Subterranean Aquifers Research Articles

Diversity and Distribution of Australian Stygobiont and Other Groundwater-Associated Amphipods (Crustacea: Malacostraca: Peracarida)

Numerous and diverse groundwater habitats suitable for sustaining aquatic invertebrate communities exist across Australia. These habitats include enclosed subterranean aquifer systems, fractured rock, alluvial aquifers, perched aquifers, artesian springs, and spring-fed seeps and marshes. Crustaceans are a dominant member of these groundwater-associated invertebrate communities, and amphipods, both stygobiont and associated epigean species, are particularly diverse yet are still relatively poorly known. We review both the diversity and distributions of Australian amphipods associated with groundwater habitats, describing hotspots of diversity, providing notes on the unique Australian habitats, and examining the extraordinary species diversity and endemism of the Australian species. Our review highlights the significance of Australian groundwater ecosystems, their associated biodiversity, and the importance in considering these ecosystems in groundwater conservation management plans.

Groundwater quality assessment for drinking and irrigation purposes and its human health risks in the Sevathur mine region, south India

In this research, 35 samples of groundwater were collected and subjected to analysis with the aim of assessing its appropriateness for both drinking and irrigation purposes in Sevathur mine region, south India. Spatial depiction illustrates the widespread dispersal of primary positively charged ions and negatively charged ions formulated through the Inverse Distance Weighting (IDW) technique within a Geographic Information System (GIS). The Piper and Gibbs plots reveal a variety of water compositions in the surveyed region, encompassing combinations of mixed Ca-Mg-Cl, Ca-Mg-Cl-SO4, Na-K-Cl-SO4, and a few instances falling within the category of Ca-Mg-HCO3. The current features of hydrogeochemical facies result from the interplay between geological formations and water, alongside the occurrence of ion exchange, dissolution and weathering of calcium carbonate, calc-silicate minerals, and halite within subterranean aquifers. The water quality index unveiled that 23% of the samples fall into the poor category, while a substantial 11% are categorized as very poor. Additionally, 3% are undesirable, 17% are unfit for drinking, 23% exhibit a good, and 23% are distinguished by excellent categories. SAR values of subsurface water samples belong to the excellent class. Additionally, the RSC value indicates that 94% of the samples are categorized as suitable class, while 6% are classified as marginal for irrigation purposes. Individuals are advised to avoid drinking groundwater with fluoride levels above the WHO limit (>1.5mg/l), as 26% of samples exceeded this threshold. The region's groundwater chemistry is influenced by natural geological processes, such as mineral dissolution, and ion exchange, as well as human activities, including agricultural practices. Advanced water treatment techniques are being considered to improve water quality and ensure safer drinking water for the community.

Prospects of geothermal field development in Gandhar, Gujarat, India

Field development is an important part of natural resource utilization and exploration because it involves a systematic evaluation and optimization of a specific area. This study examines the geothermal field development in the Gandhar region of Gujarat, India. Gandhar for the past several decades has been a flourishing field for hydrocarbon extraction. However, as the world is dealing with environmental issues and the need to shift to cleaner and more sustainable energy sources, geothermal energy has emerged as a feasible and ecologically sound option. This study aims to understand the potential of regions in and around Gandhar as a prospective geothermal field of the west coast continental margin of India. Three primary disciplines namely geological, geochemical, and geophysical surveys are employed on the surface to assess the potential of Gandhar's geothermal resources. Geological assessments provide information about underlying geological formations, which might help to locate possible geothermal resources. The Deccan basement is a prominent source of magmatic heat, with a thermal gradient ranging from 1.29 to 1.87 W/K. This enhances Gandhar's geothermal potential by heating the underlying water in conjunction with radionuclides found in the Earth's core. The temperatures range from 60 to 80 °C according to Giggenbach triangle method. Gandhar's geothermal potential is further highlighted by the fact that its water is bicarbonate-rich, which connects it to possible subterranean aquifers. These results are verified by geophysical studies. Prospective geothermal reserves and four way closures can be found by as anomalies. Gravity survey reveal a doubly plunging antiform, with gravity high value of 5.4 and 5.3 mGa l respectively, which is corroborated by magnetic peaks of 58 and 56.2 nT Areas with higher conductivity are identified by resistivity studies, which also indicate possible fluid paths and geothermal reservoirs. The paper outlines a conceptual field development plan for the identified prospect. The basic infrastructure and the cost associated with it for field development is worked out. The cost of production/MWe of energy generation is also highlighted.

