Search Results (161)

Mineralization of groundwater for drinking purposes is a complex parameter of groundwater chemical composition. In the Shaim oil- and gas-bearing area, as in the whole West Siberian megabasin, the main target horizon for solving the issues of domestic and technical water supply is the Oligocene aquifer. It has significant groundwater reserves to cover the needs of the population and production requirements. However, it also faces a huge anthropogenic load in the form of water withdrawal and possible contamination from the surface with oil products. In Western Siberia, various deviations in the chemical composition of groundwater of the Oligocene horizon are recorded in connection with significant water withdrawal; for example, a sharp increase in chromaticity or total iron concentration, with changes in mineralization acting as a factor necessarily accompanying these deviations. Based on the data obtained in the course of monitoring for the period from 2013 to 2023, the main factors and trends of changes in the components of mineralization of the Oligocene horizon were determined. The lithological and mineralogical peculiarities of the water-bearing rocks of the horizon, the paleogeographic conditions of its formation and their relation to trends in mineralization change were studied. Water withdrawal data were processed for two cluster water withdrawal sites (50 and 5 wells, respectively). Analysis of the results showed that the increase in water withdrawal leads to an increase in infiltration from the overlying Neogene-Quaternary aquifer, which leads to the dilution of groundwater of the Oligocene horizon and a decrease in its mineralization. Here, we show that, during further monitoring, it is necessary to pay attention to the appearance of sites where significant amounts of chloride ions are fixed in the anion composition, which can potentially lead to a sharp deterioration in the quality of drinking groundwater. Full article

The management of transboundary aquifers across the Americas faces significant challenges, especially as climate change and population growth intensify groundwater stress. Groundwater use has increased to support domestic, industrial, and agricultural demands but has been extracted through unregulated withdrawals, leading to the severe degradation of aquifer health and transboundary frictions. This study focuses on how hydro-diplomacy can accelerate the adaptive governance of shared groundwater resources in three key regions: Canada–USA, USA–Mexico, and Mexico–Guatemala–Belize. We utilized a mixed methodology by integrating a transect approach, borrowed from ecology, into the field of geopolitics. To compare the hydro-diplomatic relations and groundwater governance across a continental gradient in the Americas, we conducted a literature review and employed the TWINS conflict–cooperation matrix to evaluate governance frameworks and hydro-diplomatic interactions across time. Our findings demonstrate that hydro-diplomacy plays a pivotal role in expediting agreements, fostering transboundary data sharing, and supporting participatory governance models. In particular, the presence of supranational bodies such as the International Joint Commission (IJC) between Canada and the USA has been effective in maintaining long-term collaboration through social learning and technical cooperation. Meanwhile, in regions like Mexico–Guatemala–Belize, the absence of robust institutions has hindered progress, with limited financial and knowledge-sharing networks. This study highlights the need for improved cross-border cooperation mechanisms and the establishment of common monitoring protocols to better manage aquifer resources under the pressures of climate change. The results support the development of more adaptive transboundary groundwater management strategies aligned with Sustainable Development Goal (SDG) 6.5.2 and call for broader geopolitical cooperation to address the complexities of groundwater governance. Full article

Vertical creep along 15 ground ruptures within a 15 km long and 1.5 km wide zone has been occurring along the southeastern part of Metro Manila. Though the unusually high rates of vertical slip point to excessive groundwater withdrawal as the trigger, the evidence presented herein indicates that these may not be simple irregular subsidence fissures. Tectonic control of creep along these traces is suggested by the following: the occurrence of some of these ground ruptures along pre-existing scarps that coincide with topographic and lithologic boundaries, the left-stepping en echelon pattern of surface rupturing, and the distribution of the creeping zone within the dilational gap of the dextral strike-slip West Valley Fault (WVF). Furthermore, interpretation of an exposure across one of the creeping faults indicates reactivation by creep of a pre-existing tectonic fault zone. The paleoseismic evidence also suggests that the pre-creep slips are coseismic and dominantly strike-slip. Recognizing the occurrence of coseismic slip preceding aseismic creep is a primary consideration in assessing the potential of the WVF’s creeping segment and its adjacent segments in generating earthquakes. Tighter groundwater extraction regulations may be necessary to avoid exacerbating the effects of vertical ground deformation and the occurrence of induced seismicity. Full article

