Hydrogeological Characteristics Research Articles

Evaluation of Hydrogeological Characteristics of Aquifers in Altun Kopri Basin, Northeastern Iraq

The current research aims to evaluate the hydrogeological characteristics of the water-bearing layers in the study area. Because of the absence of observation wells near the pumping wells, the single pumping test experiment was achieved at seven wells, GW1, GW2, GW8, GW9, GW11, GW13, and GW16, distributed in the study area. The pumping test records were analyzed using Aquifer Test 2016.1 software, which is based on four methods: Theis, Hantush, Cooper-Jacob, and Theis recovery. The average values of transmissivity for the upper aquifer in the study area ranged between 13.4 m2/ day and 279 m2/ day, while the hydraulic conductivity ranged between 0.162 m/day and 4.14 m/day, and the storativity was 0.166 and 0.826. For the lower aquifer, the transmissivity ranges between 11.4 m2/ day and 177 m2/ day, the hydraulic conductivity is 0.214 m/ day and 1.17 m/ day, and the storativity is 0.0791 and 0.99.

City-scale heating and cooling with aquifer thermal energy storage (ATES)

Sustainable and climate-friendly space heating and cooling is of great importance for the energy transition. Compared to conventional energy sources, Aquifer Thermal Energy Storage (ATES) systems can significantly reduce greenhouse gas emissions from space heating and cooling. Hence, the objective of this study is to quantify the technical potential of shallow low-temperature ATES systems in terms of reclaimable energy in the city of Freiburg im Breisgau, Germany. Based on 3D heat transport modeling, heating and cooling power densities are determined for different ATES configurations located in an unconsolidated gravel aquifer of varying hydrogeological subsurface characteristics. High groundwater flow velocities of up to 13 m d−1 cause high storage energy loss and thus limit power densities to a maximum of 3.2 W m−2. Nevertheless, comparison of these power densities with the existing thermal energy demands shows that ATES systems can achieve substantial heating and cooling supply rates. This is especially true for the cooling demand, for which a full supply by ATES is determined for 92% of all residential buildings in the study area. For ATES heating alone, potential greenhouse gas emission savings of up to about 70,000 tCO2eq a−1 are calculated, which equals about 40% of the current greenhouse gas emissions caused by space and water heating in the study areas’ residential building stock. The modeling approach proposed in this study can also be applied in other regions with similar hydrogeological conditions to obtain estimations of local ATES supply rates and support city-scale energy planning.

On tectonic, lithological-stratigraphic, hydrological and hydrogeological features of the territory of Karabakh

Based on information from prospecting and exploration work in recent years, the article briefly discusses the tectonic structure, lithological-stratigraphic, hydrological and hydrogeological characteristics of the Karabakh territory. It is noted that hydrologically the entire territory of Azerbaijan, including the territory of Karabakh, the river network is unevenly located. The main rivers are Kendelanchay and Guruchay, taken from the springs of Mount Chakhmag in the Lesser Caucasus Ridge with their tributaries. The economic territory of Karabakh includes the Beylagan, Aghjabadi, Jabrayil, Khojavend regions, located in the southeastern foothill continuation of the Lesser Caucasus and bordered by the Araz River in the southeast, generally located at an altitude of 300 m above sea level, it is located in the southeast of the Karabakh Highlands.

Impact of Hydrogeological Characteristics on the Development of Underground Space Resources in Valley Cities

The development of urban underground space is a crucial aspect of current urban development. However, various factors pose challenges during the development process. In particular, in the valley cities of western China, groundwater has a significant impact on the utilization of underground space. This study focuses on understanding the influence of hydrogeological characteristics on the development of underground space in Ledu District, Haidong. Firstly, the hydrogeological characteristics of the aquifer in the study area are analyzed to determine the recharge and discharge characteristics. The dynamic changes in the groundwater table over time are then examined. Subsequently, the hydrochemical characteristics of groundwater are investigated to expound on the influence mechanism of groundwater on the development of underground space resources in Ledu District. The study reveals that the hydrodynamic effect of groundwater in the study area is substantial and has a significant physical scouring effect on underground structures. The fluctuation of groundwater levels affects the stability of buildings by increasing groundwater buoyancy. Additionally, this fluctuation also leads to engineering and environmental problems such as differential settlement and land salinization. The chemical characteristics of groundwater primarily impact the stability of building foundations through the corrosive effects of groundwater composition. This research clarifies the influence mechanism of groundwater on the development of underground space in typical valley cities of western China. The findings have practical significance for the evaluation, planning, development, and utilization of urban underground space resources in Haidong.

