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Dam construction has some qualitative and quantitative effects on groundwater resources. This effect may be in the form of an increasing groundwater table or a changing groundwater system. In this paper, the effect of the Rodbal dam construction on the Darab aquifer was investigated. For this paper water table levels from observation wells and precipitation data was used. The study aims to analyse the behaviour of the water table during precipitation by employing a combination of the standardisation process, Fuzzy Inference System (FIS), and Root Mean Square Error (RMSE) calculations. Fuzzy logic involves the fuzzification of input data, transforming precise values into fuzzy sets. The effectiveness of the FIS is highlighted, particularly in determining the number of membership functions for inputs. The performance of the results is assessed using indicators such as RMSE and Coefficient of Determination (R2). The FIS showed a high level of effectiveness in performance assessment, exhibiting a 70% similarity between the fuzzy and Mann–Kendall methods. Nonetheless, the Fuzzy Purpose Method corresponded more closely with the observed data, indicating a more accurate reflection of reality. The findings indicate that for P3, P7, and P8, the results from the Mann–Kendall method do not show a discernible trend. Conversely, the proposed Fuzzy method accounts for changes in the behaviour of these piezometers. [ABSTRACT FROM AUTHOR]

The roof water inrush disaster induced by coal mining is becoming a vital bottleneck restricting mine safety. To accurately predict the water inrush position of the coal seam roof sandstone aquifer and accurately prevent and control it, this paper takes Lilou Coal Mine in Juye Coalfield as an example. Based on the comprehensive analysis of hydrogeological data, drilling data, and geophysiological data, this paper examines the water richness of the roof aquifer, the water insulation and geological structure, and the fracture development characteristics of the roof aquifer. Starting from the general side, nine factors, including fault strength index, tectonic intersection point, tip extinguishing point, development height of water conduction crack zone, roof sandstone aquifer thickness, aquifer drilling unit inrush, geophysical prospecting water-rich anomaly area, roof key layer thickness, roof aquifer thickness, brittle plastic rock thickness ratio, etc., form the roof plate roof. The main control factors for water inrush are deeply discussed. Through the spatial analysis function of GIS, unique drawings of different evaluation indicators are drawn, and the data are normalized. Combined with the AHP hierarchical analysis method, the corresponding weight is determined. Finally, a comprehensive water inrush risk assessment map of the roof of coal seam 3 in Lilou Coal Mine is obtained. Through the verification of the coal mine water inrush survey ledger over the years, it has been found that the evaluation results of the coal seam roof water inrush model are consistent with the actual situation. The evaluation results are reasonable and accurate, which can provide a reference basis for coal seam mining and water damage prevention and control in the future. [ABSTRACT FROM AUTHOR]

Groundwater is a valuable shared resource in the Moulouya Basin, but it has been in decline due to recent years of low rainfall and rapid population growth. To support socio-economic development, there is increased demand for this precious resource. This paper presents a standard methodology for delimiting potential groundwater zones using geographic information systems (GIS), an integrated analytical hierarchy process (AHP), and remote sensing techniques. Seven parameters that monitor the presence and mobility of groundwater, including drainage density, lithology, slope, precipitation, land use/land cover, distance to river, and lineament density, were incorporated into a raster data model using ArcGIS software. AHP-based expert knowledge was used to prepare a groundwater potential index and assign weights to the thematic layers. The study classified the area into five zones of varying groundwater potential: very high (26%), high (51%), moderate (13%), poor (9%), and very poor (1%). The accuracy of the model was validated by comparing the Groundwater Potential Zones map with data from 96 wells and boreholes across the basin. The validity of the results was confirmed by comparing them with the specific yield of the aquifer in the study area, yielding a high correlation coefficient (R2) of 0.79. The analysis revealed that 89.5% of the boreholes were situated in the high and very high potential zones, demonstrating the reliability and robustness of the employed approach. These findings can aid decision-making and planning for sustainable groundwater use in the water-stressed region. [ABSTRACT FROM AUTHOR]

The aim of this paper is to provide insight into research and activities of in situ remediation to remove petroleum hydrocarbon pollutants from a contaminated aquifer's sediment, located near two radial collector wells of a water supply system. It was decided that the most appropriate method for remediation of this aquifer's sediment is in situ bioremediation because it is clean, efficient and sustainable technology. Before the start of the bioremediation process, it was necessary to isolate and cultivate the microorganisms present at the contamination site, so they could be later applied in the bioremediation process. The samples before and after the bioremediation were studied using both GC and GC × GC–MS to determine how the concentrations of contaminants changed over time. Additionally, in this paper, a spatiotemporal representation of the change in hydrocarbon content by depth within the zone of the highest contamination over time is shown. After 12 months of bioremediation, the hydrocarbon content in the samples decreased by 82.0%, and based on GCxGC-MS analysis, the order of degradation of various hydrocarbon groups was as follows: steranes (99.6%), isoprenoids (98.4%), benzene derivatives (98.4%), alkanes (97.2%), and terpenes (49.3%). The exponential decay model showed the greatest decomposition rate of hydrocarbons occurred at depths of 8–10 m, with an average decay constant of 0.227, independent of the initial concentration of hydrocarbons. To the best of our knowledge, to date, the described approach has not been applied to an aquifer (the simultaneous treatment of groundwater and its associated sediment layers). [ABSTRACT FROM AUTHOR]

Improving the living conditions of campo residents requires access to drinking water. The surface and subsurface factors of a region influence the groundwater potential zones. The main objectives of this paper are to identify suitable groundwater zones for productive drilling and to assess groundwater mineralization in the coastal aquifers of the study area. Geographic Information Systems (GIS) and Analytical Hierarchy Process (AHP) were used in the methodology to generate the groundwater potential map. Lithology, geomorphology, specific capacity, hydraulic conductivity, transmissivity, rainfall, infiltration rate, lineament density, drawdown, static water level, soil thickness, drainage density, slope, and land use/land cover were taken into account to characterize the groundwater potential zones. Weights were assigned to the various parameters and their characteristics according to their impact on groundwater recharge. The groundwater potential map of Campo was classified into four zones namely: very low 783.5 km2 (28.9%), low 835.2 km2 (31.9%), moderate 858.4 km2 (31.7%) and high 199.9 km2 (7.3%). Multivariate statistical analysis was used to understand groundwater mineralization. Two phenomena are responsible for the mineralization of water: a process of interaction between water and rock; and a process of salinization resulting from natural phenomena or anthropic activities. The present study could guide hydrogeological investigations and groundwater resource management planning in the study area. [ABSTRACT FROM AUTHOR]