Carbonate and karst aquifers are of great importance for human water supplies, for supporting aquatic habitats and providing ecosystem services. Optimizing the groundwater withdrawals is therefore essential for obtaining the maximum flow rate for human purposes while minimizing the negative effects on the environment. In particular, when the abstraction of groundwater occurs through wells, the problem of defining the sustainable yield arises. This study analyzes pumping tests conducted in carbonate and karst aquifers in southern Italy to derive indications for defining the sustainable yield of yields. The four examined cases concern the Mesozoic–Cenozoic platform and transition pelagic carbonate rocks characterized by different degree of fracturing and karstification and hosting a carbonate aquifer with variable average groundwater yields. The analysis compared drawdown–time trends and their derivatives for 35 pumping tests with theoretical curves to identify the flow dimension. Parameters useful for examining the well yields were then determined. The results show that the response to the pumping of the investigated aquifers is very variable, both among the different sites and within the same site. Well yields are very different due to aquifer heterogeneity, local hydrostratigraphy and structural setting, and position of the pumping center within the groundwater flow system. To determine the operational pumping rate for a well in this environment, this study emphasizes the importance of analyzing drawdown trends over time to correctly predict the well’s long-term response to pumping. Specifically, when pumping induces a steady-state drawdown response, the focus for defining the sustainable abstraction shifts to the basin or aquifer scale. Conversely, when a transient drawdown response to pumping results, the well’s capacity to capture groundwater becomes the primary factor for well yield and its sustainability. Full article

Ensuring the protection of the aquatic environment and addressing the water scarcity and degradation of water quality in the Mediterranean region pose significant challenges. This study specifically aims to assess the impact of urban and industrial pollution on the ZAT River water quality. The study exploits a combination of field measurements and mathematical simulations using the PEGASE model. The objective is to evaluate how water quality changes throughout the different seasons and to determine whether olive oil factories discharge industrial wastewater into the river. The study reveals that the river water quality remains relatively stable along its course, up to km 64 in winter and km 71.77 in summer, where poor water quality is recorded. This degradation can be attributed to multiple factors. One of these factors is the discharge of industrial wastewater, which accounts for 47% of the COD pollution load. This industrial wastewater is released into the river without treatment during the production period (January–February) and inactivity period (March–May). The combined impact of urban and industrial wastewater is also associated with the decrease in water flow resulting from water withdrawals due to irrigation canals and groundwater recharge, which both contribute to the observed changes in river water quality. Importantly, field measurements combined with results obtained from the calibrated model provide compelling evidence of unauthorized wastewater discharges from the olive oil factories into the river. These results emphasize the need for stricter regulation, such as developing water quality monitoring strategies based on the use of modeling methodologies. They also emphasize the importance of improving wastewater management practices, such as setting up treatment plants for different sources of pollution or developing a co-treatment plant to mitigate the adverse impact of industrial pollution on river water quality. Full article

The terrestrial subsurface harbors unique microbial communities that play important biogeochemical roles and allow for studying a yet unknown fraction of the Earth’s biodiversity. The Saint-Leonard cave in Montreal City (Canada) is of glaciotectonic origin. Its speleogenesis traces back to the withdrawal of the Laurentide Ice Sheet 13,000 years ago, during which the moving glacier dislocated the sedimentary rock layers. Our study is the first to investigate the microbial communities of the Saint-Leonard cave. By using amplicon sequencing, we analyzed the taxonomic diversity and composition of bacterial, archaeal and eukaryote communities living in the groundwater (0.1 µm- and 0.2 µm-filtered water), in the sediments and in surface soils. We identified a microbial biodiversity typical of cave ecosystems. Communities were mainly shaped by habitat type and harbored taxa associated with a wide variety of lifestyles and metabolic capacities. Although we found evidence of a geochemical connection between the above soils and the cave’s galleries, our results suggest that the community assembly dynamics are driven by habitat selection rather than dispersal. Furthermore, we found that the cave’s groundwater, in addition to being generally richer in microbial taxa than sediments, contained a considerable diversity of ultra-small bacteria and archaea. Full article