老虎台矿68003工作面水文地质特征及涌水量预计

老虎台矿68003工作面水文地质特征及涌水量预计

Izbor metoda razrade bunara na primeru izvorišta mineralne vode "Vitinka polja" u Kozluku (Bosna i Hercegovina)

In the area of Kozluk near Zvornik, the presence of mineral water was established at the end of the 19th century, while the first collection works were carried out in 1954. During 2002 and 2003, the author of the paper carried out investigative works, which enabled the capture of mineral water and its bottling. The research of this part of the terrain has continued until today, and the author of the paper carried out additional research during 2023. The results contributed to a better knowledge of the geological structure and hydrogeological characteristics of the terrain, all for the purpose of building a new water well. After the drilling of the water well, the development phase followed, which is often crucial for the successful completion of the works. In their practice, the authors were convinced that the capacity of the well depends on the correct choice of the development method, as well as the development regime itself. The capacity of the same water well can be several times higher, depending on the choice of methods and proper development regime. This paper presents the results of the applied development methods, as well as the optimization of the well development regime depending on the characteristics of the aquifer.

Aquifer systems in dry regions: Hydro-geophysical and geochemical investigations providing insights into water resources in southeast Tunisia

Water demands from agriculture and industry have intensified groundwater extraction, prompting a focused study to bolster water resources, particularly at Gabès region (Southeastern Tunisia). Through extensive geologic and geophysical investigations, the reservoir geometry and structural architecture of crucial aquifers, notably the Mio-Plio-Quaternary and Cretaceous aquifers have been studied. The integration of geochemical and geophysical data allows for a nuanced assessment of fault structures and groundwater hydrodynamics. Advanced techniques, like horizontal gradient and upward extension unveils structural features and density contrasts with precision. This study extends to a spatiotemporal analysis of aquifer hydrodynamics and groundwater mineralization. The Gabès aquifer system exhibits four groundwater facies: Ca–Mg–SO4, Na–Cl–NO3, Ca–Mg–HCO3, and Na–K–HCO3. Results reveal relative isotopic depletion, suggesting recharge under colder climates and at higher altitudes. However, the study underscores the impact of climate change, with increasing temperature and dwindling precipitation in North Africa, since the mid-20th century. This research is a relevant contribution to sustainable water management by emphasizing the impact of climate change scenarios and groundwater resources management. The detailed exploration of hydrogeological characteristics and aquifer dynamics in the Gabès region is pivotal on effective management of groundwater resources strategies in semi-arid environments.

Combination of Vertical Electrical Sounding (VES) and Electrical Resistivity Tomography (ERT) techniques for hydrogeological reconnaissance in the Guigou plain, Tabular Middle Atlas, Morocco

The study site is located in the Guigou plain, which is situated on the south-eastern edge of the Tabular Middle Atlas and is characterised by a particular geology within the mountainous region. Unlike the Tabular Middle Atlas, which is generally covered by Lias carbonate formations, the Guigou plain is characterised by the presence of a different type of cover formed by basaltic flows of plioquaternary age, forming a surface layer that is used extensively for agricultural activities. The main objective of our study is to detect the different geoelectric levels both at the surface and at depth, thus providing indications of the specific aquifer formations in the region studied. The analysis of the results obtained highlighted the presence of a superficial resistant level, attributed to basalts of Plio-Quaternary age, with an estimated thickness of between 30 and 100 m, forming the superficial aquifer of the plain. Next, a conductive level was identified, associated with alternating marl and marl-limestone of Pliocene age, in keeping with the local geology. Finally, at a depth of 225 m, a very resistant level was identified, corresponding to Lias limestone, which becomes a deep aquifer on the Guigou plain. This study provides essential vertical hydrogeological reconnaissance and highlights the need to carry out numerous tomographic profiles as well as electrical boreholes. These combined approaches are crucial to enriching our understanding of the particular geological and hydrogeological characteristics of this region, which forms a transition zone between the MAT and the MAP.