Groundwater resource plays a central role in every sector of life globally. Unfortunately, the roles of groundwater are often unappreciated in many parts of the world, especially in developing nations. The paper applied a combined geo-electrical method and hydrochemical analysis alongside physical surveys to investigate aquifer promising zones, the quality and the source of water supply in the selected regions. The geo-electric resistivity data were used to select the most aquifer-promising zone for groundwater development with a key interest in groundwater potential and aquifer overburden protective capacity overlying the water-bearing unit. Seventeen (17) vertical electrical sounding (VES) acquired in four regions reveals that the regional weathered/fractured unit which constitutes the aquifer unity extends from 13.4 m to 41.3 m in depth with the subsurface resistivity value varying between 53 Ωm–1013 Ωm in terms of resistivity values. The overburdened thickness (protective soil layers) stretches from 2.5 m to 13 m with a resistive layer of resistivity values ranging from 111 Ωm to 2877 Ωm, which could provide high aquifer protective cover for the regional groundwater systems. The computed aquifer transmissivity and hydraulic conductivity range from 0.54 m 2 / h –15.85 m 2 / h , and 0.95 m/day–9.19 m/day, respectively. The estimated average longitudinal conductance (0.2 moh) reveals that the regional groundwater systems are moderately protective against surface contaminants. In addition, the physicochemical water analysis was examined, which exposes the level of heavy metals (HMs) compositions in the regional groundwater systems and the possible public health risks compared to WHO permissible drinking water limits. The sample water from the Rivers had the highest concentration of HMs (0.089 mg/I–2.012 mg/l), followed by the hand-dug wells (HWDs) (0.033 mg/l–1.555 mg/l) and the lowest in the borehole (0.011 mg/l–0.511 mg/l). In contrast, the borehole water sample shows a moderation where the HMs presence falls within the WHO standard for drinking water. The outcomes of the study show that 63% of the investigated region consumed water with a high concentration of HMs above the WHO permissible standard allowance for drinking water, while only 37% took water that falls within the WHO permissible standard. In conclusion, the study showed significant impacts of anthropogenic activities on the regional water quality, which provides vital information about the regional groundwater systems and the quality of water supply for adequate groundwater development and sustainability. [ABSTRACT FROM AUTHOR]

This paper presents some new analytical solutions to an accurate prediction of the behavior of the groundwater flow in aquifers in response to changes in surface water. The new analytical solutions are obtained using integral transforms. An anisotropic rectangular confined aquifer bounded with four time-varying streams is undertaken. The effects of anisotropy on groundwater head and flow rate near time-varying streams are investigated. Depending on the change rates of the streams level, an anisotropic aquifer may render either lower or higher hydraulic head than an isotropic aquifer. In addition, an anisotropic aquifer has provided less water exchange at the interfaces than an isotropic one. The sensitivity of the hydraulic head to change rate of the streams level in both isotropic and anisotropic aquifers is evaluated. It is shown that the aquifer response is more sensitive to change rate of the streams parallel to y-direction and less sensitive to change rate of the streams parallel to x-direction in an anisotropic aquifer and vice versa in an isotropic aquifer. The results of the present new analytical solutions are compared with numerical model of MODFLOW. The results obtained from the presented solutions showed good agreement with the results of MODFLOW. The results show that the presented new analytical solutions are accurate, robust and efficient. Therefore, the results indicate that the presented new analytical solutions are very effective in the simulation of the groundwater flow in river–aquifer systems. Furthermore, one of the advantages of the new analytical solutions is to investigate the sensitivity analysis of aquifer parameters, which has been carried out in this paper. Also, some other new analytical solutions for steady-state conditions and sudden fall in streams level are provided as well. Feasibility of the proposed new analytical solutions is presented via calculating and simulating the hydraulics of groundwater flow in river–aquifer systems by means of integral transforms. [ABSTRACT FROM AUTHOR]

The interaction of mining and the surface water or aquifer system in varying overburden strata conditions is one of the most critical aspects of sustainable mining practices, that can lead to water loss or water inrush into openings. This paper examined this phenomenon in a complex strata condition via a case study, and proposed a new mining design to minimize the impact of longwall mining on the overlaying aquifer. A range of factors have been identified contributing to the potential disturbance of the aquifer, including the extent of the water-rich area, the characteristics of overburden rock units, and the development height of the water-conducting fracture zone. In this study, the transient electromagnetic method and the high-density three-dimensional electrical method were used to identify two areas prone to water inrush danger in the working face. The vertical range of the water-rich abnormal area 1 is 45–60 m away from the roof, with an area of 3334 m2. The vertical range of the water-rich abnormal area 2 is 30–60 m away from the roof, with an area of approximately 2913 m2. The bedrock drilling method was used to determine that the thinnest part of the bedrock, with a thickness of approximately 60 m, and the thickest part, with a thickness of approximately 180 m. The maximum mining-induced height of the fracture zone was 42.64 m using empirical method, theoretical prediction based on the rock stratum group, field monitoring. In summary, the high risk area was determined, and the analysis shows that the size of the water prevention) pillar was 52.6 m, which was smaller than the safe water prevention pillar actually set in the mining range. The research conclusion provides important safety guidance significance for the mining of similar mines. [ABSTRACT FROM AUTHOR]

This paper presents the impact of livestock activities and geochemical processes on the water quality of a fractured volcanic rock aquifer in the Lake Çıldır watershed, located at the northeastern part of Turkey. The existence of a high livestock population and animal grazing activities in meadow and pasturelands of the watershed during the short summer period poses serious stress on both surface and groundwater resources being the only drinking water supply for the local communities. Therefore, understanding the effect of grazing and livestock breeding activities occurring in the recharge areas of the fractured volcanic rock aquifer is vital to take precautions in order to protect limited water supplies at the watershed and vulnerable lake ecosystem as well. The mean nitrate content of the groundwater was measured at 6.4 ± 6.6 (std. dev) mg/L in the wet (before grazing) period and 7.1 ± 5.9 mg/L in the dry (after grazing) period. Despite low nitrate concentration levels of groundwater, microbial contamination was observed in the spring waters at alarming levels especially after the animal grazing activities. 56%, 26%, and 11% of the groundwater samples showed bacterial contamination in terms of total coliform, fecal coliform, and fecal streptococci contents, respectively, prior to grazing activity, while in pursuit of intense livestock grazing at highland, these microbial indicators have been increased to 92%, 85%, and 77% in the dry period. A significant increase observed in fecal contamination indicates the negative impact of livestock activities on groundwater quality. Al (200–638 µg/L) and Fe (66–218 µg/L) enrichments locally observed in groundwater were related to advanced argillic alteration (kaolinization) and hematization zones in pyroclastic rocks. [ABSTRACT FROM AUTHOR]

Seawater intrusion is one of the causes of groundwater quality degradation in coastal zones. This phenomenon is intensified by overexploitation of coastal aquifers. In this paper, optimal management strategies have been determined to prevent the advance of seawater using a parallel simulation–optimization decision model. This model has been applied to a real case study of Ajabshir aquifer located in Urmia Lake basin, Iran, for a 20-year planning horizon (2015–2034). Four categorizes of new sustainability indices (indices of protection, reliability, vulnerability, and aquifer area with a groundwater problem) as the objective functions have been examined for the first time. The developed management problems based on these four categories have been solved under two different conditions of groundwater elevation and salinity concentration. The results of 20-year period simulations indicate that by changing the extraction pattern in different regions of the aquifer (as the decision variables) based on the solution of management problems, the largest decrease in net recharge (0.065 million cubic meters) occurs in the second half of the hydrologic year (October to March) compared to the continued condition in which all factors are similar to 2014. The contribution of using indices in this study can help the local water managers to identify the high-risk areas for better planning and other coastal settings. [ABSTRACT FROM AUTHOR]