Change in land use and land cover (LULC) is crucial to freshwater ecosystems as it affects surface runoff, groundwater storage, and sediment and nutrient transport within watershed areas. Ecosystem components such as wetlands, which can contribute to the reduction of water pollution and the enhancement of groundwater recharge, are altered by LULC modifications. This study evaluates how wetlands in the Big Sunflower River Watershed (BSRW) have changed in recent years and quantified their impacts on streamflow, water quality, and groundwater storage using the Soil and Water Assessment Tool (SWAT). The model was well calibrated and validated prior to its application. Our study showed that the maximum increase in wetland areas within the sub-watersheds of interest was 26% from 2008 to 2020. The maximum changes in reduction due to the increase in wetland areas were determined by 2% for streamflow, 37% for total suspended solids, 13% for total phosphorus (TP), 4% for total nitrogen (TN), and the maximum increase in shallow groundwater storage by 90 mm from 2008 to 2020 only in the selected sub-basins. However, the central part of the watershed experienced average declines of groundwater levels up to 176 mm per year due to water withdrawal for irrigation or other uses. This study also found that restoration of 460 to 550 ha of wetlands could increase the reduction of discharge by 20%, sediment by 25%, TN by 18%, and TP by 12%. This study highlights the importance of wetland conservation for water quality improvement and management of groundwater resources. Full article

Global forest plantations are expanding, causing land-use changes and impacting the water cycle. This study assesses whether eucalyptus plantations reduce groundwater levels compared to grasslands in paired subtropical watersheds. The hydrological dynamics of surface and subsurface water were compared in three small watersheds in southern Brazil, mainly occupied by Eucalyptus saligna (Es-W, 79.9 ha), Eucalyptus benthamii (Eb-W, 82.1 ha), and degraded anthropized natural grassland (G-W, 109.4 ha). Rainfall, flow, and piezometric levels were monitored. Runoff, evapotranspiration, and water balance in the soil profile were estimated, and the subsurface environment was characterized using electrical resistivity tomography. During higher accumulated rainfall, water surplus increased for all watersheds. In the wet period (accumulated rainfall of 1098.0 mm), evapotranspiration was higher for eucalyptus (624.3 mm for Eb-W and 512.5 mm for Es-W) than for the grassland watershed (299.5 mm), resulting in the highest runoff in G-W (649.6 mm). During the dry period (accumulated rainfall of 478.5 mm), water deficit and withdrawal were mainly observed in forested watersheds, decreasing groundwater. Combining water balance and electrical resistivity tomography estimations results in a better understanding of the hydrological dynamics in paired watersheds with different land uses. This information is useful for developing best-practice management strategies for sustainable water resource use and forest production. Full article

An accurate quantification of flow components and an understanding of water source dynamics are essential for effective water resource and quality management. However, the complexity of hydrological processes and the interference of intensive human activities pose significant challenges in precisely separating water discharge into distinct components such as surface runoff, interflow, and groundwater. The Xinanjiang (XAJ) model, a conceptual watershed hydrological model, has been developed and successfully implemented for rainfall–runoff simulations and hydrograph separations across various Chinese watersheds. While the model framework is robust, it fails to account for agricultural irrigation water withdrawals and the variations in in-stream water travel times across different hydrological regimes, introducing considerable uncertainty in simulating low-flow conditions. This study introduced modifications to the XAJ model by allowing parameter adjustments across different flow regimes and incorporating irrigation withdrawals into the runoff routing process. Utilizing a decade of hydrometeorological data (2013–2022) from the Yongan River watershed in eastern China, the modified model demonstrated improved efficiency metrics in low- and medium-flow regimes compared to the original model, with a Nash–Sutcliffe coefficient improvement from −4.43~−0.49 to 0.40~0.46, R² from 0.21~0.36 to 0.53~0.63, and BIAS reduction from 7.60~89.08% to 2.06~12.71%. Furthermore, the modified XAJ model provided a more accurate estimation of the spatial and temporal distribution of streamflow components across sub-watersheds. The original model tended to overestimate groundwater contributions (13%) and underestimate interflow (14%), particularly in low-flow conditions. The enhanced XAJ model, thus, offers a more effective tool for identifying streamflow components, providing essential insights into hydrological processes for better management decisions. Full article