Beneath the Sea, Inland: Reading Aquifers and Opals in Australian Literature

ABSTRACT Deep beneath the surface of the continent, memories of the ancient Eromanga Sea are retained in subterranean aquifers and the veins of opal that flash above them in lithic fissures. The excavation of these hidden resources has been critical to the advancement of establishing the settler-colony, Australia, and in perpetuating the ongoing violence of Indigenous dispossession. In this paper, I examine the entangled subterranean figures of aquifers and opals as they surface in the Australian literary archive. I read early twentieth century representations of groundwater usage and opal mining communities in works by Banjo Paterson and Katharine Suzannah Prichard against contemporary evocations of these themes in novels by Janette Turner Hospital (Oyster) and Tara June Winch (Swallow the Air). In doing so, I explore the challenges of representing, reading and interpreting deep watery spaces.*

Predicting the alleviation of nitrate contamination in aquifers by conducting management scenarios using the PMWIN software: Application in the Andimeshk plain, Iran

Nitrate (NO3) is one of the most important contaminants of subterranean aquifers and has been stated as a worldwide concern. As available systems in Iran have failed to examine and control the quality of groundwater resources, the effective quality management of aquifers in the country is faced with many challenges. In this study, we implement management scenarios to predict the concentrations of NO3 introduction in the case study region. Firstly, NO3 was established as the main contaminant in the Andimeshk Plain (area of interest), then the quantitative model of NO3 contamination of the plain using PMWIN software was prepared, and finally, the temporal and spatial changes in the plain were investigated. Our findings showed that by reducing NO3 by around 25 and 50% in the agricultural zones, NO3 concentration drops about 2.11 and 11.87 mg/L per month, respectively. Moreover, the results of our study indicated that at a 50% NO3 decrease, the minimum and maximum concentrations of NO3 in Andimeshk Plain will be 9.48 and 38.51 mg/L, respectively, well below the actual concentrations (73.69 mg/L). Overall, we suggest that the methodology developed in this work can act as a primary step for the implementation of active NO3 reduction scenarios.

Assessment of Physico-Chemical Properties of Drinking Water in District Mardan, Khyber Pakhtunkhwa, Pakistan

The issue of water quality is becoming ever more serious as freshwater resources are severely degraded across the world. Water quality in rivers, streams, lakes, and subterranean aquifers is deteriorating, posing a threat to human life and ecological sustainability. A proper study of the physico-chemical properties of the water samples give us insight into the quality of life in a specific region, as poor water quality not only affects the aquatic life but the surrounding ecosystem as well. In the present study, 30 different water samples were collected from different regions of district Mardan and they were analyzed for their physico-chemical properties such as pH, total suspended solids, conductivity, total dissolved solids, nitrates concentration, sulphates concentration, chlorides concentration, dissolved oxygen, and biochemical oxygen demand. The results of the analysis show that most of the parameters have significantly higher values than the WHO permissible limits. From the analysis of water samples, the researchers have been able to designate the study area with poor water quality and to propose future advice for sustaining the water quality in the region.

Changes in the salt concentration distribution in surface water (seawater) due to seawater recirculation in a porous medium under tidal fluctuations

Many studies have used numerical simulations and experiments to simulate saltwater intrusion in a nearshore aquifer. Thus, it is known that seawater recirculation occurs in a porous medium just below a sloping beach, and a saltwater wedge occurs in the medium below where the slope intersects the water level at low tide. This study investigated the salt distribution in the surface water when subterranean recirculation of seawater is occurring and there is a saltwater wedge in an underlying porous medium, along with the relationships between the seawater recirculation and the tidal amplitude and beach gradient. The salt distribution in a subterranean aquifer and in surface seawater where the shore sloped gently seaward with a constant slope of 1/10 or 1/5 under tidal amplitudes of 0.5, 1.0, or 2.0 m was numerically simulated by the ASGMF method, which couples water pressure and water flow in a porous medium with those in the overlying surface water and can simulate variable-density flows and the salt concentration distribution in both the porous medium and the surface water. The results showed that the recirculation of seawater depended on the tidal amplitude, being greater when the amplitude exceeded 1.0 m, but that it was unlikely to occur when the beach gradient was steep. Thus, the aspect ratio (width to depth) of the seawater recirculation decreased as the tidal amplitude increased above 1.0 m. Furthermore, the simulated surface water level was often lower than the tidal water level; thus, the surface water level was not consistent with the tidal water level imposed at the right boundary of the simulation domain but varied slightly under the influence of water flow in the surface water and gas flow in the atmosphere. The salt concentration in the surface water was not always the same as the seawater salt concentration because a thin freshwater layer and a brackish water layer of mixed freshwater and saltwater overlay the seawater.