Groundwater, is an alternative resource, is used as a supplement for irrigation as well as drinking purposes in Pakistan. This paper aims to determine the quantum and quality of groundwater in Matiari district of Sindh, Pakistan, through Electrical Resistivity Survey (ERS). The ERS was conducted at 52 location points using the ABEM Terrameter SAS 4000. The quantity of good quality groundwater has also been evaluated with ArcGIS interpolation techniques, i.e., the maximum percentage of fresh groundwater is 34% the marginal fresh groundwater 43% at the depth of with few patches of saline groundwater aquifers. Moreover, at 50-m depth, the percentage of fresh groundwater reduces to 21% and the marginal has increased to 48%. However, groundwater below the depth from 50 to 100 m was found only 8% fresh groundwater, 29% marginal, 49% salt water, and 14% high salt water. Analysis of groundwater samples for quality showed a good agreement with the quality obtained from VES results. In addition, a socio-economic survey of 55 tube well owners were conducted through interviews related to groundwater suitability and usage. According to the survey, about 62% of respondents are using good quality groundwater; however, 36% consuming the marginal and the remaining 2% are utilizing the hazardous quality of groundwater. The consumer satisfaction survey showed most farmers (89%) were satisfied with the groundwater usage, while 11% were unsatisfied due to poor-quality groundwater. The crop productivity could be enhanced through awareness and conjunctive use of marginal quality groundwater with the canal water. [ABSTRACT FROM AUTHOR]

An increasing number of cities are interested in deep geothermal energy in order to increase the share of renewable energies in their district heating networks. To reduce the risks related to deep geothermal energy operations, reliable digital models are needed: they make it possible to predict the depth of aquifers away from borehole locations, and their thermal and hydrological evolution by supporting detailed water and heat flow simulations. This paper presents a 3D geomodel developed for this purpose in the southern Paris Basin of France in the Orléans area. The 3D geomodel integrates various data such as reprocessed and interpreted seismic lines, well data, and a pre-existing larger-scale and lower-resolution 3D geological model. The resulting 3D geomodel gives a new and reliable representation of the main aquifers underlying the study area. Within the framework of the project, hydrological and thermal simulations were then performed based on this 3D geomodel. Other environmental investigations (e.g. CO2 storage) and teaching/communication activities could also benefit from the dataset. Measurement(s) geological features Technology Type(s) 3D geomodelling integration Sample Characteristic - Location Southern Paris Basin (France) [ABSTRACT FROM AUTHOR]

A critical understanding of the water crisis of Lake Urmia is the driver in this paper for a basin-wide investigation of its Meteorological (Met) droughts and Groundwater (GW) droughts. The challenge is to formulate a data-driven modelling strategy capable of discerning anthropogenic impacts and resilience patterns through using 21-years of monthly data records. The strategy includes: (i) transforming recorded timeseries into Met/GW indices; (ii) extracting their drought duration and severity; and (iii) deriving return periods of the maximum drought event through the copula method. The novelty of our strategy emerges from deriving return periods for Met and GW droughts and discerning anthropogenic impacts on GW droughts. The results comprise return periods for Met/GW droughts and their basin-wide spatial distributions, which are delineated into four zones. The information content of the results is statistically significant; and our interpretations hint at the basin resilience is already undermined, as evidenced by (i) subsidence problems and (ii) altering aquifers' interconnectivity with watercourses. These underpin the need for a planning system yet to emerge for mitigating impacts and rectifying their undue damages. The results discern that aquifer depletions stem from mismanagement but not from Met droughts. Already, migration from the basin area is detectable. [ABSTRACT FROM AUTHOR]

This research examines the implications of rainwater harvesting structure hapa in the Bankura district of West Bengal, India. The paper finds that proper management and harvesting of surface and subsurface runoffs in hapas can facilitate groundwater recharge and increase both net irrigated area and moisture in soil leading to higher cropping intensity and yield in dryland areas. However, dissected plateau and residual hillocks can reduce irrigation efficiency of hapas. Although sprinkler or drip irrigation along with cultivation of drought and lateritic resilient, low moisture crop can help in coping up with geophysical and climatic vulnerability, appropriate crop diversification is also necessary. There is also a need for regular maintenance and desiltation of hapas. The water user groups should play an active role for this, especially for hapas in common land. Further, scientific guidance is necessary for designing appropriate structure of hapas in different geo-physical conditions. [ABSTRACT FROM AUTHOR]

The groundwater system in the Rafsanjan aquifer perpetuated sustainably for decades before 1950s; however, its groundwater resources have been overexploited in the recent decades. In this paper, we aim to investigate the water governance system to understand the reasons behind the ongoing overexploitation. Sustainability processes are considered a policy implementation problematic. As such, we employ the contextual interaction theory as a policy implementation framework to assess the groundwater governance as part of the context for the conservation policy. Data for this qualitative research were gathered from legal texts, articles, technical reports, and multiple interviews with authorities and groundwater users. The assessment results revealed that the poor quality of the governance system is central to the ineffectiveness of the conservation policies. Findings of this paper can be relied on to devise tools to underpin an appropriate context to sustain groundwater resources. [ABSTRACT FROM AUTHOR]

Over the last three to four decades, several methods for assessing groundwater vulnerability to anthropogenic pollution have been developed. Researchers and policymakers have widely used these methods for preventing groundwater pollution through knowledge about particularly vulnerable areas. This systematic review presents different and significant methods for assessing the vulnerability of aquifers for the protection of the resource. Previous studies mentioned that formulating a single technique for assessing groundwater vulnerability is difficult; thus, different methods and techniques have been proposed. Therefore, this paper presents three methods, namely, DRASTIC, GOD, and susceptibility index (SI), which will be discussed in detail, and highlights their advantages and limitations. In doing so, the study introduces the concept of aquifer vulnerability, and further discussion will be devoted to the three methods. Lastly, the study outlines the major challenges to the assessment of aquifer vulnerability. The review concludes the importance of groundwater vulnerability and strategies for preserving its quality. [ABSTRACT FROM AUTHOR]

To study and prevent the water hazards of deep coal mines roof in the Inner Mongolia–Shaanxi (IM–S) mining area, it is essential to correctly evaluate the water-richness distributions of water-bearing aquifers in roof. This paper puts forward a sediment control method for water-richness law and zoning in the roof aquifers of deep Jurassic coals. To determine the vertical distance of direct water-bearing aquifers, the height of fractured water-conducting zone was detected by an underground network parallel electrical method. The plane and lateral spatial distribution patterns of the water-bearing aquifers and the control of the water-richness distribution was analyzed with the sediment control method. An evaluation system that consisted of four indicators, i.e., sedimentary environmental impact index, interlayer ratio of sandstone and mudstone, sandstone thickness, geophysical water-richness anomaly index was constructed. Furthermore, an Analytic Hierarchy Process (AHP) was introduced to establish the comprehensive zoning map. Finally, through the example analysis of Muduchaideng coal mine, the zoning evaluation results of water-richness were verified by the mine inflow. The findings of this study provide scientific guidance for prevention and control of mine water hazards in the IM–S mining area. [ABSTRACT FROM AUTHOR]