The Ogallala aquifer, underlying eight states from South Dakota to Texas, is practically non-recharging south of Nebraska, and groundwater withdrawals for irrigation have lowered the aquifer in western Kansas. Subsequent well-yield declines encourage deficit irrigation, greater reliance on precipitation, and producing profitable drought-tolerant crops like upland cotton (Gossypium hirsutum (L.)). Our objective was to evaluate deficit irrigated cotton growth, yield, and water productivity (CWP) in northwest, west-central, and southwest Kansas in relation to El Niño southern oscillation (ENSO) phase effects on precipitation and growing season cumulative thermal energy (CGDD). Using the GOSSYM crop growth simulator with actual 1961–2000 location weather records partitioned by the ENSO phase, we modeled crop growth, yield, and evapotranspiration (ET) for irrigation capacities of 2.5, 3.75, and 5.0 mmd⁻¹ and periods of 4, 6, and 8 weeks. Regardless of location, the ENSO phase did not influence CGDD, but precipitation and lint yield decreased significantly in southwest Kansas during La Niña compared with the Neutral and El Niño phases. Simulated lint yields, ET, CWP, and leaf area index (LAI) increased with increasing irrigation capacity despite application duration. Southwestern Kansas producers may use ENSO phase information with deficit irrigation to reduce groundwater withdrawals while preserving desirable cotton yields. Full article

Groundwater-dependent cultivation is imperative to meet the ever-increasing food demands in Egypt. To explore the Moghra aquifer’s potential, where a large-scale rural community is being established, a finite element groundwater flow (i.e., FEFLOW^®) model was invoked. The developed model was calibrated against the observed water levels. GRACE-based groundwater storage was incorporated into the tuning procedure of the developed model. Eight abstraction rates from 1000 wells, changing from 800 to 1500 m³/day/well, were simulated for a 100-year test period. The maximum resulting drawdown values, respectively, ranged from 59 to 112 m equating to about 20–40% of the aquifer’s saturated thickness. The implications of the climate change from gradual sea level rise and an increase in crop consumptive water use were investigated. Extending seawater invasion into the aquifer caused a slight increase in the piezometric levels within a narrow strip along the seaside. Applying a chronologically increasing withdrawal rate to meet the projected increment in crop water requirements raised the maximum resulting drawdown by about 7.5%. The sustainable exploitation regime was defined as a time-increasing withdrawal rate adequate to reclaim 85,715 acres (34,688 ha). The recommended development scheme is compatible with the withdrawal rationing rule, aiming to maintain that the resulting drawdown does not exceed one meter a year. Full article

Water resources are scarce and difficult to manage in Kazakhstan, Central Asia (CA). Anthropic activities largely eliminated the Aral Sea. Afghanistan’s large-scale canal construction may eliminate life in the main stream of the Amu Darya River, CA. Kazakhstan’s HYRASIA ONE project, with a EUR 50 billion investment to produce green hydrogen, is targeted to withdraw water from the Caspian Sea. Kazakhstan, CA, requires sustainable programs that integrate both decision-makers’ and people’s behavior. For this paper, the authors investigated groundwater resources for sustainable use, including for consumption, and the potential for natural “white” hydrogen production from underground geological “factories”. Kazakhstan is rich in natural resources, such as iron-rich rocks, minerals, and uranium, which are necessary for serpentinization reactions and radiolysis decay in natural hydrogen production from underground water. Investigations of underground geological “factories” require substantial efforts in field data collection. A chemical analysis of 40 groundwater samples from the 97 wells surveyed and investigated in the T. Ryskulov, Zhambyl, Baizak and Zhualy districts of the Zhambyl region in South Kazakhstan in 2021–2022 was carried out. These samples were compared with previously collected water samples from the years 2020–2021. The compositions of groundwater samples were analyzed, revealing various concentrations of different minerals, natural geological rocks, and anthropogenic materials. South Kazakhstan is rich in natural mineral resources. As a result, mining companies extract resources in the Taraz–Zhanatas–Karatau and the Shu–Novotroitsk industrial areas. The most significant levels of minerals found in water samples were found in the territory of the Talas–Assinsky interfluve, where the main industrial mining enterprises are concentrated and the largest groundwater deposits have been explored. Groundwater compositions have direct connections to geological rocks. The geological rocks are confined to sandstones, siltstones, porphyrites, conglomerates, limestones, and metamorphic rocks. In observation wells, a number of components can be found in high concentrations (mg/L): sulfates—602.0 (MPC 500 mg/L); sodium—436.5 (MPC 200 mg/L); chlorine—465.4 (MPC 350 mg/L); lithium—0.18 (MPC 0.03 mg/L); boron—0.74 (MPC 0.5 mg/L); cadmium—0.002 (MPC 0.001 mg/L); strontium—15, 0 (MPC 7.0 mg/L); and TDS—1970 (MPC 1000). The high mineral contents in the water are natural and comprise minerals from geological sources, including iron-rich rocks, to uranium. Proper groundwater classifications for research investigations are required to separate potable groundwater resources, wells, and areas where underground geological “factories” producing natural “white” hydrogen could potentially be located. Our preliminary investigation results are presented with the aim of creating a large-scale targeted program to improve water sustainability in Kazakhstan, CA. Full article

