Fresh Groundwater Research Articles

Engineering-geological zoning of the central area of the Upper Kama Potassium–Magnesium Deposit in view of salt karst propagation

With a view to geological and environmental safety of the central area of the Upper Kama Potassium–Magnesium Salt Deposit, the engineering-geological zoning is performed to identify karst-sensitive land. The zoning is based on two most fundamental factors: hydrogeology and neotectonics. Evaluation of the first factor consisted in determining the thicknesses of suprasalt deposits and the size of fresh groundwater zone by analyzing the data of exploration wells and other geological and hydrogeological materials, as well as calculating the thickness of the separating stratum corresponding to the interval of deposits from the top of the salt stratum to the lower boundary of the zone of fresh groundwater. The analysis of the second, neotectonic, factor was associated with the identification of increased fracturing zones in rock mass based on the grouping of faults and lineaments obtained from the interpretation of cosmic and aerial photographs, as well as from the construction and analysis of digital elevation models during field route observations. The comparison of two factors made it possible to zone the territory of research into areas with different degrees of protection of the salt stratum from the potential development of karst: high, medium and low. Within the areas with a low degree of protection, the further detailed studies of the hydrodynamic regime of groundwater and their interaction with the host rocks are necessary. The described method of engineering-geological zoning can find application to provide natural and technological safety in underground mining areas. The results obtained can be used in design of systems of special-purpose geodetic and hydrogeological monitoring.The research was carried out under the state contract, Topic No. AAAA-A19-119021190076-9.

Geometry of the modelled freshwater/salt-water interface under variable-density-driven flow (P\xe9trola Lake, SE Spain)

Pétrola Lake in southeast Spain is one of the most representative examples of hypersaline wetlands in southern Europe. The rich ecosystem and environmental importance of this lake are closely associated with the hydrogeological behaviour of the system. The wetland is fed by the underlying aquifer with relatively fresh groundwater—1 g L−1 of total dissolved solids (TDS)—with a centripetal direction towards the wetland. In addition, the high evaporation rates of the region promote an increase in the concentration of salts in the lake water, occasionally higher than 80 g L−1 TDS. The density difference between the superficial lake water and the regional groundwater can reach up to 0.25 g cm−3, causing gravitational instability and density-driven flow (DDF) under the lake bottom. The objective of this study was to gain an understanding of the geometry of the freshwater–saltwater interface by means of two-dimensional mathematical modelling and geophysical-resistivity-profile surveys. The magnitude and direction of mixed convective flows, generated by DDF, support the hypothesis that the autochthonous reactive organic matter produced in the lake by biomass can be transported effectively towards the freshwater–saltwater interface areas (e.g. springs in the lake edge), where previous research described biogeochemical processes of natural attenuation of nitrate pollution.

Saltwater intrusion management in shallow and deep coastal aquifers for high aridity regions

Study regionThe current study was applied on two extensive and important regional aquifers: the first is the shallow aquifer of Gaza coastal aquifer (GCA), Palestine and the second is the deep aquifer of the Nile Delta (NDA), Egypt. The two sites are suffering from high stress water resource and contamination by saltwater intrusion (SWI). SWI is natural phenomena that damage the fresh groundwater in two sites and increase the aquifer. Shallow and deep aquifer plays a natural role for keeping the quality of freshwater from SWI in costal aquifers. This study aims to compare different methods for aquifer protection from SWI by analyzing their efficiency using numerical groundwater models in the two sites. Study focusThe finite difference for density dependent groundwater flow model SEAWAT was used on two sites to investigate the extension of SWI without management (base case) and the four methods to control SWI. The numerical models were calibrated for the base case using the other studies and field data to simulate the intrusion in GCA and NDA. The investigated four methods focused on (1) subsurface physical barriers of Cut-off walls), (2) subsurface physical barriers of subsurface dams, (3) the hydraulic method including Treatment and Recharge of collected wastewater, Abstraction and Desalination of low salinity by brackish water, and (4) the land reclamation using earth fill method. New hydrological insights for the regionThe simulated results indicated for the base cases that the intrusion salt mass (NaCl) reached 6068 × 103 kg for GCA and 8863 × 1010 kg for NDA. Moreover, the percentage of aquifer salt mass was decreased and reached 17.60%;, 23.30%; 7.85% and 6.20% in for shallow aquifer while it reached 2.05%; 0.90%; 5.30% and 0.80% in deep aquifer for the physical subsurface dam of cut-off wall, subsurface dam, hydraulic method and land reclamation technique respectively. On the other side the control methods in shallow aquifers is more effective than the deep one. The subsurface barriers and land fill method isn’t effective for deep aquifer while the hydraulic of TRAD method has a positive effect on SWI in shallow and deep aquifers. The current study could be carried out around the world in different coastal hydrological groundwater thickness using the effective method to increase the mitigation of SWI and increase the fresh groundwater resources in coastal aquifers.