In order to accurately separate the elastic and inelastic deformation information caused by aquifer compression in the land subsidence signal, and to invert the hydrogeological parameters of high spatial and temporal resolution to better apply the groundwater-ground subsidence model, a CWT (Continuous Wavelet Transform) separation method for aquifer elastic and inelastic deformation signals based on CWT is adopted, and the deformation signal is extracted by InSAR technology. The large-scale synthetic aperture radar dataset obtained by Envisat satellite from 2007 to 2009 is collected to obtain the surface deformation characteristic of the area by SBAS-InSAR technology, and then the independence provided by the observation well is used. Using the independent water level data provided by the observation wells, combined with the vertical InSAR deformation component and the head data, the CWT method is used to separate the periodic deformation signal components and long-term trends. Finally, the isolated signal component is used to invert the elastic and inelastic storage coefficient based on the ground subsidence model. The settlement signal separation method used in this paper makes up for the shortcomings of the two kinds of information in the previous settlement signal that are difficult to separate, which allows for more accurate inversion of aquifer parameters and helps to understand the aquifer parameters and continuously manage groundwater resources. [ABSTRACT FROM AUTHOR]

In order to ensure the safety of mine production, it is of great practical significance to make a reasonable evaluation of the water-yield property (WYP) of a karst aquifer. In this paper, we selected fault-lines distribution, fault-scale index, aquifer thickness, water pressure, consumption of rinsing liquid, and hydraulic conductivity as the evaluation indexes to analyze the WYP of a karst aquifer. Meanwhile, the analytic hierarchy process (AHP) is used to calculate the subjective weight of indexes, and the coefficient of variation (CV) is used to calculate the objective weight of indexes. Combined with GIS, a multi-factor composite superposition is carried out to evaluate the WYP of a karst aquifer. The reliability of the research results is verified by the specific yield. Besides, for improving the reliability of evaluation results, the chemical composition of karst water was discussed. The results show that the selection of indexes is reasonable and the AHP–CV method is effective to evaluate the WYP of a karst aquifer. Therefore, on the premise of reasonable index selection, the evaluation models of AHP and CV can be used to evaluate the WYP of a karst aquifer and provide reference for coal mine water control measures. [ABSTRACT FROM AUTHOR]

Yushenfu mining area is located in an ecological fragile area in western China, the coal seam of which is the Jurassic Yan'an Formation. The Jurassic Yan'an Formation contains five minable coal seams, the top layer of which is thick, covered by shallow overburden and located under aquifers. Therefore, the mining induced water flowing fractured zone can easily extend to the aquifers of both the Quaternary Sarahu and Jurassic Zhiluo Formation. This would result in a series of negative hydrological and ecological effects, including groundwater leakage, groundwater lowering, furtherly causing surface vegetation withering and dying, surface water body reduction, spring drying out, and water flow of river being decreased substantially. To solve these environmental problems, several technologies have been carried out by Chinese scientists, one of which is water-preserved coal mining. This paper presents a review of the origin, definition and development of water-preserved coal mining, and its applications in Yushenfu mining area. The applicable conditions, research contents, research methodology, and technical foundation of water-preserved coal mining are addressed in this paper. The future research focuses regarding water-preserved coal mining in China are also discussed in this paper. Its results serve as a guide for selecting the methods to be preferred for mining in case the geological conditions, roof overburden structure and coal mining process are similar to Yushenfu mining area. [ABSTRACT FROM AUTHOR]

An approach has been made in this study to delineate the groundwater potential zones of the Varuna river basin, Uttar Pradesh, India, using the analytical hierarchy process (AHP) and multi-influence factor (MIF) techniques. The present groundwater estimation exhibits an increase in the draft (10%) due to expansion in population, agricultural extent, and industrialization, which ultimately causes water table depletion. This backdrop justifies the need for this particular analysis in the multilayer aquifers of the central alluvial zone. The shallow aquifers are silty and unconfined, whereas the deeper aquifers are coarse, sandy-gravelly, and semi-confined. Basement faults and highs often control the thickness of aquifers in the subsurface. The study considered an integrated approach of AHP and MIF methods with remote sensing and GIS approaches. Various themes (land use/land cover (LULC), soil type, geology, elevation, slope, rainfall, normalized difference vegetation index (NDVI), drainage density, recharge rate, groundwater depth) determined by considering different conditioning factors and eventually employed for computation of groundwater potential index (GWPI) and classified for identifying the groundwater potential zones (GWPZ). Two methods applied to capture the results in a more tangible form as the AHP model works on building a pair-wise comparison matrix to relate conditioning factors to each other. Still, the MIF model considered interrelations among the conditioning factors. The GWPZ of the study area generates with overlay weighted sum method by integrating all thematic layers. The resulting groundwater potential index map is categorized into three groundwater potential zones, namely good, moderate, and poor. Ultimately, by constructing the receiver operating characteristic (ROC) curves for both the groundwater potential models, determine the efficiency of performances and the GWPZ map validated using yield data collected from wells scattered over the study area. The findings of the present paper have important implications for ensuring exploration and sustainability groundwater plans in that particular area. [ABSTRACT FROM AUTHOR]

The landslide mechanism and failure mode of the gently sloping Piedmont region are analyzed in Fangshan and Zhutoushan hills in the Nanjing area of Jiangsu Province, China. These hills are underlain by volcanic rocks and have a distinctive stratigraphic structure composed of fill or clay at the surface, coarse-grained soil or fully weathered rock in the middle, and highly or moderately weathered rock at the bottom. Landslides occurred during or after heavy rainfall, and the monitored displacements of the slope surface indicated that sliding had not stopped after a long period of continuous rainfall. Through monitoring of groundwater and simulation, we found that the low-permeability highly weathered rock can restrict the activity of the lower aquifer, resulting in a rapid rise of pore pressure and formation of confined water in response to rainfall, which can lead to slope failure. We discuss the mechanism and avulsed–drifted failure mode of the landslides considering seepage deformation and pressure balance. Finally, we propose appropriate control measures for these landslides. The results of this paper will contribute to prevention of similar landslide geological hazards. [ABSTRACT FROM AUTHOR]

The karst development makes aquifer have strong anisotropy and heterogeneity. In order to reveal the characteristics of solute transport in the karst fissure–conduit aquifer system, this study presents a physical model of fissure–conduit in laboratory experiments to carry out the solute transport simulation. In this paper, the tracer tests of fissure–conduit combination, fissure, and conduit solute transport process in saturated flow are designed. We found that different aquifer structures and tracer injection points have an influence on the shape of the breakthrough curve. Besides, the two-dimensional dispersion model of tracer injection of the instantaneous point was used to calculate the dispersion parameters of each group of experiments. Then, the dynamic responses of the linear distance (x) between the injection point and the receiving point, initial time (t0), peak time (tm), peak concentration (cm), average tracer transport velocity (V), and porosity (p) of aqueous media to the longitudinal dispersion coefficient are discussed. In addition, according to the measured data, Gaussian multi-peak fitting can be used to reflect the overall shape and change trend of the multi-peak BTC. These results demonstrate the solute transport behaviors in the saturated karst aquifer system, which have important reference significance for solving the engineering environmental problems in the karst area. [ABSTRACT FROM AUTHOR]