Lake Management and Eutrophication Mitigation: Coming down to Earth—In Situ Monitoring, Scientific Management and Well-Organized Collaboration Are Still Crucial

Lakes, together with rivers and subterranean aquifers, are indispensable natural resources for humans and other organisms [...]

Remote Sensing for Biocultural Heritage Preservation in an African Semi-Arid Region: A Case Study of Indigenous Wells in Northern Kenya and Southern Ethiopia

The region of Southern Ethiopia (Borana) and Northern Kenya (Marsabit) is characterised by erratic rainfall, limited surface water, aridity, and frequent droughts. An important adaptive response to these conditions, of uncertain antiquity, has been the hand-excavation of a sequence of deep wells at key locations often along seasonal riverbeds and valley bottoms where subterranean aquifers can be tapped. Sophisticated indigenous water management systems have developed to ensure equitable access to these critical water resources, and these are part of well-defined customary institutional leadership structures that govern the community giving rise to a distinctive form of biocultural heritage. These systems, and the wells themselves, are increasingly under threat, however, from climate change, demographic growth, and socio-economic development. To contribute to an assessment of the scale, distribution and intensity of these threats, this study aimed to evaluate the land-use land-cover (LULC) and precipitation changes in this semi-arid to arid landscape and their association with, and impact on, the preservation of traditional wells. Multitemporal Landsat 5, 7 and 8 satellite imagery covering the period 1990 to 2020, analysed at a temporal resolution of 10 years, was classified using supervised classification via the Random Forest machine learning method to extract the following classes: bare land, grassland, shrub land, open forest, closed forest, croplands, settlement and waterbodies. Change detection was then applied to identify and quantify changes through time and landscape degradation indices were generated using the Shannon Diversity Index fragmentation index within a 15 km buffer of each well cluster. The results indicated that land cover change was mostly driven by increasing anthropogenic changes with resultant reduction in natural land cover classes. Furthermore, increased fragmentation has occurred within most of the selected buffer distances of the well clusters. The main drivers of change that have directly or indirectly impacted land degradation and the preservation of indigenous water management systems were identified through an analysis of land cover changes in the last 30 years, supporting insights from previous focused group discussions with communities in Kenya and Ethiopia. Our approach showed that remote sensing methods can be used for the spatially explicit mapping of landscape structure around the wells, and ultimately towards assessment of the preservation status of the indigenous wells.

VULNERABILITY ANALYSIS OF UNDERGROUND AQUIFERS TO CONTAMINATION USING THE DRASTIC METHOD AND RISK DETERMINATION

Groundwater represents an important component in the supply of freshwater in several regions around the world. The contamination of these waters is a worrisome problem in the management of water resources. Since underground aquifers are vulnerable to contamination by human and industrial activities, including land use, the diagnosis associated with land use is critical for environmental management. The present study was carried out in the Uberaba sandstone formation, in which the vulnerability of the subterranean aquifers was determined using the DRASTIC method, by evaluating the interaction between the use and occupation of the land using a geographic information system. Thus, the risk of contamination of the underground aquifer was determined by evaluating the land use with the water quality and fertility. The tool applied in the present study proved effective for the diagnosis, management and action planning in the short and long term, with the intention of preserving these natural resources.

Undarobius, a new genus of cavernicolous weevils (Curculionidae: Entiminae: Leptopiini) from the Undara Lava Caves in north-eastern Australia, with an overview of anophthalmic and microphthalmic Australian Curculionidae.

