Groundwater for Sustainable Development最新文献

{"title":"Enhancing infiltration water quality through reactive organic layers: field-scale evaluation of soil-aquifer treatment managed aquifer recharge using treated wastewater","authors":"Selcuk Oral,&nbsp;Teresa E. Leitão,&nbsp;Tiago N. Martins,&nbsp;Nuno Correia,&nbsp;Patrícia Palma,&nbsp;Sukran Acikel,&nbsp;Mehmet Ekmekci","doi":"10.1016/j.gsd.2026.101676","DOIUrl":"10.1016/j.gsd.2026.101676","url":null,"abstract":"<div><div>Declining water availability and increasing water demand highlight the need to improve water supply security and adopt sustainable water management approaches involving alternative water resources. Managed aquifer recharge (MAR) uses alternative water resources, enhancing groundwater storage while ensuring its quality. This study presents results from a field-scale soil-aquifer treatment managed aquifer recharge (SAT-MAR) system, representing the first application in Portugal using basins to infiltrate treated wastewater from the Comporta Wastewater Treatment Plant (WWTP). By comparing the performance of different infiltration basins, the study verified infiltration water quality improvement during vadose zone passage and evaluated groundwater deterioration risks. The system performance was examined across three infiltration basins (B). B1 and B2 were ameliorated with reactive organic layers (ROLs), containing a mixture of sand, 30% biochar and 15% granular activated carbon (GAC), respectively, compared to B4 with plain sand. The ROLs, designed as nature-based and energy-free, allowed a sustainable tertiary treatment for alternative water resources. GAC-ROL achieved superior pharmaceutical compounds (PhCs) removal (77%), compared to B1 (15%) and B4 (12%), reducing hydrophobic and polar compounds below quantification limits, including hydrochlorothiazide and sulfamethoxazole. Compound-specific adsorption and biodegradation patterns, characterized by pK_a and logK_ow, confirmed the higher retention capacity of GAC-ROL. The receiving aquifer showed ∼33% reduction of organic matter indicators (TOC, COD, UV254). Median stable pH (∼6.2) and redox (∼87 mV), indicated system buffering capabilities. Nutrients surpassed the groundwater (APA, 2023) regulatory thresholds in both vadose zone and groundwater, emphasizing the need for enhanced optimization at the WWTP. This study provides strong evidence that integrating ROLs into SAT-MAR systems enhances performance and improves TWW quality.</div></div>","PeriodicalId":37879,"journal":{"name":"Groundwater for Sustainable Development","volume":"34 ","pages":"Article 101676"},"PeriodicalIF":5.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148729664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From curve fitting to scientific machine learning: A critical synthesis of solute transport modeling and breakthrough curve interpretation","authors":"Linsong Liu,&nbsp;Debao Lu,&nbsp;Jian Ou,&nbsp;Yuping Han,&nbsp;Cundong Xu,&nbsp;Junzheng Zhu,&nbsp;Jianhua Si","doi":"10.1016/j.gsd.2026.101679","DOIUrl":"10.1016/j.gsd.2026.101679","url":null,"abstract":"<div><div>Solute breakthrough curves serve as fundamental diagnostic metrics for characterizing mass transport mechanisms in hydrogeological systems. Traditional interpretations relying exclusively on boundary outlet sampling and deterministic inversion inherently suffer from severe mathematical ill-posedness and equifinality. Resolving these structural limitations necessitates a methodological transition toward high-dimensional internal sensing and probabilistic parameterization. This review presents a critical synthesis of how advanced observational constraints and scientific machine learning are fundamentally reshaping solute transport modeling. We evaluate the progression from classical iterative algorithms to ensemble-based data assimilation frameworks capable of reconstructing complex spatial heterogeneity. Furthermore, we critically assess the operational trade-offs of modern artificial intelligence paradigms. This evaluation analyzes the capacity of probabilistic generative surrogates to ensure robust uncertainty quantification and examines the role of physics-informed neural networks in enforcing mass conservation, while explicitly addressing their optimization instabilities when deployed on noisy field datasets. To organize model and algorithm selection, we develop a structured Complexity–Model–Data framework that relates diagnostic evidence for process complexity to candidate transport formulations and the observational support available for inversion. Dimensionless indicators and BTC morphology are used to narrow the set of plausible models, whereas data density, computational demand, and uncertainty requirements inform the selection of deterministic, probabilistic, data-assimilation, or physics-informed methods. A one-dimensional synthetic case illustrates how this reasoning can be implemented under controlled conditions. The framework provides a practical basis for transparent, site-specific model evaluation while preserving the roles of hydrogeological interpretation, measurement quality, management objectives, and expert judgment.