This paper is an attempt to utilize the various indices available to assess the degree of corrosivity and calcite formation of groundwater sampled from Indian Mk. II handpumps from the district of Mahoba in Uttar Pradesh. The indices used include Langelier Saturation Index, Ryznar Stability Index, Puckorius Scaling Index, Larson-Skold Index, and Potential to Promote Galvanic Corrosion. Corrosivity of groundwater would cause materials used in construction of pipes to leach into drinking water since the same is used for household activities and drinking purposes. Calcite formation would affect the amount of exertion used to manually pump out required quantity of groundwater from the aquifer as it reduces the convey potential of pipes. One hundred five groundwater samples were collected from Indian Mk. II handpumps tapping shallow aquifer (up to 35mbgl) from different locations that were used by locals for analysis of basic parameters like pH, TDS, EC, ions like calcium, magnesium, sodium, potassium, chloride, carbonate, bicarbonate, sulphate, etc. Overall, majority of the groundwater samples display tendency to deposit calcium carbonate within the pipes, chlorides and sulphates not interfering with natural film formation in pipes and possibility of galvanic corrosion, whereas minority of the samples indicate the alternate scenario. [ABSTRACT FROM AUTHOR]

In arid and semi-arid areas with limited surface water resources, the daily life and the growth of various economic sectors depend on the provision of services by the groundwater ecosystem. In many countries, groundwater is the main source of freshwater. In addition, groundwater plays an important role within the water cycle, and as such, it feeds and sustains groundwater-dependent ecosystems (such as rivers and wetlands). Therefore, sustainable management of groundwater resources is necessary. Groundwater footprint indicator is a useful tool for assessing the sustainable use of groundwater resources and its associated ecosystem services. In this paper, the sustainable use of groundwater in 28 main alluvial aquifer systems of West Azarbaijan province in the west of Lake Urmia-Northwest of Iran has been investigated by the groundwater footprint indicator. In order to assess the aquifers' water quality sustainability for agricultural use, the integrated groundwater footprint indicator developed by Kourgialas et al. (2018)—based on GIS spatial analysis—has been used. This assessment can help water sector managers in adopting policies and measures to the sustainable management of the alluvial aquifer system. Due to the availability of sufficient data for all aquifers in 2011, the calculations were performed only for this year. The results showed that no aquifer has a sustainable use of groundwater resources. Also, 16 aquifers do not have qualitative sustainability due to salinity pollution. The results of implementing three applicable policy options to improve the quantitative and qualitative sustainability of aquifers showed that it is possible to change quantitative sustainability all aquifers, but improving qualitative sustainability is possible only in three aquifers. [ABSTRACT FROM AUTHOR]

In this paper, a finite fractured aquifer, bounded by a stream and impervious layers on the other sides, has been considered. Variation in the level of groundwater is analyzed in confined aquifer for the unsteady flow. The governing differential equation for piezometric head involves the Caputo–Fabrizio fractional derivative operator with respect to time and is based on dual-porosity model with the assumption that the flow from fracture to block is in pseudo steady state. The obtained solutions can be used to anticipate the fluctuations in the waterlevels of the confined aquifer and for the numerical validation of a model in an aquifer. [ABSTRACT FROM AUTHOR]

Nitrate contaminant degrades groundwater quality and threatens the health of the humans, livestock, and the environment. Damaneh-Daran aquifer is located at upstream of the Zayandehrood reservoir in west-central Iran. This aquifer has been highly contaminated by nitrate and is still rapidly being contaminated. Thus, its quality needs to be remediated. This paper is focused on the quantity-quality modeling to predict the average nitrate concentration of the aquifer. Several remediation scenarios are presented in a period beginning from fall 2019, ending in spring 2024. These scenarios address several ways to mitigate the injection of the major sources of contamination in the region, such as equipping the urban regions with wastewater collection and treatment plants and reducing the fertilizers' use. The decreased use of the fertilizers may be achieved through two strategies: directly reducing the amount of the fertilizers by several specific and predefined rates of reduction and indirectly decreasing the amount of the fertilizers used by crop pattern modification. The latter strategy is evaluated to replace all or a part of the areas allocated to the more fertilizer-demanding crops with those of the less fertilizer-demanding crops. Furthermore, some of these scenarios are hybridized to more mitigate groundwater quality degradation. The results of performing the proposed scenarios are once compared together and then compared with the trend scenario letting current case study conditions and facilities be held in the future. The results suggest that the scenario hybridizing the effects of the wastewater treatment plants-equipping scenario with those of the quality-enhancing crop pattern modification scenario is evaluated as the most effective and best-performing scenario, implementation of which offers 20% and 30% reduction of the nitrate concentration for the agricultural and urban areas, respectively. [ABSTRACT FROM AUTHOR]

Groundwater flow modelling is an important tool in simulating and predicting hydraulic behaviour of groundwater transporting in the domain consisted of groundwater flow zone (aquifer) and permeable reactive barriers (PRBs). The aquifer regime is modelled using the Darcy equation, whereas PRBs are simulated by the Brinkman equation. By combining the above equations, the present paper is devoted to analyse the effect of permeability of aquifer ( K) and reactive media ( K), groundwater flow velocity, and barrier size as well as assembled style of barriers on key barrier design parameter, such as the hydraulic capture zone width. The simulations indicate that the capture zone width generally decreases with a decrease in K at a given K; however, there is relatively little decrease in capture zone width when the K of freshly installed reactive media is roughly 10 times higher than the K. For a given barrier system, the absolute capture zone width increases with an increase in barrier size, whereas the increment of relative capture zone width decreases dramatically. Although the capture zone width remains relatively unchanged as groundwater flow velocity increases, it results in a shorter residence time in the reactive media that may require greater barrier thickness so that contaminant levels can be reduced to regulatory limits. In addition, the effect of parallel barriers interaction on the capture zone width should be incorporated into the design. The present paper is based on the continuous reactive barrier and homogeneous barrier system. Similar methods can be used to analyse the hydrodynamics of funnel-and-gate system and heterogeneous settings by the appropriate modification. [ABSTRACT FROM AUTHOR]

One task facing by the geotechnical engineers is to protect the workspace in an underground construction/excavation site from various forms of geological disasters, such as the water inrush, rock burst, and collapse of the surrounding rock/soil. In this paper, a combined controlling measure was proposed based on underground mining and water environment: the method of strip mining has been initially proposed as an effective measure against underground workspace floor failure when mining above confined aquifer in the Bucun coal mine, China, and however, its ability to avoid floor water inrush has yet to be demonstrated; in the next step, field trials using caving zone backfill technology to prevent underground workspace floor failure and excavate retained strip coal pillars were implemented based on the theoretical calculation and numerical simulation results. Engineering practice showed that the failure depth of the underlying strata of the workspace had no growth without the possibility of water inrush, and the safety of the underground space was achieved. Thus, this study represents a successful attempt to develop the combined strip mining and caving zone backfilling technique to ensure the safety of the underground workspace and control surface subsidence when excavating the retained strip coal pillars above confined aquifer. The proposed combined technique can also be used in other underground excavation activities with similar problems. [ABSTRACT FROM AUTHOR]