Undarobius gen. n., a new genus of cavernicolous weevils with two new species, U. howarthi sp. n. and U. irvini sp. n., is described from the Undara Lava Cave system in north-eastern Queensland, Australia. These are the first cavernicolous weevils to be described from Australia, and U. howarthi is a new addition to the rich arthropod fauna of Bayliss Cave. Undarobius weevils are relatively large in size (4.05.5 mm long), anophthalmic and apterous with a robust, flattened body and long legs. The genus has affinities with Leptopiini, but its placement in the tribe is uncertain. We also provide a list of the known anophthalmic and microphthalmic weevils in Australia, spanning 65 species classified in 20 genera, eight tribes and about seven subfamilies and found in diverse hypogean habitats, mainly leaf litter but also soil, beach sand, subterranean aquifers and mosses.

Seasonally Variable Aquifer Discharge and Cooler Climate in Bermuda During the Last Interglacial Revealed by Subannual Clumped Isotope Analysis

AbstractFaunal analog reconstructions suggest that Last Interglacial (MIS 5e) sea surface temperatures were cooler around Bermuda and in the Caribbean than modern climate. Here we describe new and revised clumped isotope measurements of Cittarium pica fossil shells supporting previous findings of cooler than modern temperatures in Bermuda during the Last Interglacial. We resolve temperature and δ18Ow differences between two closely located and apparently coeval sites described in Winkelstern et al. (2017), https://doi.org/10.1002/2016pa003014 through reprocessing raw isotopic data with the updated Brand/IUPAC parameters. New subannual‐resolution clumped isotope data reveal large variations in δ18Ow out of phase with seasonal temperature changes (i.e., lower δ18Ow values in winter). Supported by modern δ18Ow measurements identifying similar processes occurring today, we suggest past variations in coastal δ18Ow were driven by seasonally variable freshwater discharge from a subterranean aquifer beneath the island. Taken together, our results emphasize the importance of δ18Ow in controlling carbonate δ18O, and suggest that typical assumptions of constant δ18Ow should be made cautiously in nearshore settings and can contribute to less accurate reconstructions of paleotemperature.

Sulfate Reduction in Underground Horizons of a Flooded Coal Mine in Kuzbass

Although dissimilatory sulfate reduction (DSR) is an important microbial process in subterranean aquifers, its geochemical consequences in this ecosystem remain insufficiently studied. The absence of data on the process rate under in situ conditions prevents quantitative estimation of the sulfur reservoir. This research is aimed at investigation of microbial sulfate reduction in subterranean aquifers associated with the Severnaya coal mine in Kuzbass. Water samples were collected from an artesian borehole broaching the underground horizons of the flooded mine. During over 10 years of sampling the water temperature fluctuated within a narrow range (10–13°C); the water was anoxic (–112 to –174 mV) and contained up to 6 mg/L sulfide. Analysis by high-throughput sequencing of the 16S rRNA genes showed that sulfur-oxidizing bacteria Sulfurovum, Sulfuricurvum, Sulfurospirillum, and Thiothrix predominated in the community. No phylotypes with known ability to carry out DSR were detected. Measurement of sulfate reduction rates with $${\text{Na}}_{{\text{2}}}^{{{\text{35}}}}{\text{S}}{{{\text{O}}}_{{\text{4}}}},$$ showed the process to be relatively active, resulting in up to 178 g of reduced sulfur per year at the borehole discharge. Two organisms representing minor components of the community, a psychrophilic and acidophilic Desulfomicrobium sp. DI and a moderately thermophilic Desulfotomaculum LL1, were isolated in pure culture by varying the cultivation condition in a bioreactor. These members of the “rare biosphere” may be responsible for production of reduced sulfur species, which are used by a diverse and numerous sulfur-oxidizing community.

A new record of Iranian subterranean fishes reveals the potential presence of a large freshwater aquifer in the Zagros Mountains

A new locality is reported for the Iranian subterranean fishes Garra typhlops and Garra lorestanensis (and probably Eidinemacheilus smithi), near the village Tuveh in the Dez River drainage. The site is 31 km straight-line distance away from the only other known locality where these species have been observed previously. The finding suggests the presence of a sizeable subterranean aquifer system in the Tigris drainage extending for between 31 and 162 km.