Groundwater resources are crucial to socio-economic development and the ecosystem, and over-extraction can cause the groundwater level to drop, deplete reserves, and trigger geological hazards like land subsidence. The North China Plain (NCP) has experienced both subsidence and groundwater depletion due to over-extraction in the past 70 years. In this study, we used MT-InSAR technology and ascending C-band Sentinel-1 SAR data from 2017 to 2023 to study land deformation in the junction area of Shijiazhuang–Baoding–Cangzhou–Hengshui. We identified multiple subsidence funnels with a maximum rate exceeding −150 mm/year and a total deformation surpassing 600 mm. Seasonal decomposition methods accurately separated seasonal signals in the time-series deformation and groundwater level data. An exponential function model applied to long-term deformation showed no significant decrease in subsidence in severely affected areas. By modeling seasonal deformation and seasonal groundwater levels, we determined the elastic skeletal storage coefficients (S_ke) to be in the range of 1.02 × 10⁻³~6.53 × 10⁻³ in subsidence areas. We obtained the spatiotemporal evolution of the total groundwater storage (TGWS), irreversible ground storage (IGWS), and recoverable ground storage (RGWS). The TGWS and IGWS decreased annually while the RGWS increased, which is attributable to the implementation of the South-to-North Water Diversion Project (SNWDP) and the issuance of groundwater withdrawal policies in the NCP. Full article

This study addresses the imperative to comprehend gravity shifts resulting from groundwater storage (GWS) variations in the Arabian Peninsula. Despite the critical importance of water resource sustainability and its relationship with gravity, limited research emphasizes the need for expanded exploration. The investigation explores the impact of GWS extraction on the gravity field, utilizing Gravity Recovery and Climate Experiment (GRACE) and Global Land Data Assimilation System (GLDAS) data in addition to validation using the WaterGAP Global Hydrology Model (WGHM). Spanning April 2002 to June 2023, this study predicts GWS trends over the next decade using the Seasonal Autoregressive Integrated Moving Average (SARIMA) model. The comprehensive time-series analysis reveals a significant GRACE-derived groundwater storage (GWS) trend of approximately −4.90 ± 0.32 mm/year during the study period. This trend has a notable impact on the gravity anomaly (GA) values, as observed through the decomposition analysis. The projected GWS indicates a depletion rate of 14.51 km³/year over the next decade. The correlation between GWS and GA is substantial at 0.80, while the GA and rainfall correlation is negligible due to low precipitation rates. Employing multiple linear regression explains 80.61% of the variance in gravity anomaly due to GWS, precipitation, and evapotranspiration. This study investigates climate change factors—precipitation, temperature, and evapotranspiration—providing a holistic understanding of the forces shaping GWS variations. Precipitation and evapotranspiration exhibit nearly equal values, limiting GWS replenishment opportunities. This research holds significance in studying extensive GWS withdrawal in the Arabian Peninsula, particularly concerning crust mass stability. Full article

The aquifers of the Togolese coastal sedimentary basin are the principal sources of water for almost half of the country’s population. These aquifers’ features have not been adequately monitored and studied. The resource is threatened by human activities, notably agriculture, industry, and withdrawals for drinking water supplies. This situation is exacerbated by the potential effects of climate change. For this research, a basin-scale study was conducted to estimate current groundwater recharge and its future evolution in response to climate change. A recharge model based on Thornthwaite–Mather balance equations using runoff coefficients characterizing land use was fed with current and future climate data from an optimistic scenario (RCP 4.5) and a pessimistic scenario (RCP 8.4). Despite the associated uncertainties, the soil–water balance model at monthly time steps predicts a recharge of 3 to 455 mm per year from 2020 to 2039, and 40 to 420 mm per year from 2040 to 2059 under the optimistic RCP 4.5 scenario. According to the pessimistic RCP 8.5 scenario, the recharge will range between 16 and 515 mm per year from 2020 to 2049 and from 1 to 467 mm per year between 2040 and 2059. As a result, the basin’s groundwater recharge range, which is currently 47 to 225 mm, will significantly increase. This study provides a scientific basis for the sustainable management of groundwater in the Togolese coastal sedimentary basin. The recharge of the groundwater in the basin will increase regardless of the climate scenario and will support future development in the Togolese coastal sedimentary basin. Full article