This study addresses mechanical models of sinkhole formation and their criteria obtained via simulation test. Sinkholes are a common geohazard and are widely distributed throughout the world. Previous studies suggest that sinkhole formation is the result of complex interactions among geological conditions, with one or more factors triggering occurrence of sinkholes. We suggest that the existence of a void caused by soil loss is the premise of this issue. Therefore, we present soil loss is the mechanism of sinkhole formation in soils in this paper. Soil loss is caused by the interaction between groundwater and soils in nature. This interaction includes the groundwater condition and the characteristics of soils. In this study, we considered three types of groundwater conditions and two types of soils to discuss the mechanical model of sinkholes. There are three models of sinkhole formation in soils: the disintegration model in vadose zone, the seepage erosion model in unconfined aquifer, and the hydraulic fissures model in confined aquifer. A disintegration apparatus was designed to simulate the disintegration process and to obtain the criteria parameters of water content. Circular pipe flow equipment was designed to simulate the seepage erosion process to obtain the criteria parameter of groundwater velocity. The mechanical model of sinkholes in the confined aquifer was the hydraulic fissures model. The hydraulic equipment was designed to simulate the hydraulic fissure process to measure the criteria parameter of water pressure. [ABSTRACT FROM AUTHOR]

The hydrogeological conditions of the Qianbei coalfield are complex, and karst water in the roof rock frequently disrupts mining operations, leading to frequent water inrush incidents. Taking the representative Longfeng Coal Mine as a case study, research was conducted on the development pattern of the water-conducting fracture zone and the water inrush mechanisms beneath karst aquifers. On the basis of key stratum theory and calculations of the stratum stretching rate, the karst aquifer in the Changxing Formation was identified as the primary key stratum. It was deduced that the water-conducting fracture zone would develop into the karst aquifer, indicating a risk of roof water inrush at the working face. Numerical simulations were used to study the stress field, displacement field, and plastic zone distribution patterns in the overlying roof strata. Combined with similar simulation tests and digital speckle experiments, the spatiotemporal evolution characteristics of the water-conducting fracture zone were investigated. During the coal mining process, the water-conducting fracture zone will exhibit a "step-type" development characteristic, with the fracture morphology evolving from vertical to horizontal. Near the goaf boundary, the strain gradually decreases, and the instability of the primary key stratum significantly impacts the mining space below, leading to the closure of interlayer voids or the redistribution of water-conducting fissure patterns. Field measurements of the water-conducting fracture zone reveal that postmining roof fractures can be classified into tensile-shear, throughgoing, and discrete types, with decreasing water-conducting capacity in that order, the measured development height of the water-conducting fracture zone (51 m) aligns closely with the theoretical height (51.37 m) and the numerical simulation height (49.17 m). Finally, from the perspective of key stratum instability, the disaster mechanisms of dynamic water inrush and hydrostatic pressure water inrush beneath the karst aquifers in the northern Guizhou coalfield were revealed. The findings provide valuable insights for water prevention and control efforts in the Qianbei coalfield mining area. [ABSTRACT FROM AUTHOR]

In Iran, Behesht Abad Water Transfer from the headwaters of Karoon to the central plateau is one of the most critical inter-basin water transfer projects. This study aims to evaluate the impacts of the Water Transfer (WT) on the water level and flow of Farsan Aquifer in the origin basin. To achieve this goal, WEAP-GMS was used. Some defined scenarios include maximum water transfer from the origin to the destination basin in three modes of normal hydrologic, drought, and increasing environmental demand of the river. The maximum transferable water in a normal year is 450 and deceases to 160 MCM in a drought year. Also, the groundwater level before and after WT, the flow direction, the dry aquifer surface, and the dry wells were calculated. The results demonstrate that water transfer in the long term will cause a drop in the aquifer volume and level of the origin basin. Almost 34% of the aquifer surface and 138 wells will be thoroughly dried. Based on the results, inter-basin water transfer plans may solve the water shortage of the destination basin (recipients) over the short-term, but in long periods have adverse impacts on the environmental sustainability of the origin basin (donor). [ABSTRACT FROM AUTHOR]

This paper uses the homotopy perturbation method for the analytical solution of groundwater table fluctuations, in response to the tidal boundary condition, for a coastal unconfined aquifer with sloping beach face. The Boussinesq equation for sloping beach contains two non-linear terms. The governing equation is reconstructed in homotopic form with two virtual perturbation parameters and an auxiliary term. The secular terms generated from the non-linear diffusion term and the slope term are eliminated by using parameter expansions based on two virtual parameters. Two non-dimensional parameters emerge from the solution in the process of eliminating secular terms: (i) parameter equivalent to amplitude parameter and (ii) parameter representing beach slope. The second-order (starting from zeroth-order) solution is presented. The higher-order solution efficiently captures the non-linearity of the problem. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a new model of the distinct formation of groundwater of the aquifer system of the Northern Near-Caspian Region. The absence of sedimentary water displacement in plane is shown. An increase in mineralization and a wide range of characteristics of the composition and properties of rocks and waters are explained by processes of the mass-exchange in the water-rock system under conditions of low groundwater flow. The complex of the factors and conditions responsible for the integrity or displacement of sedimentary waters is determined, and it is suggested that it should be used to study the current and ancient sedimentary basins. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]

Monitoring groundwater level provides sufficient information on groundwater quantity and quality and is vital in effective management of water resources. This study applies transfer entropy coupled with directed-weighted complex network for the analysis of groundwater levels in the Sina river-basin, Maharashtra, India. All observation wells present in study area have been classified into five clusters using canopy clustering method. The direction and weight of the links of this complex network have been obtained by employing transfer entropy. Seasonal groundwater level data for pre-monsoon (May) and post-monsoon (October) were obtained from centre for groundwater board, Pune, Maharashtra for the period 1990–2009. Data analysis show that both pre-monsoon and post-monsoon groundwater level show significant decreasing trend. The proposed methodology determines the directional relationships between the selected observation wells of different clusters. It recognizes the most influenced well by using node strength and directed clustering coefficients. For each cluster, clustering coefficients and in-strength and out-strength have been calculated. Clustering coefficients for the selected wells of cluster 0 are 1, 1, 1, 0.6844 and 0.6342 which indicates Cluster 0 emerges as the strongest cluster. Similarly, clustering coefficients for cluster 4 are 0.6604, 0.6540, 0.3095, 0.2616 and 0 which means cluster 4 is the weakest among all the clusters formed. Clustering coefficients obtained for all clusters indicate that all wells within a cluster are forming clusters among themselves, however, some are strong whereas others are weak clusters. Therefore, transfer entropy can be effectively applied to groundwater and results obtained from it can be used for forecasting and water resources management. [ABSTRACT FROM AUTHOR]