Climate Change Impacts on Agricultural Water Availability in the Middle Rio Grande Basin

AbstractWe present a comprehensive analysis of water availability under plausible future climate conditions in a heavily irrigated agricultural watershed located in the middle section of the Rio Grande Basin in the United States Desert Southwest. Future managed streamflow scenarios (through year 2099) were selected from among 97 scenarios developed based on downscaled, bias‐corrected global climate model outputs to evaluate future inflows to the principal surface water storage reservoirs, possible future reservoir releases, and groundwater pumping to sustain irrigated agriculture. The streamflow projections describe a wide range of dry and wet conditions compared to the average historical flows in the river, indicating significant uncertainty in future water availability in the Rio Grande Basin. We applied the Soil and Water Assessment Tool to illustrate the impact of climate futures on different components of the water budget at a watershed scale. Results indicate declining reliability of reservoir storage to meet the water demand of irrigated agriculture. The impact of declining surface water can be offset by increasing the pressure on the already‐strained groundwater resources. However, the region should be prepared to use slightly saline (total dissolved solids [TDS] > 1,000 mg/L) and moderately saline groundwater (TDS > 3,000 mg/L) as fresh groundwater in the regional aquifer is depleted within the 21st Century under hotter and drier conditions and status quo agricultural land and water management practices.

Identifying the Major Hydrogeochemical Factors Governing Groundwater Chemistry in the Coastal Aquifers of Southwest Bangladesh Using Statistical Analysis

People in the southwestern (SW) coastal part of Bangladesh are suffering from a severe freshwater crisis due to saline groundwater at a shallow depth. Fresh groundwater below a 200 m depth is an option, but it is costly to construct deep tubewells for the local inhabitants. The processes of salinization and freshening were previously identified using conventional methods. In this study, we brought new insight into these processes by analyzing existing datasets using multivariate statistics to identify the factors affecting groundwater chemistry. Cluster analysis (CA) revealed three major clusters. Cluster A corresponded to saline (NaCl-type) water. Cluster B was also saline (NaCl-type) water but showed mixing effects. Cluster C was fresh groundwater (NaHCO3-type) and isolated. The hydrochemical characteristics of clusters A, B and C compared remarkably well with the groundwaters from the upper shallow aquifer (USA), lower shallow aquifer (LSA) and deep aquifer (DA), respectively. Factor analysis (FA) showed that 75% of the total variance was influenced by evaporate dissolution, carbonate dissolution/precipitation, cation exchange and anthropogenic pollution to some extent. Therefore, the integrated approach showed the validity of applying multivariate statistical techniques to infer the dominant hydrochemistry and to characterize and understand a complicated hydrogeological system.

Groundwater Vulnerability Zones Mapping Using DRASTIC and GOD Methods in Krendowahono Village, Karanganyar Regency

Krendowahono Village is located in Karanganyar Regency, Central Java, Indonesia. During the dry season, several hamlets in Krendowahono Village experience a shortage of clean water. So an attempt must be made to maintain the quality and protect groundwater sources in areas of Krendowahono Village with fresh groundwater supplies. Analysing the vulnerability of groundwater is one of the attempts that can be made. The DRASTIC and GOD methods were used to conduct a vulnerability analysis of groundwater. The DRASTIC and GOD vulnerability assessments were then validated using water samples taken from resident wells. Groundwater vulnerability assessment utilizing the DRASTIC method resulted in the identification of two vulnerability classes: low vulnerability and medium vulnerability. While the GOD method generates three vulnerability classes for groundwater, they are low vulnerability class, medium vulnerability class, and high vulnerability class. The maximum correlation value between the results of the GOD method and the test of water samples with parameters of free ammonia, total dissolved solids (TDS), and salinity was obtained when the results of the GOD method and the test of water samples were validated using Spearman’s correlation. The correlation value associated with the pH parameter was the highest in the DRASTIC method. Likewise, the GOD method produced favourable performance in regional studies. This is demonstrated by the significant correlation between the GOD susceptibility test findings and the water sample test results.

