Groundwater for Sustainable Development最新文献

Coastal aquifers worldwide can be considered an essential water source required for preservation of the coastal ecosystems. However, these aquifers are vulnerable to seawater intrusions and over-pumping due to their proximity to the sea and human activities, respectively. Therefore, the investigation of recharge mechanism has special importance in the regions of tectonic rift activities where they exhibit complex geological structures and hydrogeological characteristics. In the current research, an integrated approach of remote sensing and environmental isotopes together with field investigation and subsurface datasets (aeromagnetic, gravity and well logs) are employed to identify the nature and factors affecting groundwater recharge of the Miocene coastal aquifer along the Red Sea-Gulf of Suez western margin (continental rift basin). The research findings reveal that: (1) The coastal Miocene aquifer consists of both clastic (sandstone, sand and gravels) and carbonate rocks (limestone and dolomite) with subsurface thickness ranges between 100 and 200 m. (2) Its groundwater shows contrast salinity values (expressed by total dissolved solids, TDS) between 2755 and 10,996 mg/l, due to the variation in recharge rates and the lithologic dissimilarity of the water bearing formations. (3) The environmental isotopes indicate that the Miocene groundwater has a mixed isotopic signature between modern meteoric (rainfall) and fossil waters. (4) The isotopic data of the Miocene aquifer and the enriched Gulf of Suez verifies that no seawater intrusions are affecting this aquifer with existing hydraulic barriers (clogged/sealed faults or impermeable massive blocks). (5) The hydrogeomorphological investigations, aeromagnetic and gravity data reveal an existence of two morphotectonic depressions (water collectors) which have paleo and recent recharge opportunities for the subsurface sedimentary layers (2–4 km thick). From the applied viewpoint, these two depressions have potential prospects for future groundwater exploration, which has significant impact on food security and land reclamation.

Delineation of groundwater potential zone in coastal region is a challenging task. One of the reasons for that is lack of understanding of the geogenic factors in the coastal alluvial areas such as geomorphology, lithology etc. These factors can influence the locations of the groundwater potential zones over the coastal alluvial terrains. The present study is an attempt to analyse the multiple factors to delineate groundwater potential zones in the coastal region of Contai Sub-division, West Bengal, India. In this study, remote sensing, geographic information system (GIS) and multi-criteria decision analysis (MCDA) techniques have been utilized to delineate the groundwater potential zones. Weights were assigned to the parameters using the analytical hierarchical process (AHP) and different classes within each parameter have been ranked on the basis of their relative importance regarding groundwater potentiality. The results of the study were validated by water yield data, water level fluctuation data and geophysical survey. The outcome of validation reveals that a strong correlation (80%) exists between water yield data and groundwater potential zones. Similarly, a good relation occurs for the water level fluctuation data and groundwater potential zones, where the overall accuracy and kappa coefficients are 84.2% and 0.76 respectively. The output of the study reveals that geomorphologically older deltaic plain, older alluvial plain and older coastal plain are good indicators of high groundwater potential regions. Furthermore, the outcome of the study also unveils that lithologically the well sorted medium grained sand is important feature to delineate high groundwater potential regions in coastal alluvial areas. The findings, thus, could establish that present methodology using GIS and AHP techniques has a better potential to identify and map the groundwater potential zones more realistically and can be applied for future planning of groundwater resource management and groundwater exploration in wider coastal alluvial terrain.

Groundwater in the Beijing-Tianjin-Hebei (BTH) region has been overdrawn for a long time, and groundwater pollution is severe. Groundwater well fields (GWFs) face resource- and environment-related pressures, and their safety is a key issue restricting regional social and economic development. We evaluated the groundwater quality and drinking suitability via the entropy-weighted water quality index and the overall health risks to adults and children with an improved model. Furthermore, the risks to GWF resources were determined based on the groundwater level and its variation. The higher Na⁺ and NO₃⁻ concentrations were mainly due to agricultural and industrial activities. Forty-seven GWFs approached the Class Ⅳ water standard, and 25 and 4 GWFs posed high health risks to adults and children, respectively, suggesting environmental risks. Moreover, the average annual groundwater level in the groundwater depression cone of 2 shallow and 6 deep GWFs decreased by 0.25 and 3.2 m, respectively. These GWFs were substantially threatened by groundwater resource attenuation. The groundwater level of 4 GWFs slowly declined, but a deep groundwater depression cone was not formed. However, the risk to groundwater resources remained high. The resource-related and environmental risks of GWFs in the BTH region were synchronous, but the resource-related risk was higher.