The Peshawar Basin is a part of the lower Himalayas that contains an enormous amount of groundwater storage. The evaluation of groundwater potential in the southern Peshawar district was done using well logging, lithostratigraphic properties, and combined hydrogeological and geophysical techniques. A total of 13 Vertical Electrical Sounding (VES) profiles were utilised to assess potential groundwater zones for surface resistivity studies. The aquifer system was delineated by comparing the data from five boreholes with the VES findings. An exploration of super-saturated groundwater potential was conducted, utilising parameters such as transmissivity (T), hydraulic conductivity (K), storativity, and the Dar Zarrouk analysis. The Dar Zarrouk analysis yielded average values of transverse resistance (TR), longitudinal conductance (S), and anisotropy (λ), which were determined to be 8069.12, 0.51, and 0.561, respectively. Similarly, average values of transmissivity (T), hydraulic conductivity (K), and storativity were obtained, resulting in 28.67, 0.24, and 0.000177, respectively. The saturated confined layer, characterized by highly saturated zones, was identified to begin at a depth of approximately 119 m and extend down to the lower boundary of the aquifer. The examined aquifer is composed of clay, sand, gravel, boulders, and loose layers of lacustrine mud that are interlayered to form an unconsolidated groundwater aquifer system. The aquifers in the region are highly developed and consisted of unconfined, semi-confined, and confined aquifer systems. As a result, it is possible to use the aquifer for groundwater development in the study area because of its low -to-medium discharge. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Engineering Geology & the Environment is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of Engineering Geology & the Environment is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper presents the results of aluminium determinations in ground water samples of the Miocene aquifer from the area of the city of Poznań (Poland). The determined aluminium content amounted from <0.0001 to 752.7 $\upmu $g L. The aluminium determinations were performed using three analytical techniques: graphite furnace atomic absorption spectrometry (GF-AAS), inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). The results of aluminium determinations in groundwater samples for particular analytical techniques were compared. The results were used to identify the ascent of ground water from the Mesozoic aquifer to the Miocene aquifer in the area of the fault graben. Using the Mineql+ program, the modelling of the occurrence of aluminium and the following aluminium complexes: hydroxy, with fluorides and sulphates was performed. The paper presents the results of aluminium determinations in ground water using different analytical techniques as well as the chemical modelling in the Mineql+ program, which was performed for the first time and which enabled the identification of aluminium complexes in the investigated samples. The study confirms the occurrence of aluminium hydroxy complexes and aluminium fluoride complexes in the analysed groundwater samples. Despite the dominance of sulphates and organic matter in the sample, major participation of the complexes with these ligands was not stated based on the modelling. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Engineering Geology & the Environment is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract  As monitoring wells (MWs) in clay layers have a time lag of weeks or months, the piezometric level (PL) at a given time is difficult to assess. For time lag problems due to external loadings, Hvorslev provided solutions depending on the clay saturated hydraulic conductivity, k, but not on its specific storage S s. This paper examines natural conditions rather than external loading and reports some practical examples using the finite element method. When the hydraulic heads in the upper and lower aquifers are initially constant and then change rapidly at the same time to take new constant values, the time lag is shown to depend on both k and S s and the MW gives the correct PL after several weeks. This time lag largely exceeds that obtained following Hvorslev. When the aquifer heads vary with time, which is the usual case, the water level in the pipe is never a PL and any extrapolation of water level versus time gives an unreliable prediction of the PL. [ABSTRACT FROM AUTHOR]

Safeguarding groundwater from civil, agricultural and industrial contamination is matter of great interest in water resource management. During recent years, much legislation has been produced stating the importance of groundwater as a source for drinking water supplies, underlining its vulnerability and defining the required quality standards. Thus, schematic tools, able to characterise the quality and quantity of groundwater systems, are of very great interest in any territorial planning and/or water resource management activity. This paper proposes a groundwater quality classification method which has been applied to a real aquifer, starting from several studies published by the Italian National Hydrogeologic Catastrophe Defence Group (GNDCI). The methodology is based on the concentration values of several parameters used as indexes of the natural hydro-chemical water condition and of potential man-induced modifications of groundwater quality. The resulting maps, although representative of the quality, do not include any information on its evolution in time. In this paper, this “stationary” classification method has been improved by crossing the quality classes with three indexes of temporal behaviour during recent years. It was then applied to data from monitoring campaigns, performed in spring and autumn, from 1990 to 1996, in the plain of Modena aquifer (central Italy). The results are reported in the form of space-time classification table and maps. [ABSTRACT FROM AUTHOR]

An improved produced water reinjection (PWRI) model that incorporates filtration, geochemical reaction, molecular transport, and mass adsorption kinetics was developed to predict cake deposition and injectivity performance in hydrocarbon aquifers in Nigeria oil fields. Thus, the improved PWRI model considered contributions of geochemical reaction, adsorption kinetics, and hydrodynamic molecular dispersion mechanism to alter the injectivity and deposition of suspended solids on aquifer wall resulting in cake formation in pores during PWRI and transport of active constituents in hydrocarbon reservoirs. The injectivity decline and cake deposition for specific case studies of hydrocarbon aquifers in Nigeria oil fields were characterized with respect to its well geometry, lithology, and calibrations data and simulated in COMSOL multiphysics software environment. The PWRI model was validated by comparisons to assessments of previous field studies based on data and results supplied by operator and regulator. The results of simulation showed that PWRI performance was altered because of temporal variations and declinations of permeability, injectivity, and cake precipitation, which were observed to be dependent on active adsorption and geochemical reaction kinetics coupled with filtration scheme and molecular dispersion. From the observed results and findings, transition time t to cake nucleation and growth were dependent on aquifer constituents, well capacity, filtration coefficients, particle-to-grain size ratio, water quality, and more importantly, particle-to-grain adsorption kinetics. Thus, the results showed that injectivity decline and permeability damage were direct contributions of geochemical reaction, hydrodynamic molecular diffusion, and adsorption kinetics to the internal filtration mechanism, which are largely dependent on the initial conditions of concentration of active constituents of produced water and aquifer capacity. [ABSTRACT FROM AUTHOR]

Various studies have described upon importance of the performance of multilevel slug tests to assess hydraulic conductivity of aquifer sediment. For this study, slug tests were performed at 33 locations in 107 numbers of observation wells under six physiographic divisions in the Bengal Basin, Bangladesh. The objective of this paper is to evaluate the potential of multilevel slug tests to determine depth distribution and vertical variations of hydraulic conductivity in layered aquifer systems of the Bengal Basin that can be utilized for resource assessment. The studied aquifer sediments are dominated by unconsolidated fine and very fine sand with lenses of clay and silty clay aquitards. The hydraulic conductivity values commonly correspond with the lithology and their settlements. The unconsolidated sand in the Active and Tidal Delta contains high hydraulic conductivity values of up to 24.4 m/day. Older sediments in the Teppera Surface and Coastal Plain show lower average hydraulic conductivity. Very low hydraulic conductivities in few wells indicate the heterogeneities as well as poor development of these newly installed wells. Individual layers have relatively uniform grain size with well sorted sands, and their hydraulic conductivity values have a small variation, while sediments from multiple layers have variations in grain size with anisotropic signature and their hydraulic conductivity values, in many cases, vary by orders of magnitude. However, multilevel slug tests can provide considerable information about vertical variations in hydraulic conductivity under the right conditions. Although the slug tests were performed with precaution, unknown uncertainties in the well during the operation may influence the values of hydraulic conductivity. A more accurate values of the conductivity variations can be achieved by placing thin, low-conductivity layers in the sand pack that reduces vertical flow. Selection of drilling procedure and the techniques of measurement and analysis are also important to get good results. Factors like leakage and partial penetration should also be minimal for optimum results [ABSTRACT FROM AUTHOR]