Hydrochemical-geophysical study of saline paleo-water contamination in alluvial aquifers

An integrated hydrochemical and geophysical study of the saline paleo-water uprising into the alluvial aquifer of the Oltrepò Pavese plain sector (Po Plain, northern Italy) is presented. This study involved hydrochemical analysis of groundwater, assessment of well logs, and one-, two- and three-dimensional electrical geophysical surveys. The studied area was selected for its characteristic hydrogeological setting. The alluvial aquifer is strongly conditioned by the presence of a buried tectonic discontinuity along which the saline waters are mainly distributed. These waters rise along the discontinuities in the bedrock and flow into the overlying alluvial aquifer. Contamination from saline waters is not spatially and vertically homogeneous within the aquifer. The spatial distribution of Na–Cl waters suggests the existence of plumes of highly mineralized waters that locally reach the aquifer, diffuse and mix with freshwaters. The saline waters show a dilution during upward migration, which is due to mixing with the shallow fresh groundwater. Highly mineralized groundwater is identified even at very shallow depth in correspondence with each plume. On the other hand, there is a lower degree of contamination in those sectors of the aquifer that are further away from the structural discontinuities and this lesser contamination generally only involves the deeper parts of the aquifer.

Saline Water Impact on Water Use Efficiency of Bitter Melon (Momordica charantia L) Using Drip Irrigation

Water shortage is a real problem in many parts of the world and finding alternative solutions such as the application of saline water in cropping systems is highly appreciated. Research on drip irrigation and soil salinity is still inadequate, and their effect on crop yield and water use efficiency (WUE) is a huge challenge for small farmers. The present study was conducted in Malir, a semiarid region in the Sindh province of Pakistan. The purpose was to estimate the effects of two different qualities of irrigation water including fresh quality water (IT1 0.56 dS m−1) and saline groundwater (IT2 2.89 dS m−1) on WUE using drip irrigation technology in 2018–19. The experimental design was complete randomized block design (RCBD) with two treatments of irrigation: (1) freshwater (IT1) with 0.56 dS m−1 electrical conductivity and (2) saline water (IT2) with 2.89 dS m−1 electrical conductivity. The average biomass and crop yield under IT1 were 10.2 t.ha−1 and 7.4 t.ha−1, respectively, and were found higher than those under IT2 (7.3 t−1 and 4.2 t.ha−1, respectively). Hence, both the treatments remained equally effective in season 1 as compared to season 2 ( p ≤ 0.05 ). The WUE of bitter melon under IT1 was 1.60 and 1.56 kg.m−3 in seasons 1 and 2, respectively, and was higher than those under IT2 which were observed 1.21 and 1.07 kg.m−3 in seasons 1 and 2, respectively.

Aluminium fumarate-based polymer matrix composite for selective removal of fluoride from groundwater

Aluminium fumarate (AlFu) metal–organic framework (MOF) shows high fluoride adsorption from water, compared to other MOFs (Zr-MOFs, fumaric acid based MOFs), alumina-based porous materials, hydrated cement, waste mud etc. However, the nano-sized AlFu MOF tends to agglomerate in water. Thus, it reduces the fluoride removal efficiency of the MOF. Further, the exhausted MOF is difficult to regenerate and reuse. The present study prepared polymer matrix composite (PMC) to resolve it using an integrated chitosan mix coated on top of nanofiber (polyvinyl alcohol) support. Some of the PMC studied includes Ca-Zr @ polyvinyl alcohol (PVA), Fe-Al-Mn nanoparticles @ chitosan, and monetite bundles @ chitosan. AlFu MOF based PMC (9 g) was packed in a pouch-like tea bag and dipped in groundwater (1 L) with 10–30 mg fluoride/L. After 100 ± 10 min, the fluoride concentration was reduced to 1–1.5 mg/L. The exhausted PMC pouch could be regenerated by dipping it in 100 mL of treated water, tap water or deionized water for 5 h respectively. The same process was repeated ten times in fresh groundwater. Thus, PMC pouch could be used in our daily life.