顾北矿浅埋煤层覆岩风化带工程及水文地质特征研究

顾北矿浅埋煤层覆岩风化带工程及水文地质特征研究

Geotechnical and Hydrogeological Features and Specific Solutions for the Strengthening Measures in the Construction of the Metro in Sofia

Geotechnical and Hydrogeological Features and Specific Solutions for the Strengthening Measures in the Construction of the Metro in Sofia

A comparison of methods for assessing groundwater vulnerability in karst aquifers: the case study of Terminio Mt. aquifer (Southern Italy)

The assessment of groundwater vulnerability to pollution is becoming even more important all over the world due to the increase of impacts of human activities on groundwater resources and the related risks to the human health, economics, and the environment. Owing to the variability of methods known for estimating groundwater vulnerability, basically depending on hydrogeological parameters considered and the scale of analysis, the comparison of results of different methods appears straightforward for identifying the best approach in a given hydrogeological condition and reference scale. In such a view, this work attempts to assess the groundwater vulnerability of the Terminio Mt. karst aquifer, by applying four different groundwater vulnerability methods, index-based, and comparing results in order to identify the best performing one in karst environments. The study aquifer, located in the Picentini Mts Regional Park (Campania region, southern Italy) represents a strategic drinking water resource since Roman times and hosts massive groundwater resources which outflow mainly from tapped basal and subordinately perched springs.The peculiar characters of the study karst aquifer, which favour direct infiltration and groundwater recharge processes, as well as the occurrence of industrial, agricultural and grazing activities, make it very vulnerable to groundwater pollution, thus requiring a proper and careful territorial management.Beside the most frequently and generally used methods for assessing groundwater vulnerability, such as the DRASTIC and SINTACS, also DAC and COP methods specifically designed for karst aquifers were applied and mutually compared. Results of SINTACS, DRASTIC and DAC methods show groundwater vulnerability maps of the Terminio Mt. karst aquifer as chiefly characterized by two classes of intrinsic groundwater vulnerability, varying between the medium and high degrees. Furthermore, high and extremely high values of groundwater vulnerability were found in areas controlled by the shallow depth of the water-table. Instead, the COP method resulted as the most effective in identifying the endorheic areas and the related karst morphologies as very high groundwater vulnerability zones, therefore the most suitable in capturing specific hydrogeological features of karst areas that control groundwater pollution and vulnerability.Results obtained will support decision tools aimed at the land use planning and protection of karst aquifers from pollution in karst areas.

Vulnerability and Risk of Contamination of the Varaždin Aquifer System, NW Croatia

This paper presents the first study that assesses the vulnerability and risk of contamination of groundwater in the Varaždin aquifer system. The alluvial aquifer system is mostly unconfined with favorable hydrogeological features. Out of three wellfields, two still operate at full capacity, while the Varaždin wellfield, once the major source of drinking water, has been abandoned due to high concentrations of nitrates in the groundwater. Index-based methods are employed to assess groundwater vulnerability—two DRASTIC-based methods, standard and P-DRASTIC; two SINTACS-based methods, with normal and severe weighting strings; and the GOD method. Hazard is evaluated according to recommendations from the EU COST 620 action, while the risk intensity of the resource is calculated using the results of vulnerability and hazard assessments. The results reveal that for all vulnerability models, the resulting maps have a similar distribution pattern of vulnerability classes, with the high vulnerability class prevailing. However, notwithstanding the generally high groundwater vulnerability, a moderate resource contamination risk prevails as a consequence of a dominantly low hazard index. The validation of the groundwater vulnerability models demonstrates a weak correlation between the vulnerability indices and mean nitrate concentrations in groundwater. Conversely, a significantly higher correlation coefficient (0.58) is obtained when the groundwater vulnerability index is replaced by the resource risk intensity index, indicating that the results of resource risk intensity assessments are superior to groundwater vulnerability results in predicting the level of groundwater contamination.

Combining Radon Deficit, NAPL Concentration, and Groundwater Table Dynamics to Assess Soil and Groundwater Contamination by NAPLs and Related Attenuation Processes

Soil and groundwater contamination by NAPLs (Non-Aqueous Phase Liquids) is certainly a big issue for protecting the environment. In situ clean-up actions are routinely applied to mitigate the risk and are supplemented by monitoring surveys to assess the degree, extension, and evolution of the contamination. Radon gas is here used as a tracer of contamination because of its high solubility in non-polar solvents that produce a reduced concentration of the gas in polluted soil and groundwater with reference to radon levels in adjacent “clean” areas. This approach was employed in two sites where gasoline and diesel spillage occurred, causing soil and groundwater contamination. The two case studies were chosen because of their difference in terms of the hydrogeological features, age of the spillage, composition of residual NAPLs, and clean-up measures to test the advantages and limits of this approach in a variety of settings. Radon data, NAPL concentration in the groundwater (mainly total hydrocarbons, Methyl Tertiary-Butyl Ether and Ethyl Tertiary-Butyl Ether) and the depth of the groundwater table were periodically collected in surveys that spanned a period of two years. This dataset was statistically processed using principal component analysis to unravel which factors and attenuation processes are working in the sites and the response of the radon deficit approach to this complex series of phenomena concurrently occurring there.