</div></div>","PeriodicalId":37879,"journal":{"name":"Groundwater for Sustainable Development","volume":"34 ","pages":"Article 101679"},"PeriodicalIF":5.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148730335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Graph-constrained diagnosis of groundwater evolution, fluoride mobilisation and nitrate loading in climate-stressed dryland aquifers of Northern Ghana","authors":"Ebenezer Aquisman Asare,&nbsp;Dickson Abdul-Wahab","doi":"10.1016/j.gsd.2026.101675","DOIUrl":"10.1016/j.gsd.2026.101675","url":null,"abstract":"<div><div>Groundwater sustains rural livelihoods across semi-arid West Africa, but the connected pathways by which dryland aquifers become chemically evolved remain difficult to diagnose from sparse monitoring data. Here we present a graph-constrained hydrogeochemical framework that represents boreholes as connected nodes embedded in geology, climate stress, land use and chemical state space. Applied to 160 boreholes and 320 wet and dry season samples from northern Ghana, the framework organises Voltaian sedimentary, Birimian fractured basement, granitoid and regolith/alluvial aquifers into recharge weathering, fluoride mobilisation, nitrate loading and salinity evolution corridors. The framework was evaluated using leave-one-region-out cross-validation against hydrochemistry-only and non-spatial hydroclimate baselines. Fluoride enrichment is most consistent with alkaline geogenic weathering pathways, whereas nitrate enrichment is consistent with shallow agro-domestic and agricultural connectivity. Regional aridification indicators and dry season chemistry together show a shift from recharge-like waters towards more mineralised, fluoride enriched and nitrate affected states. The graph-based workflow yielded modestly higher transfer performance and clearer process attribution than both baselines. The approach reframes groundwater quality assessment as network-based diagnosis of aquifer evolution in data-limited drylands. Unlike conventional site-by-site classification, the workflow tests whether inferred transitions are simultaneously consistent with sparse network connectivity, aquifer type, reaction plausibility and cross-region transfer.</div></div>","PeriodicalId":37879,"journal":{"name":"Groundwater for Sustainable Development","volume":"34 ","pages":"Article 101675"},"PeriodicalIF":5.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148729877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence of occurrence and oxidation of pyrite, arsenopyrite and cobaltite as the potential source of groundwater arsenic contamination in Chhattisgarh, Central India","authors":"Swati Ganveer,&nbsp;Kamal Lochan Pruseth","doi":"10.1016/j.gsd.2026.101668","DOIUrl":"10.1016/j.gsd.2026.101668","url":null,"abstract":"<div><div>Arsenic contamination in southwestern Chhattisgarh, Central India, has been identified as a serious environmental concern, with approximately 90% of sampled sites exceeding the World Health Organization’s permissible limit. The contamination is widespread yet spatially variable, reflecting the influence of underlying geological controls. This study addresses a critical knowledge gap by evaluating the possible pathways of arsenic release into groundwater. Petrographic and mineralogical observations indicate that the oxidation of pyrite (<span><math><msub><mrow><mi>FeS</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>) and arsenopyrite (<span><math><mi>FeAsS</mi></math></span>) hosted within pegmatitic veins in granite represents sources of arsenic. In addition, cobaltite (<span><math><mi>CoAsS</mi></math></span>) and arsenian pyrite identified in basalt, metabasalt, and rhyolite may also influence groundwater chemistry locally. Structural features, particularly local and regional fracture networks, show spatial association with contamination sites and may indirectly facilitate groundwater circulation. These findings suggest the complex interplay of lithology, mineralogy, fluid characteristics and structural control in governing the geogenic arsenic contamination of groundwater in this area. This paper not only provides potential mineralogical evidence but also reveals the multi-rock geogenic arsenic fertility along with hydrochemical factors that must be integrated into future predictive models.</div></div>","PeriodicalId":37879,"journal":{"name":"Groundwater for Sustainable Development","volume":"34 ","pages":"Article 101668"},"PeriodicalIF":5.