Aeromonas Species in Meat Samples Obtained From Some Markets in Parts of Plateau State, Nigeria

Aeromonas species are emerging food borne pathogens with serious potentials for causing food borne diseases. They are estuarine bacteria and are ubiquitous in fresh water, ground water, bottled water, meats and fresh vegetables. A total of 800 meat samples, comprising of 4 different meat types; Chicken (200), beef (200), Fish (200) and chevon (goat meat) (200) were collected in the period of one year (from June 2017—June 2018) in Jos, Miango, Bukuru, Vom and Lamingo areas of Plateau state. These meat samples were analyzed for the presence of Aeromonas species using Aeromonas Dextrin agar and MacConkey agar. Overall 114 meat samples out of the 800 samples analyzed were positive for Aeromonas species with the beef having the highest percentage prevalence of 9.25% while the chevon had the lowest percentage prevalence of 5.75%. The result of this study revealed the presence of potentially pathogenic Aeromonas species in the meat samples obtained from these locations.

Reductive Dechlorination of Trichloroethene by Sulfided Microscale Zero-Valent Iron in Fresh and Saline Groundwater: Reactivity, Pathways, Mechanism and Selectivity

Reductive Dechlorination of Trichloroethene by Sulfided Microscale Zero-Valent Iron in Fresh and Saline Groundwater: Reactivity, Pathways, Mechanism and Selectivity

Challenges for groundwater-irrigated agriculture and management opportunities in Punjab province of Pakistan

Pakistan has one of the world’s largest contiguous irrigation canal networks which was initiated by the British during the early nineteenth century, and its continuous expansion significantly altered the hydrological balance of the Indus River Basin (IRB) in Pakistan. During the pre-irrigation era, the water table in the IRB was very deep which rose up with the introduction of canal network. Seepage from the earthen canals caused the dual menace of waterlogging and salinity and different Salinity Control and Reclamation Projects (SCARPs) were implemented. With the growing food and fiber requirements, use of groundwater increased over the time. Currently, in Punjab province groundwater is contributing about 45-50% towards irrigation through 1.2 million tube-wells, putting the aquifer under stress. As water table deepens, the cost of extraction increases. Besides its use for irrigation, groundwater is used for drinking, industrial and commercial requirements. In many areas, the unplanned and over-pumping has caused intrusion of saline water into fresh groundwater areas. This paper describes the historical development and current challenges for sustainable use and management of groundwater. Some initiatives by the Government are described, with available opportunities. A new research project that considers the potential of artificial aquifer recharge as part of the management has also been discussed.

Integral assessment of the geodynamic conditions for the formation of the Black Sea basin and connection with the current regime of groundwater in its northwestern shelf

The paper has a multidisciplinary character connecting bathymetric, geophysical and geological information to innovatively reconstruct the geodynamic conditions of the Black Sea basin formation, their influence on the modern relief and groundwater regime within its northwestern shelf as a reference region. The major goal is the rationale of modern geodynamic settings for the Black Sea Basin against the back- ground of the processes of its closure under tangential compression conditions, as well as their relation- ship with the hydrogeological conditions of the shelf zone. As primary evidence, the author determined the spatial positions of the Constanta-Sinop and SubPontian Suture Zones, pinpointing absorption locations of the Earth's crust at subduction zones. The facts and arguments presented in this paper are well integrated into the scheme of the oncoming of the Pontides island arc to the Eurasian Plate and the gradual closure of the back-arc marginal Black Sea Basin with a crust of transitional-type crust. The specific feature of the study is an innovative approach to comprehensive analysis of data that are a result of geological and geophysical works within the Black Sea water area. In doing so, major attention is paid to the spatial morphostructural analysis and interpretation of newly integrated digital data array, as a result of bathymetric surveys, namely the EMODnet 2019—2022. The subject of analysis is the basic structural surfaces, including the Modern and on its margin consolidated basement. New justification is formulated on the confinement of gas seeps and mud volcanoes, within the Black Sea Basin, to the deep earth`s crust structures. The graphical correlation of the mentioned ones is performed as well as their spatial position in the structural-geodynamic model of the region is theoretically substantiated. A generalized geomorphological zoning of the northwestern shelf of the Black Sea with the identification of the Dobrogea, Odesa and Kalamit zone is proposed. Within the Odesa geomorphological region, an integrated geological and geomorphological analysis was carried out and, as a result, dividing the shelf into submarine groundwater discharge (SGD) zone of aquifer was substantiated. The study, carried out by the author is of crucial importance to understanding the tectonic and geo- dynamic characteristics of the Black Sea Basin as well as for forecasting SGD zones and fresh groundwater resources. It is recommended to set targeted prospecting works to assess fresh groundwater resources in order to meet the water needs of coastal communities.