Хидрогеоложки условия в Ботевградската котловина

Groundwater in the Botеvgrad Kettle (West Bulgaria) is important for the local population. Despite the information available for this area, the catchment area of this kettle is poorly studied from a hydrogeological perspective. Therefore, the objective of this current study is to assess the hydrogeological conditions based on existing information for the purpose of better water resource utilization. Using GIS and data from the Geological Map 1:100000 and Hydrogeological Map 1:200000, water types in the Botеvgrad Kettle watershed and their spatial distribution in the area have been determined. The primary focus is on the region's most water-abundant hydrogeological unit, the Quaternary aquifer. Using various GIS layers that characterize spatial changes in hydrogeological characteristics, a conceptual model for this horizon has been developed, facilitating the initiation of activities related to numerical modeling.

Enhancing Accuracy of Groundwater Level Forecasting with Minimal Computational Complexity Using Temporal Convolutional Network

Multiscale forecasting of groundwater levels (GWLs) is essential for ensuring the sustainable management of groundwater resources, particularly considering the potential impacts of climate change. Such forecasting requires a model that is not only accurate in predicting GWLs but also computationally efficient, ensuring its suitability for practical applications. In this study, a temporal convolutional network (TCN) is implemented to forecast GWLs for 17 monitoring wells possessing diverse hydrogeological characteristics, located across South Korea. Using deep learning, the influence of meteorological variables (i.e., temperature, precipitation) on the forecasted GWLs was investigated by dividing the input features into three categories. Additionally, the models were developed for three forecast intervals (at 1-, 3-, and 6-month lead times) using each category input. When compared with state-of-the-art models, that is, long short-term memory (LSTM) and artificial neural network (ANN), the TCN model showed superior performance and required much less computational complexity. On average, the TCN model outperformed the LSTM model by 24%, 21%, and 25%, and the ANN model by 24%, 37%, and 47%, respectively, for 1-, 3-, and 6-month lead times. Based on these results, the proposed TCN model can be used for real-time GWL forecasting in hydrological applications.

Groundwater heavy metal(loid)s risk prediction based on topsoil contamination and aquifer vulnerability at a zinc smelting site

Groundwater pollution is a recurrent problem in abandoned non-ferrous metal smelting sites, and its severity is influenced by topsoil contamination, hydrogeological characteristics, and hydrogeochemical conditions. In such unique areas, traditional methods for evaluating groundwater pollution risk are biased, as the long production history of these sites have led to highly polluted and heterogeneous soil and groundwater. Herein, based on a typical lead-zinc smelting site, As, Pb, Zn, Cd, Mn, and Ni were found to be the predominant heavy metal (loid)s in groundwater, with respective exceedance rates of 44.4%, 50.0%, 72.2%, 88.9%, 88.9%, and 61.1%. Combined with the groundwater pollution characteristics, the representative hydrogeochemical factors were screened out to optimize the following aquifer vulnerability evaluation using the AHP-DRASTICH method. A comprehensive evaluation model (DI-NCPI) for groundwater pollution risk was established by combining the DRASTICH index (DI) obtained after optimization and the Nemerow comprehensive contamination index (NCPI) of topsoil. The fit between DI-NCPI and groundwater heavy metal (loid) pollution index reached 0.956, which laterally confirms that the model has some reference value. In terms of distribution, the high-risk and very high-risk zones were mainly concentrated in the zinc smelting system, located in the southeastern and central-western parts of the site. These areas have relatively high levels of topsoil contamination and aquifer vulnerability and require focused attention in site remediation. This research highlights the importance of combining topsoil contamination and aquifer vulnerability to evaluate groundwater pollution risk in smelting areas. It provides a more targeted reference for groundwater remediation strategies in abandoned smelting sites, as well as severely polluted industrial areas.