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148640373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Iron-induced nanoscale restructuring of birnessite drives functional shifts in groundwater biofilters for iron and manganese removal","authors":"Jérôme Ducret,&nbsp;Benoit Barbeau","doi":"10.1016/j.gsd.2026.101666","DOIUrl":"10.1016/j.gsd.2026.101666","url":null,"abstract":"<div><div>Iron and manganese frequently co-occur in groundwater and are commonly removed by biological filtration. While long-term Mn removal is predominantly driven by abiotic oxidation on birnessite-coated media, the impact of iron on this catalytic system remains poorly understood. This study investigated the structural, mineralogical, and microbiological organization of a full-scale groundwater biofilter treating Fe– and Mn-bearing water seven years after start-up. Scanning electron microscopy revealed a Fe-rich surface overlayer at the top of the filter, overlying a MnOx coating present throughout the bed. Fe K-edge EXAFS analysis demonstrated that this poorly crystalline Fe phase is ferrihydrite-like and exhibits short Fe–Mn distances (∼2.88 Å), consistent with close structural association with underlying birnessite rather than isolated ferrihydrite precipitation. Despite substantial Fe loading, MnOx remained predominantly abiotic turbostratic birnessite (AOS 3.61–3.67). Biofilm analyses showed increased metabolic activity and dominance of filamentous bacteria affiliated with the genus <em>Crenothrix</em> compared to a Mn-only filter media. Biokinetic assays performed on the extracted biofilm revealed similar Mn(II) oxidation rates (<em>k</em> = 1.2 h⁻¹) but a 25-fold reduction in biological Mn oxidation capacity relative to a Mn-only biofilter, indicating a functional shift toward Fe removal rather than Mn accumulation. These findings demonstrate that iron does not merely compete with manganese but restructures the mineral and microbial architecture of the biofilter, altering its long-term functional trajectory. Spatial separation of Fe and Mn removal may help preserve Mn polishing capacity and biofilter stability in groundwater treatment systems.</div></div>","PeriodicalId":37879,"journal":{"name":"Groundwater for Sustainable Development","volume":"34 ","pages":"Article 101666"},"PeriodicalIF":5.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148640375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Irrigation as a dissemination vector for groundwater antibiotic resistomes into agricultural systems","authors":"Lide Gu,&nbsp;Wei Zhang,&nbsp;Jufeng Li,&nbsp;Danshi Zhao,&nbsp;Jingze Liu","doi":"10.1016/j.gsd.2026.101667","DOIUrl":"10.1016/j.gsd.2026.101667","url":null,"abstract":"<div><div>Groundwater irrigation acts as a pivotal vector for the dissemination of antibiotic resistance genes (ARGs) throughout agricultural ecosystems, yet its role in shaping crop resistomes remains poorly quantified. This study employed multi-compartment sampling (groundwater, soil, maize tissues) coupled with 16S rRNA amplicon sequencing and shotgun metagenomics to track ARG dynamics in a real-world groundwater-irrigated maize system. The results revealed that groundwater constitutes a substantial reservoir of diverse ARGs and mobile genetic elements (MGEs), exhibiting 13-15 times higher MGE abundance than soils. Crucially, irrigation facilitated the transfer of clinically relevant ARGs (e.g., <em>OXA-181</em>, <em>dfrA21</em>) and MGEs (transposases, <em>IS91</em>) into soils, triggering pronounced ARG enrichment in rhizosphere and endophytic microhabitats. Metagenomic assembly revealed groundwater-derived Pseudomonadota as key ARG hosts, while soil-specific Acidobacteriota harbored unique resistances (e.g., <em>FOX-4</em>, <em>vanD</em>). Network analyses confirmed intensified ARG-MGE co-occurrence from groundwater to rhizosphere soils (from 35.5% to 54.9% positive correlations), indicating enhanced horizontal gene transfer potential. Critically, maize kernels showed selective enrichment of Enterobacteriaceae carrying multidrug resistance, directly linking groundwater-sourced ARGs to edible crop compartments. These findings reveal groundwater irrigation as an underappreciated driver of crop ARG diversity, posing tangible food safety risks through potential human exposure to resistant bacteria and promoting ecological resistance dissemination via MGE-mediated soil recombination hotspots.</div></div>","PeriodicalId":37879,"journal":{"name":"Groundwater for Sustainable Development","volume":"34 ","pages":"Article 101667"},"PeriodicalIF":5.