Alluvial aquifers often exhibit highly conductive embedded formations that can act as preferential pathways for the transport of solutes. In this context, a detailed subsurface characterization becomes crucial for an effective monitoring of groundwater quality and early detection of contaminants. However, small-scale heterogeneities are seldom detected by traditional nondestructive investigations. Heat propagation in porous media can be a relatively inexpensive tracer for groundwater flow, potentially offering valuable information in various applications. In this study, we applied passive Fiber Optics Distributed Temperature Sensing (FO-DTS) to a group of observation wells in a highly heterogeneous phreatic aquifer to uncover structures with different hydraulic conductivity, relying on their response to temperature fluctuations triggered by natural and anthropogenic forcings. A comprehensive data analysis approach, combining statistical methods and physics-based numerical modeling, allowed for a three-dimensional characterization of the subsurface at the experimental site with unprecedentedly high resolution. [ABSTRACT FROM AUTHOR]

Water is one of the most imperative needs and used for innumerable purpose. The needs of groundwater exploration have being increased due to the radical climatic changes, for continually increased population growth and a change of human lifestyle. GIS and AHP of multicriteria decision making are the most effective, applicable and logical approaches to delineate the groundwater potential zones in upper parts of Chemoga watershed. GIS and AHP are a 7 computer-based systems used to handle, store, manipulate, analyze and present geospatial data to resolve several complicated problems in the environment. Hence, the groundwater potential zone is delineated by overlaying the weights of ten influencing factors (lineament density, rainfall, geomorphology, Lithology, slope, drainage density, roughness, land use/land cover, depth to groundwater level and elevation) in ArcGIS platform under spatial analysis tool. All those influencing factors are selected on the bases of their contribution for the ground water recharge. Based on the findings of weighted overlay analysis, 11.1, 18.2, 47.1, 15.4 and 8.2% of the region depicted very good, good, moderately good, poor, very poor groundwater potential zones, respectively. The investigated groundwater potential sites have validated by seven existed borehole data and hence the study verified their close relationships. Out of seven boreholes, about 7–4 and 3–1 were found under very good to good and poor to very poor groundwater potential zones, respectively. [ABSTRACT FROM AUTHOR]

Data from pumping tests is a noisy process, and therefore, performing the pumping test numerous times will not get the same drawdown values. As a consequence, various pumping experiments lead to different values for aquifer parameter estimates. The data of pumping tests are usually analyzed using traditional methods (aquifer tests and AQtesolv software), which depend on trial and error technique. During these methods, non-unique values of hydraulic parameters are selected, which usually have a high level of uncertainty. Uncertainty must be taken into account in determining aquifer parameters, especially when using groundwater models for decision makers. The main goal of this study is to build a comprehensive tool for quantifying uncertainty associated with hydraulic parameter estimation from different pumping test conditions for fully penetrating wells in confined and semi-confined aquifers. To achieve the previous objective, a FORTRAN code was developed to apply the Markov Chain Monte Carlo (MCMC) algorithm using different likelihood functions (exponential, inverse, and log). This developed tool can be used to detect the most probable range of aquifer parameters that are consistent with pumping test data with a high degree of confidence. The tool was successfully used to several hypothetical cases to demonstrate the uncertainty in the quantification of aquifer parameters and compare the findings to the standard method's results. Also, the concept was verified numerically (using Modflow program) with satisfactory results using a hypothetical case with well-known aquifer parameters. Finally, the tool was applied for actual pumping test data with good results. [ABSTRACT FROM AUTHOR]

The construction of the New Galala City besides great mining (e.g., konoozmisr) and Seawater Reverse Osmosis Desalination Plant projects in the semiarid Gulf of Suez region of Egypt increases the demand for groundwater resources. So, the current research provides integrated stratigraphical, hydrogeochemical, and geophysical studies to investigate the shallow groundwater aquifers in Wadi Araba area on the western side of the Gulf of Suez. The stratigraphic column starts with pre-Cambrian basement rocks which are non-conformably overlain by sedimentary succession of Phanerozoic Erathem. A detailed land magnetic profile has been conducted and processed to estimate the aquifer's geometrical parameters. This includes the subsurface spatial extension and thickness to delineate the prevailed subsurface structures in the study area. Lithostratigraphically, these aquifers are represented by the Paleozoic- lower Cretaceous siliciclastic-dominated sediments of the Nubia Group and fractured carbonate-dominated facies of the upper Cretaceous Galala Formation. Lithological characters, sedimentary facies (fluvial to shallow and open marine), microfacies types, and diagenesis processes (e.g., compaction, cementation, dissolution, and fracturing) are the main factors that affect the quality of the shallow aquifers in the study area. The main microfacies of the studied aquifers are quartz arenite, subarkose, sublitharenite, mudstone/wackestone, and packstone/grainstone. These facies are characterized by different primary and secondary porosities. According to the water sampling standard methods, nineteen groundwater samples were collected from the available hand-dug wells and springs from the Nubian sandstone aquifer and the Upper Cretaceous aquifer, respectively. Inductively coupled plasma–mass spectrometry (ICP–MS), titration, spectrophotometer and a flame photometer were used to obtain a complete chemical analysis. The results of hydrochemical analyses indicated that total dissolved solids (TDS) and concentrations of major ions as well in the lower Cretaceous aquifer increase toward the Gulf of Suez and in general higher than that of springs of the Upper Cretaceous Aquifer. The predominant factors influencing groundwater chemistry include seawater intrusion, evaporation, mineral alteration, dissolution of fossils, and ion exchange. Groundwater in the study area is unsuitable for drinking except in one sample and moderately suitable for irrigation with caution for higher salinity in samples located near the Gulf of Suez. [ABSTRACT FROM AUTHOR]

The Ningdong coalfield has played a pivotal role in advancing local economic development and meeting national energy. Nevertheless, mining operations have engendered ecological challenges encompassing subterranean water depletion, land desertification, and ground subsidence, primarily stemming from the disruption of coal seam roof strata. Consequently, the local ecosystem has incurred substantial harm. Water-preserved coal mining presently constitutes the pivotal technology in mitigating this problem. The primary challenge of this technique lies in identifying critical aquifer layers and understanding the heights of water-conducting fracture zones. To obtain a precise comprehension of the seepage patterns within the upper coal seam aquifer during mining, delineate the extent of water-conducting fracture zones, non-invasive geophysical techniques such as time-lapse electrical resistivity tomography (TL-ERT), magnetic resonance sounding (MRS), and spontaneous potential (SP) have been employed to monitor alterations within the shallow coalfield's aquifer throughout the mining process in the Ningdong coalfield. By conducting meticulous examinations of fluctuations in resistivity, moisture content, and self-potential within the superjacent strata during coal seam extraction, the predominant underground water infiltration strata were ascertained, concurrently enabling the estimation of the development elevation of water-conducting fracture zones. This outcome furnishes a geophysical underpinning for endeavors concerning local water-preserved coal mining and ecological rehabilitation. [ABSTRACT FROM AUTHOR]