Voluminous territorialisation: Historical contestations over the Yucatan Peninsula’s subterranean waterscape

Over the past few years there has been a vertical-turn in human geographical scholarship with research, especially in the sub-fields of geopolitics and urban geography, increasingly focused in trying to understand space volumetrically: how subterranean and atmospheric spaces are entangled with surface socio-political dynamics. In this paper, we build on this work with a focus on the role of subterranean aquifers in volumetric geographies. We use the geopolitics of the northern Yucatan Peninsula in Mexico during the 1800s, as a case study to explore geographies of subterranean waterscapes and their implications for social-ecological processes. Specifically, we recast the Yucatan Peninsula’s relatively well-known history of henequen (an agave plant) production through a three-dimensional lens. Henequen in the Yucatan Peninsula became the key crop in producing rope and twine for international markets during the late 1800s and early 1900s, transforming the north of the Peninsula into one of the wealthiest regions in the world. We argue, that to fully appreciate the political economy dynamics of this boom, there is a need to rethink how the role of different technologies, economic regimes, and land control were affected by the interactions with the Peninsula’s subterranean aquifer. We conclude that the production of the henequen in the region of the Yucatan Peninsula was a three-dimensional form of control, and ultimately prosperity of the Spanish and their descendants in the region was heavily reliant on their ability to access, manage and shape human uses of the subterranean waterscape.

High Microbial Diversity Despite Extremely Low Biomass in a Deep Karst Aquifer

Despite the importance of karst aquifers as a source of drinking water, little is known about the role of microorganisms in maintaining the quality of this water. One of the limitations in exploring the microbiology of these environments is access, which is usually limited to wells and surface springs. In this study, we compared the microbiology of the Madison karst aquifer sampled via the potentiometric lakes of Wind Cave with surface sampling wells and a spring. Our data indicated that only the Streeter Well (STR), which is drilled into the same hydrogeologic domain as the Wind Cave Lakes (WCL), allowed access to water with the same low biomass (1.56–9.25 × 103 cells mL-1). Filtration of ∼300 L of water from both of these sites through a 0.2 μm filter allowed the collection of sufficient cells for DNA extraction, PCR amplification of 16S rRNA gene sequences, and identification through pyrosequencing. The results indicated that bacteria (with limited archaea and no detectable eukaryotic organisms) dominated both water samples; however, there were significant taxonomic differences in the bacterial populations of the samples. The STR sample was dominated by a single phylotype within the Gammaproteobacteria (Order Acidithiobacillales), which dramatically reduced the overall diversity and species richness of the population. In WCL, despite less organic carbon, the bacterial population was significantly more diverse, including significant contributions from the Gammaproteobacteria, Firmicutes, Chloroflexi, Actinobacteria, Planctomycetes, Fusobacter, and Omnitrophica phyla. Comparisons with similar oligotrophic environments suggest that karst aquifers have a greater species richness than comparable surface environs. These data also demonstrate that Wind Cave provides a unique opportunity to sample a deep, subterranean aquifer directly, and that the microbiology of such aquifers may be more complex than previously anticipated.

Education, fish consumption, well water, chicken coops, and cooking fires: Using biogeochemistry and ethnography to study exposure of children from Yucatan, Mexico to metals and arsenic

Around the world, the nocuous health effects of exposure to environmental contaminants, especially metals and Arsenic, are a growing health concern. This is especially the case in Mexico, where corruption and ineffective political administration are contributing to increasing deterioration in the environment. Importantly, shallow soils and the karstic nature of bedrock in Yucatan, Mexico make the subterranean aquifer especially susceptible to contamination because contaminates are carried to it with little resistance. Given these environmental conditions, we developed a multi/interdisciplinary project to evaluate the impact of metal and Arsenic pollution on a sample of 107 children, ages 6 to 9years, living in the urban areas of Progreso, Merida, and Ticul, in the State of Yucatan using urine and blood samples. In addition, ethnographic research was carried out in the homes of the children that participated in the study to identify potential exposure pathways. This research proved invaluable because the complexity of human social organization, lifestyles, and geographical patterning create an intricate array of exposure pathways that vary across social sectors and geographic space. In the following article, we use nonparametric univariate statistical analysis to reveal potential exposure pathways among sub-populations included in our sample. These analyses show that children from poor/marginal families tend to be exposed to Copper, Lead, and Nickel; whereas, children, from wealthier families, tend to be exposed to Cadmium, Arsenic, and inorganic Copper (Copper Sulfate).