Optimisation of rock mass quality parameters for the initial geotechnical investigation of a vertical shaft: Gosowong Gold Mine Project Case Study - North Halmahera

This article presents a case study that highlights the importance of a thorough geotechnical assessment at an early stage of project development. Shaft ventilation is one of the critical elements in underground mines, providing oxygen and ensuring air quality for breathing, removing noxious gases from equipment and explosions, reducing the natural temperature of the rock, and more, so stability analysis is required for design and strategy prior to shaft opening. Through extensive field surveys, drilling and laboratory testing, the project team has gathered data to assess rock quality parameters, including rock strength, geological structure and hydrogeological characteristics. The McCracken and Stacey (MS) method is one such empirical approach to assist shaft development risk assessment. The results of this analysis allowed the identification of potentially unstable zones. It was concluded that 45% of the planned ventilation shafts have stability problems due to rock mass variations. The risk value of the shaft development plan was obtained with a high failure risk of 25%, a medium failure risk of 33% and a low failure risk of 42% based on the raise bore quality index (QR).

Hydrological modelling of large-scale karst-dominated basin using a grid-based distributed karst hydrological model

Hydrological modelling is important to flood hazard prevention in the flood-prone karst area of Southwest China. Due to the special hydrogeological features with strong spatial heterogeneities and whose information is rarely obtained in large-scale karst-dominated basins; thus, it’s still a challenge to conduct accurate sub-daily distributed precipitation-streamflow simulation in these regions. To reveal the characteristics of hydrological response and the inertia of karst systems that are influenced by the spatial heterogeneity of the degree of karstification, a new Grid-based Distributed Karst Hydrological Model (GDKHM) is developed by this study to simulate streamflow in Li River Basin (LRB), which is a typical large-scale karst-dominated basin of Southwest China. The GDKHM considers the duality of hydrological behavior and the spatial heterogeneities of land uses types and karstification of each grid and river channels routing characteristics between different sub-basins. The results show the GDKHM using calibrated parameters could reflect the spatial distribution characteristics of hydrological response in the LRB. The mean NSE, KGE, R2 and RRE of the streamflow of all the sub-basin outlets during validation period reached 0.82, 0.84, 0.83 and 4.64%, respectively. The hydrograph simulation result of nested interior grid without recalibration was also satisfied. Furthermore, the GDKHM was able to reproduce the Auto-correlation function (ACF) shapes of simulated lateral inflow time series in sub-basins with different percentage of karst terrain areas (PKTAs) during validation period, and the ACF characteristics information including memory effect, slopes of rapid-conduit and slow-matrix flow phases could be captured, which indicates the model can characterize the spatial variability of karst system inertia in large karst basin. Due to the better performance in hydrograph and ACF of streamflow, GDKHM has the potential to successfully support flood forecasting in large-scale karst-dominated basins.

Dominant factors determining the hydraulic conductivity of sedimentary aquitards: A random forest approach

Aquitards are common hydrogeological features and their hydraulic conductivity is an important property for various groundwater management issues. Predicting their hydraulic conductivity proves challenging, given its dependence on numerous variables. In this study, the dominant factors for predicting aquitard hydraulic conductivity are identified. To this end, a random forest model is trained on a dataset consisting of more than 1000 hydraulic conductivity measurements of core-scale sediment samples from a wide range of stratigraphic units and depths in the Netherlands. The dataset contains textural properties, such as the grain size distribution and porosity, as well as structural data, such as location, sampling depth, stratigraphical unit, lithofacies, organic carbon content, carbonate content and groundwater chloride concentration. Results show that clay fraction, stratigraphic unit, depth, lithofacies and x-coordinate are the most important features for predicting the hydraulic conductivity. Here, x-coordinate is presumably a proxy for distance from marine influence. Using a more detailed grain size distribution or using derived parameters such as the grain size percentiles does not improve the model any further. Our findings indicate that structural properties play a significant role in predicting aquitard conductivity, as they serve as indicators of processes such as compaction and soft-sediment deformation. The model is furthermore an effective method to estimate hydraulic conductivity for sediment samples without conducting costly and time-consuming hydraulic conductivity measurements.

Identification of groundwater potential zones in data-scarce mountainous region using explainable machine learning

Groundwater is a critical resource, yet its detailed assessment in mountainous regions is challenged by varying topography, complex hydrogeological characteristics and limited data. In this study, machine learning approaches were used to analyze the groundwater potential in five different watersheds in Nepal. Explainable machine learning models (EBM and GAMI-net) were used to identify zones with different groundwater potentials and controlling factors. The models were validated with k-fold cross-validation using the area under the receiver operating characteristics curve for the two groundwater potential models with unseen validation dataset of 0.87 and 0.88 respectively. We found that precipitation, elevation, soil bulk density, slope and lineaments primarily controls the groundwater potential in the study regions. The expected impact of each of the factors on groundwater potential was complex and multimodal. The results of this study can be used to improve water resource management and ensure sustainable groundwater use in the region.