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148640378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sustainable nitrate mitigation from groundwater through fixed bed adsorption system: An affordable and scalable prospective approach","authors":"Roohmoney Roohmoney,&nbsp;Sumedha Chakma,&nbsp;Ravinder Kaur","doi":"10.1016/j.gsd.2026.101670","DOIUrl":"10.1016/j.gsd.2026.101670","url":null,"abstract":"<div><div>Nitrate contamination of groundwater is a growing global concern, particularly in rural and resource-limited regions where energy-intensive treatment technologies are impractical. Hence, present study attempts to compare the nitrate removal efficiency of five low-cost granular adsorbents (such as Granular Activated Carbon (GAC), Activated Alumina Balls, Purozite, Autoclaved Aerated Concrete, and Limestone) under zero-energy, gravity-driven, neutral pH conditions using fixed-bed adsorption columns. Among the test adsorbents, GAC was observed to be exhibiting the highest (i.e., 69 to 87%) nitrate removal efficiency. Kinetic and isotherm analysis of the shortlisted adsorbent (i.e., GAC), along with its detailed physicochemical characterization (in terms of BET, FTIR, pH_PZC, and SEM-EDS), indicated multilayered pseudo-second-order kinetics as the suggested mechanism for the adsorption of the nitrate ions on the positively charged (pH_PZC = 8.12) heterogeneous surface of the meso-microporous adsorbent under neutral pH conditions (i.e., at pH &lt; pH_PZC = 8.12). The shortlisted adsorbent could maintain reasonable performance over 17 maintenance-free adsorption cycles and could be effectively regenerated using 0.1N HCl. Real groundwater testing revealed its significantly reduced performance in presence of competing multivalent ions and alkaline pH conditions. However, the same could be partially mitigated through simple pH adjustment. The present study could thus demonstrate pH adjustment as a simple and effective approach for enhancing the overall nitrate removal efficiency and service life of a promising laboratory scale GAC based gravity-driven fixed-bed adsorption system for off-grid settings.</div></div>","PeriodicalId":37879,"journal":{"name":"Groundwater for Sustainable Development","volume":"34 ","pages":"Article 101670"},"PeriodicalIF":5.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148640379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mind the gap: A hydrogeological forecasting-oriented digital twin framework for groundwater levels under sparse irregular sampling","authors":"César de Oliveira Ferreira Silva,&nbsp;Rodrigo Lilla Manzione","doi":"10.1016/j.gsd.2026.101672","DOIUrl":"10.1016/j.gsd.2026.101672","url":null,"abstract":"<div><div>Reliable groundwater-level forecasting is critical for water resources management and early warning in regions where monitoring networks are sparse and irregular. However, most machine-learning and time-series approaches assume regularly sampled observations, limiting applicability under realistic monitoring conditions. This study presents a forecasting-oriented hydrogeological digital twin framework designed for irregular multi-well groundwater observations. Measurements were harmonized onto a monthly grid and augmented with missingness-aware features encoding observation availability and staleness. The framework integrates meteorological forcing, SAFER-derived actual evapotranspiration (<span><math><mrow><mi>E</mi><msub><mrow><mi>T</mi></mrow><mrow><mi>a</mi></mrow></msub></mrow></math></span>), GLDAS root-zone soil moisture, and rolling hydroclimatic indicators representing antecedent recharge and wetness conditions. A global long short-term memory (LSTM) neural network with well embeddings was trained using time-ordered validation and leakage-controlled preprocessing. Forecast skill was evaluated using mean absolute error (MAE), root mean squared error (RMSE), and the coefficient of determination (<span><math><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>). The model achieved stable generalization with training and test RMSE values near 0.42 m, a test MAE of 0.28 m, and a test <span><math><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> of 0.88. Per-well evaluation showed robust performance across heterogeneous monitoring conditions, with larger errors concentrated in wells affected by long observation gaps or abrupt regime shifts. Results demonstrate that explicitly accounting for monitoring irregularity and antecedent hydroclimatic conditions improves groundwater forecasting under severe data scarcity. The proposed framework provides a scalable forecasting-oriented digital twin module for operational groundwater monitoring in data-limited settings.</div></div>","PeriodicalId":37879,"journal":{"name":"Groundwater for Sustainable Development","volume":"34 ","pages":"Article 101672"},"PeriodicalIF":5.