The Great Artesian Basin: A Contested Resource Environment of Subterranean Water and Coal Seam Gas in Australia

ABSTRACTThe Great Artesian Basin (GAB) in Australia is one of the largest subterranean aquifer systems in the world. In this article we venture into the subterranean “resource environment”’ of the Great Artesian Basin and ask whether new insights can be provided by social analyses of the “vertical third dimension” in contemporary contests over water and coal seam gas. Our analysis makes use of a large number of publicly available submissions made to recent state and federal government inquiries, augmented with data obtained through ethnographic fieldwork among landholders in the coal seam gas fields of southern Queensland. We examine the contemporary contest in terms of ontological politics, and regard the underground as a challenging “socionature hybrid” in which the material characteristics, uses, and affordances of water and coal seam gas resources in the Great Artesian Basin are entangled with broader social histories, technologies, knowledge debates, and discursive contests.

Evolutionary refugia and ecological refuges: key concepts for conserving Australian arid zone freshwater biodiversity under climate change

Refugia have been suggested as priority sites for conservation under climate change because of their ability to facilitate survival of biota under adverse conditions. Here, we review the likely role of refugial habitats in conserving freshwater biota in arid Australian aquatic systems where the major long-term climatic influence has been aridification. We introduce a conceptual model that characterizes evolutionary refugia and ecological refuges based on our review of the attributes of aquatic habitats and freshwater taxa (fishes and aquatic invertebrates) in arid Australia. We also identify methods of recognizing likely future refugia and approaches to assessing the vulnerability of arid-adapted freshwater biota to a warming and drying climate. Evolutionary refugia in arid areas are characterized as permanent, groundwater-dependent habitats (subterranean aquifers and springs) supporting vicariant relicts and short-range endemics. Ecological refuges can vary across space and time, depending on the dispersal abilities of aquatic taxa and the geographical proximity and hydrological connectivity of aquatic habitats. The most important are the perennial waterbodies (both groundwater and surface water fed) that support obligate aquatic organisms. These species will persist where suitable habitats are available and dispersal pathways are maintained. For very mobile species (invertebrates with an aerial dispersal phase) evolutionary refugia may also act as ecological refuges. Evolutionary refugia are likely future refugia because their water source (groundwater) is decoupled from local precipitation. However, their biota is extremely vulnerable to changes in local conditions because population extinction risks cannot be abated by the dispersal of individuals from other sites. Conservation planning must incorporate a high level of protection for aquifers that support refugial sites. Ecological refuges are vulnerable to changes in regional climate because they have little thermal or hydrological buffering. Accordingly, conservation planning must focus on maintaining meta-population processes, especially through dynamic connectivity between aquatic habitats at a landscape scale.

Acute Toxicity of Copper Sulfate and Potassium Dichromate on Stygobiont Proasellus: General Aspects of Groundwater Ecotoxicology and Future Perspectives

Karst systems harbor large groundwater resources for human consumption and represent an important habitat for rare and unprotected specialized animals, the so-called stygofauna. Due to the highly adapted features towards underground life, together with the geographic isolation provided by the subterranean aquifers, groundwater-dwelling animals may lose the ability to face sudden changes on their ecosystems, and therefore the risk of extinction is remarkably high. A little is known about their sensitiveness, especially linked to contamination pressure in urbanized karst areas. Understanding the impact of contaminants on stygofauna is important for setting groundwater environmental quality and management of karst systems. We have investigated acute toxicity responses in two endemic stygobiont species of the peri-Mediterranean genus Proasellus from two different karst areas and in freshwater standard species Daphnia magna exposed to two contaminants (copper sulfate; potassium dichromate). Groundwater from both sites was characterized in order to depict possible responses resulting from the long-term exposition of organisms to contaminants. Stygobiont Proasellus spp. were remarkably more tolerant than the epigean D. magna. The less groundwater-adapted revealed to be more tolerant to acute exposure to both toxics, suggesting that the degree of adaptation to groundwater life can influence the acute response of Proasellus spp. to pollutants, and that the tolerance to wide environmental conditions could be a key factor in groundwater colonization. This study highlights the worldwide need to use local specimens to infer the effects of pollution in their corresponding karst systems, which is important to define specific environmental quality thresholds for groundwater ecosystems that will certainly contribute for its protection.