profiles were carried out at the University of Nigeria, Nsukka, Enugu State, Nigeria. The study involves the use of Schlumberger and Wenner electrodes configuration. The thrust of this work is on determining the vulnerability of the hydrogeological units by employing the aquifer vulnerability index (AVI) method. The resistivity data measured were interpreted manually and with computer software packages, which gave the resistivity, depth and thickness for each layer within the maximum current electrodes separation. The hydraulic conductivity (K) and hydraulic resistance (C) of the protective layers estimated from the primary parameters estimated have values ranging from 0.0434 to 0.4890 m day−1 and 38.37 to 1005.84 day−1, respectively. AVI of the study shows that the study area is characterised by low to high AVI with moderate AVI as dominant. This is to help in delineating aquifer protective zones and also possible locations, which further helps in groundwater resource exploration and management.

Investigating karst aquifers: Using pseudo 3-D electrical resistivity tomography to identify major karst features

This work presents the electrical resistivity imaging of the Hydrogeological Experimental Site (HES) karst aquifer of Poitiers (France) from pseudo three-dimensional (3-D) Electrical Resistivity Tomography (ERT), i.e., a three-dimensional model obtained from the joint inversion of resistivity data collected along parallel profiles. The inverse resistivity model provided a fairly reliable definition of the main hydrogeological units. The survey also allowed the recognition of possible shallow dissolution-enlarged fractures that do not show any ground expression at present but have been revealed at depth by vertical flowmeter data and high-resolution video footage from wells. These features seem to connect with middle-depth sub-vertical features down to a depth of 25 m, which are likely to correlate with soil-mantled, incipient sinkhole formation features that do not show any ground expression at present, as well as karst conduits. At greater depth, the resistivity model allowed the recognition of the first two main karst intervals (35–40 m and 85–87 m deep) associated with water productive layers, as revealed by well logs. The opportunity to cross-validate geophysical results with extensive ground truth provided by the HES allowed an assessment of the error the pseudo 3-D ERT model makes in estimating the depth of the karst intervals. Synthetic dataset modelling provided the detectability of the pseudo 3-D ERT model in identifying karst intervals. Synthetic dataset modelling also allowed an estimation of the response of the experimental and inversion setup to a variable degree of heterogeneity of the aquifer, using well-log data as geological a priori information.