Groundwater is the most vital and reliable source of fresh water globally. This study examined the variability in Depth to Water table (DTW) below ground level in agriculture-dominated Bari interfluve, Pakistan. Observing water levels empowers access and management of water resources ensuring long-term availability. Changes in the DTW were observed by preparing spatiotemporal maps using piezometric data for both pre-monsoon and post-monsoon seasons by five-year difference intervals from 2005 to 2020. Piezometric observations offer more precise real-time monitoring of subsurface water levels. The trend of the groundwater table was analyzed by non-parametric methods i.e., Mann-Kendall (MK) and Sen's slope estimator in all observation wells of districts at a significance level of 5 percent for sustainable groundwater resource management. The resulting trend of fluctuating water table showed a progressive decline in water level in all districts except a minor increase was also noticed. The seasonal fluctuation (between pre-monsoon and post-monsoon seasons) showed that the average DTW was found to be high in 46% of the total tehsils in the post-monsoon season while in 42% it was low and 12% depicted no change compared to pre-monsoon season. Piezometric observation points of DTW exhibiting a trend at a 5 percent significance level were used to project future water table depths that indicated a further alarming depleting trend for both the pre-monsoon and post-monsoon seasons in lower districts of Bari interfluve. The groundwater pattern calls for precautionary measures to see a reversal in trend or even maintain the groundwater levels for future needs.

Maintaining water quality is essential to protect human health from elevated levels of radon, a water-soluble radioactive gas that can pose serious risks when levels are above safe thresholds. This study evaluated the radon levels in groundwater sources in the Baramulla district of Jammu and Kashmir using a scintillation-based smart RnDuo detector. The levels of radon showed significant fluctuations, ranging from 19 ± 0.7 to 93 ± 1.5 Bq L⁻¹, with an arithmetic mean of 41.3 ± 1.0 Bq L⁻¹. Notably, 51 % of the samples exceeded the limits set by USEPA (11 Bq L⁻¹) and UNSCEAR (40 Bq L⁻¹), yet all of them remained below the WHO's guideline of 100 Bq L⁻¹. Furthermore, 13 % of the samples exceed 60 Bq L⁻¹. Annual inhalation and ingestion doses vary across age groups surpassing the WHO recommendations for drinking water quality but lying below the UNSCEAR 1000 μSv y⁻¹ suggested levels. Importantly, the mean annual effective dose throughout all age groups falls well below the ICRP range (3–10 mSv y⁻¹). The analysis suggested that radon exposure could lead to 0.52 to 3 excess cancer cases per thousand people, with average values for all age groups remaining less than the permitted value of 1.45 × 10⁻³ as suggested by UNSCEAR. The study also explores physiochemical parameters, aiding future epidemiological studies and fault investigations.

Groundwater surface (GWS), which denotes the vertical extent of the water table or the volume of subterranean water within geologic formations, is pivotal for effective groundwater resource management. Accurately predicting GWS requires comprehensive and precise data to fully understand the influencing factors. The inherent temporal complexity and often incomplete datasets of GWS pose significant challenges to accurate assessments. This research aims to devise a comprehensive method that merges interpolation and prediction techniques to develop a functional model and dynamic system for GWS prediction. The study was conducted on the Azarshahr Plain aquifer in Iran, involving 34 observation wells with partially or entirely missing data. Initial analysis utilized three interpolation methods—Kriging, Support Vector Machine (SVM), and M5P—with the M5P method emerging as the most accurate, evidenced by the lowest Root Mean Square Error (RMSE) of 1.83. Two subsequent scenarios were examined: (1) using the M5P method to interpolate missing data for all 34 wells, and (2) using only data from 15 wells with complete records. GWS levels were predicted using Deep Neural Network (DNN) and Convolutional Neural Network (CNN) models. Comparative analysis highlighted the superior performance of the CNN model in both scenarios, particularly noting its effectiveness in GWS prediction. The improvement of data quality through interpolation significantly enhanced predictive accuracy by approximately 90 percent, thereby increasing the reliability of the predictive models for future groundwater management decisions.

Arsenic (As) contamination in groundwater is a well-established concern. Several studies have explored the possibility of immobilizing arsenite [As (III)] in-situ within the aquifer. Recent studies show a uniform distribution of ferrous sulfate (FeS) synthesized within homogenous porous media and demonstrated promising performance in immobilizing As(III). Upscaling from bench-scale to field-scale systems involves the integration of physical and chemical heterogeneities. Thus, the distribution of reducing agent (i.e., FeS), subsequent capturing of As(III) in the upscaled heterogeneous porous media system is a complex and uncertain phenomenon. Therefore, this study focuses on assessing the performance of FeS when synthesized for multiple cycles under constant flow and constant head conditions for immobilization of As(III) through a heterogeneous porous media system. A 3-D heterogenous porous media system is first simulated using a sequential indicator simulator model (SISIM). Then, the same heterogeneous media is prepared in the laboratory by packing three different-sized sand within a 3-D tank (0.67 m × 0.40 m × 0.40 m) which is subdivided into a total of 150 grids (0.096 m × 0.08 m × 0.08 m). FeS is synthesized in-situ by sequential injection of sodium sulfide (Na₂S) and ferrous sulfate (FeSO₄‧6H₂O), as detailed in the previous study. The outcome of the study suggests that flow within the model subsurface porous media is non-uniform and follows an inter-connected preferential flow path. The progression of in-situ synthesized FeS is faster in the areas of higher hydraulic conductivity. The immobilization of As (88%) is promising by FeS synthesized within heterogeneous porous media. An overall reduction of porosity (7.7%) and hydraulic conductivity (68.3%) are observed, which is more predominant along the preferential flow path where deposition of FeS is significantly higher. To maintain constant flow rate, 60% increase in head difference is required. Whereas the flow rate decreases by 47.2% when constant head condition is adopted. Overall, the newly synthesized FeS shows promising performance in immobilizing As(III) within heterogeneous model subsurface porous media; however, there might be some possibility of pore-clogging and bypassing of flow due to deposition and subsequent retention of As, which may impact the As removal efficiency in the longer run.