Estimation of fresh groundwater reserves of the Ravnetskoye deposit for water supply to the city of Ishim

Estimation of fresh groundwater reserves of the Ravnetskoye deposit for water supply to the city of Ishim

Offshore fresh groundwater in coastal unconsolidated sediment systems as a potential fresh water source in the 21st century

Coastal areas worldwide are often densely populated and host regional agricultural and industrial hubs. Strict water quality requirements for agricultural, industrial and domestic use are regularly not satisfied by surface waters in coastal areas and consequently lead to over-exploitation of local fresh groundwater resources. Additional pressure by both climate change and population growth further intensifies the upcoming water stress and raise the urgency to search for new fresh water sources. In recent years, offshore fresh groundwater (OFG) reserves have been identified as such a potential water source. In this study, we quantify, for the first time, the global volume of OFG in unconsolidated coastal aquifers using numerical groundwater models. Our results confirm previously reported widespread presence of OFG along the global coastline. Furthermore, we find that these reserves are likely non-renewable resources mostly deposited during glacial periods when sea levels were substantially lower compared to current sea level. We estimate the total OFG volume in unconsolidated coastal aquifers to be approximately 1.06 ± 0.2 million km3, which is roughly three times more than estimated previously and about 10% of all terrestrial fresh groundwater. With extensive active and inactive offshore oil pumping present in areas of large OFG reserves, they could be considered for temporary fresh groundwater exploration as part of a transition to sustainable water use in coastal areas on the long run.

SOLVING THE BINARY CLASSIFICATION TASK FOR THE ASSESSING OF BELOVEZHSKAYA PUSHCHA GROUNDWATERS’ SENSITIVITY TO MODERN CLIMATIC VARIATIONS

The scientific ideas about the impact of climate changes in recent and coming decades on groundwater accumulated to the present date indicate the absence of a coordinated experts opinion on the sensitivity of groundwater to modern climate changes. The article proposes a method for the determining of the sensitivity of groundwater on the example of the protected area of Belovezhskaya Pushcha to modern climatic variations, justifies the sufficiency of successful verification and validation of the obtained results on its basis.
 Based on actual meteorological, hydrological and hydrogeological data characterizing changes in air temperature, precipitation, water and thermal regime on the territory of Belovezhskaya Pushcha, atmospheric cycling, modeling of the sensitivity of groundwater to modern climatic variations was carried out, the task of binary classification of the level regime of groundwater of the Glubonetsky and Kamenyuksky hydrogeological posts was solved.
 Objective and subjective uncertainties of estimates of the impact of long-term variations of climatic characteristics on groundwater are considered, the need to continue comprehensive interdisciplinary studies of the relationship between climate change and fresh groundwater is noted.

Spatial distribution and sources of nutrients at two coastal developments in South Kohala, Hawai'i

Nutrient sources to coastal waters with coral reefs are not well-characterized. This study documented spatial distributions of nutrients within coastal waters along two developments with coral reefs, and identified nutrient sources through nutrient mixing plots, δ15N measurements in macroalgal tissue, and NO3− stable isotope mixing models. Nutrients decreased from fresh groundwaters to offshore waters, with some surface waters higher in concentrations than benthic ones. Conservative and non-conservative mixing between fresh and ocean waters occurred, the latter suggestive of local nutrient sources and biological removal. δ15N in macroalgal tissue and NO3− concurred that fresh groundwater, ocean water, and fertilizers were dominant nutrient sources. Benthic salinity and NO3− + NO2− concentrations illustrated that submarine groundwater discharge delivered nutrients to reefs in pulses ranging from minutes to days. Information generated from this study is imperative for developing management actions to improve water quality and make coral reefs more resilient to stressors.