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148730336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integration of gravity, magnetic and remotely sensed data for the exploration of potential groundwater zones using Frequency Ratio (FR) and Analytic Hierarchy Process (AHP) in the Benue Division, North Cameroon","authors":"Quentin Marc Anaba Fotze,&nbsp;Charles Antoine Basseka,&nbsp;Anatole Eugene Djieto Lordon,&nbsp;Ghislain Ngassam Mbianya,&nbsp;Abdoul Aboubakar,&nbsp;Marcelin Bikoro Bi Alou,&nbsp;Amina Aboubakar,&nbsp;Mahamat Abakar,&nbsp;Jacques Wassouo Wadjou,&nbsp;Jean Marcel Abate Essi,&nbsp;Jean Paul Sep Nlomngan","doi":"10.1016/j.gsd.2026.101673","DOIUrl":"10.1016/j.gsd.2026.101673","url":null,"abstract":"<div><div>Sustainable groundwater supply remains a perpetual challenge worldwide, especially in semi-arid to arid areas where water availability decreases in space and time. This situation is worsened by climate change and progressive demographic increase. The aim of this study is to produce a reliable map of sustainable groundwater availability in the Benue Division, North Cameroon. Based on the synergistic use of remote sensing, potential field and well data, 11 (eleven) critical factors were weighed and used as thematic layers for groundwater mapping. Both Frequency Ratio (FR) and Analytic Hierarchy Process (AHP) methods were applied. As a result, FR and AHP maps yielded AUC scores of 0.85 and 0.45 for success rate and 0.68 and 0.51 for prediction rate respectively. However, empirical distortions were observed in the statistical computations of the FR model, indicating that this model was strongly influenced by biases in the historical drilling inventory, and suggesting that the AHP model provided more reliable predictions. Accordingly, high groundwater areas are found in the environs of Bamake, Bibemi, Bacheore, Tingori and Gouna. Besides, the 2D geological modelling from two profiles P₁ and P₂ extracted from land Bouguer gravity data, indicated that sustainable groundwater reservoirs may be found at depths ranging from 0 to 500 m, and from 0 to 2160 m for profiles P₁ and P₂ accordingly. This study illustrates a major issue regarding regional groundwater mapping. Data-driven models are completely dependent on the quality of their input well inventories and knowledge-based models remain a vital tool for the assessment of boreholes implantation biases.</div></div>","PeriodicalId":37879,"journal":{"name":"Groundwater for Sustainable Development","volume":"34 ","pages":"Article 101673"},"PeriodicalIF":5.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148640374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flooding and monsoonal recharge generate distinct contaminant mobilization pathways in a shallow floodplain aquifer","authors":"Dorina Murgulet,&nbsp;Cristopher Vickers,&nbsp;Roya Narimani,&nbsp;Mustafa Eissa,&nbsp;Valeriu Murgulet,&nbsp;Ifeanyi Emmanuel Anyanwu,&nbsp;Vikram Kapoor","doi":"10.1016/j.gsd.2026.101664","DOIUrl":"10.1016/j.gsd.2026.101664","url":null,"abstract":"<div><div>Extreme hydroclimatic events, such as hurricanes and monsoon-season rainfall, can dramatically alter groundwater recharge patterns and mobilize contaminants, but the mechanisms that distinguish short-term from sustained impacts on aquifer chemistry remain poorly understood. This study investigated how flooding and prolonged wet-season recharge generate distinct contaminant-mobilization regimes in a sandy floodplain aquifer in South Texas. Groundwater and surface-water quality monitoring occurred across three hydroclimatic periods: post-hurricane flooding, dry season, and the summer monsoon. Field measurements were integrated with geochemical and statistical modeling to evaluate hydrologic and geochemical controls on latent controls on contaminant behavior under contrasting recharge conditions. Results show that flooding triggered rapid, transport-dominated spikes in ammonium, Zn²⁺, and fecal indicators (total coliform, <em>E. coli</em>), whereas the monsoon period was characterized by elevated Pb²⁺ and phosphate, consistent with redox-driven internal processes and sustained hydrologic connectivity. Modeling results further indicated that contaminant dynamics were governed more strongly by recharge persistence, redox evolution, and nutrient interactions than by total rainfall alone. Notably, surface-water–groundwater exchange likely continued well beyond the flood event, challenging the assumption that flood-driven contamination is a short-lived phenomenon. Finally, the co-occurrence of heavy metals, fecal markers, and phosphate in drinking-water flood plain aquifers indicates that exposure risks persist across seasons in infrastructure-limited communities. These findings highlight the need for long-term groundwater monitoring frameworks that account for both rapid event-scale contamination and prolonged wet-season geochemical evolution.</div></div>","PeriodicalId":37879,"journal":{"name":"Groundwater for Sustainable Development","volume":"34 ","pages":"Article 101664"},"PeriodicalIF":5.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148729884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}