Groundwater is a significant source of freshwater supply globally. State-mandated groundwater regulatory frameworks are often pervasive and have failed to reap tangible outcomes. The participatory approach of groundwater governance has surfaced to understand human-groundwater relations through collective action going beyond the techno-managerial paradigm. Hence, the study is carried out to provide a comprehensive and systematic review of the evolution and trends of research in groundwater governance and collective action deploying bibliometric analysis to understand the political economy of groundwater. A total of 356 scholarly peer-reviewed and grey literature published from 2000 to 2022 was compiled. A substantial increase in publications after 2013 was observed. USA and India lead in publication contributions in terms of geographical distribution. Three peer-reviewed journals were prominent publishing outlets: Hydrogeology, Water, and Water Alternatives. The analysis of 814 keywords co-occurrence shows that "groundwater," "governance," and "collective action" were the most extensively used keywords. The emerging themes observed are governance and institutions, cooperative management, and policy. Our findings signify that cooperative management or collective action will be prioritised to understand human-groundwater relations by making the invisible resource visible integrating socio-cultural perspectives.

The Peroxone process—which utilizes a combination of ozone and hydrogen peroxide to generate hydroxyl radicals—is frequently used in groundwater remediation to effectively remove ozone-resistant contaminants. However, some monocyclic aromatic compounds with low ozone reactivity have been found to be removed by ozone solely (without the need for hydrogen peroxide) through a self-enhanced mechanism. This self-enhanced removal occurs when the interaction of ozone with hydroxide ion generates sufficient amount of hydroxyl radicals, initiating a radical reaction that subsequently propagates through the degradation intermediates. This study leverages the self-enhanced degradation mechanism for the treatment of ozone-resistant compounds during groundwater remediation. Key environmental conditions, including water alkalinity and contaminant concentration, were investigated for their effect on the self-enhanced degradation of para-chloro benzoic acid (pCBA), which served as a model for ozone-resistant compounds. High pCBA removal was observed during ozonation in the concentration range of 0.5–5 μM, where the decay kinetics of pCBA and ozone significantly dependent on the initial pCBA concentration. Furthermore, decreased pCBA removal was noted in water matrices with increased alkalinity, largely due to the scavenging of OH radicals by carbonate species. Finally, pCBA removal was investigated in natural groundwater, where co-existing substances acted as ozone/radical scavengers, leading to reduced pCBA removal. Overall, this study highlights the importance of the self-enhanced removal mechanism of monocyclic aromatic contaminants when treating water with high contamination levels and low-to-moderate alkalinities.

Tehsil Mardan has experienced enormous shifts in land use and cover (LULC), growth in population, climate variance, and a drop in the groundwater table. This study sought to evaluate and quantify the vulnerability status of municipal water security in Tehsil Mardan, by incorporating LULC, population, and climate indicators using remote sensing and statistical techniques. LULC changes were quantified from Landsat imageries using Envi from 1990 to 2021. Field and questionnaire surveys were conducted to estimate groundwater depletion and municipal water demand. The Mann-Kendall trend test was applied to temperature and precipitation data. Analysis of correlation was performed to measure the relationship among all the variables. To get a deeper understanding of the vulnerability of municipal water security caused by physical, climatic, and social factors, the analytical hierarchy process (AHP) was utilized. LULC results showed a fivefold rise in built-up class from 37 km² to 188 km² and a substantial decline in bare land from 437 km² to 252 km² from 1990 to 2021. The average groundwater table depletion was one foot per year and showed a significant positive correlation with the number of tube wells, water supply and demand, and population growth. An increase of 0.008 °C per year in average temperature while a declining trend is observed in mean precipitation during the last 30 years. The results showed that municipal water security vulnerability changed from “invulnerable relatively” to “very vulnerable” stage during the last three decades. The study contributed valuable insights to facilitate policymakers, and urban planners for management of the current and future municipal water works, land use planning, and associated environmental opportunities and threats.