Peculiarities of performance of experimental filtering works in sites subsoil operated by single water intakes

The article discusses the methods used in the field experimental filtration work, which allow you to gain knowledge about the filtration properties and water abundance of rocks. The features of the experimental filtration work in the subsoil areas operated by single water intakes are shown. It is noted that these are small water bodies, both in terms of the number of water wells and the amount of actual water withdrawal. The article proposes to use short-term single pumpings as a field research method in the above-mentioned areas, according to the results of which it is possible to substantiate the amount of required water withdrawal and determine the calculated values of the water conductivity coefficient. As an example, the results of pumping are considered, obtained during the implementation of experimental filtration work at three single water intakes located within the Latitude Ob region. The results of the experimental filtration work served as the source material for calculating the reserves of fresh groundwater. Fresh groundwater reserves were calculated and approved for each site in the amount of 499 m3/day for category B.

Groundwater quality assessment for irrigation use in the Godavari Delta region of east coast India using IRWQI and GIS

Abstract The present work was carried out in the deltaic region of the river Godavari in coastal Andhra Pradesh of southern India to evaluate the status of groundwater quality for irrigation. Groundwater is predominantly used in these productive agricultural fields. Saline water intrusion in fresh groundwater aquifers, which is mainly due to the excess withdrawal of groundwater, was recorded in the study area. A total of 80 groundwater samples were analyzed for physical and chemical parameters using standard chemical procedures. The groundwater mainly represents Na+–Cl− type, which shows the mixing of fresh water with saline water. The high correlation between Na+–Cl− and Mg2+–HCO3− explained that the intermixing of aquifer waters and the leaching of secondary salts influenced the region. Evaporation-fractional crystallizations are the main processes in the groundwater of the study area. The irrigation water quality index was calculated using different quality indices including Na%, sodium adsorption ratio, residual sodium bicarbonate (RSBC), permeability index (PI), magnesium hazard (MH), Kelly's ratio (KR), and potential salinity (PS), Cl−:HCO3−, Mg2+:Ca2+ and Na+:Ca2+ to estimate the suitability of groundwater quality for irrigation. Spatial distribution maps were prepared using raster interpolation in GIS. The assessment revealed that the areas covering 67.6% of electrical conductivity, 100% of total dissolved solids, 57.5% of Na%, 21.3% of RSBC, 66.3% of PI, 16.3% of MH, 65% of KR, and, 100% of PS required severe to moderate restrictions. Overall, the groundwater in the study region showed potential salinity due to geogenic and anthropogenic activities, and thus it must be monitored for sustainable agriculture.

Shallow and deep submarine groundwater discharge to a tropical sea: Implications to coastal hydrodynamics and aquifer vulnerability

The groundwater of the coastal aquifers, the primary source of drinking water for the community around it, is under stress due to changing climatic conditions, extreme climate events, over-exploitation, and natural/anthropogenic interferences. To sustain coastal groundwater, it is essential to understand the hydrogeological control on the distribution of salinity and submarine groundwater discharge (SGD) in various spatial and temporal scales at different depths. This study is focused to delineate the SGD and salinity distribution for shallow surficial and deep aquifers by application of the hydrogeochemical and geophysical approach in an intertidal zone. The resistivity [Electrical Resistivity Tomography (ERT), Vertical Electrical Sounding (VES)] and Ground Penetrating Radar (GPR) data show surficial aquifers have (up to 1.5 m below ground level (m bgl)) have higher freshwater discharge at the post-monsoon season and recirculation of infiltrated brackish water with increasing offshore distances. The re-circulated seawater in distant offshore was also predominant for intermediate (>1.5 up to 100 m bgl) (brackish water-saturated) and deeper depths (>100 m bgl) (fresh groundwater), which is observed from the distinct resistivity contrasts from VES. The interaction process for all the depths with seawater has been induced by the coastal hydrodynamics, meteoric recharge, and fluctuation of groundwater levels. However, variations of resistivity and sounding data delineate that the groundwater resources underneath the shallow depth brackish water are physically vertically disconnected from the surficial aquifer, but spatial variation in sounding data shows the hydraulic connectivity, which would lead to a serious concern for fresh groundwater resources, where density-dependent transportation of solute is plausible, both vertically and horizontally.