Hydrological Processes最新文献

{"title":"Effects of Climate Change on Ecologically Sensitive Flows in the Goulburn River Basin, Australia","authors":"Sudeep Banad,&nbsp;Rajat Choudhary,&nbsp;Yongping Wei,&nbsp;Rupesh Jayaram Patil,&nbsp;C. T. Dhanya","doi":"10.1002/hyp.70666","DOIUrl":"https://doi.org/10.1002/hyp.70666","url":null,"abstract":"<p>Climate change is expected to substantially modify river flow regimes, yet most climate-impact studies have focused on changes in streamflow magnitude without explicitly evaluating ecologically sensitive components of the flow regime that underpin environmental-flow management. This study quantified how projected climate change may alter ecologically sensitive flow characteristics in the regulated Goulburn River, Australia. A calibrated Soil and Water Assessment Tool (SWAT) model was used to simulate daily streamflow using bias-corrected temperature and precipitation projections from five CMIP5 General Circulation Models (GCMs) under Representative Concentration Pathways (RCP4.5 and RCP8.5). Ecologically sensitive flow metrics representing low-flow persistence, seasonal flow magnitude, hydrological variability, and high-flow pulse characteristics were evaluated for two future periods (2030–2050 and 2051–2080) relative to the baseline period (1980–2017). Across multiple climate models and emission scenarios, projected hydrological responses consistently indicated declining low-flow persistence, changes in seasonal-flow magnitude, increased hydrological variability and altered high-flow pulse characteristics, with the magnitude of change generally increasing under the higher-emission RCP8.5 scenario. Collectively, these responses indicate increasing risks to habitat persistence, hydraulic connectivity and ecological processes that depend on predictable flow regimes. By integrating climate projections, process-based hydrological modelling, and biologically informed flow metrics, this study moves beyond conventional discharge-based climate-impact assessments and provides a transferable framework for evaluating climate-change impacts on ecologically sensitive components of river flow regimes, thereby supporting adaptive environmental-flow management in regulated river systems.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 8","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70666","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Attribution of Future Water Stress in a Two-Way Coupled Socioeconomic–Hydrological Framework","authors":"Tetsuya Fukuda,&nbsp;Yuichi Muto,&nbsp;Takao Yoshikane,&nbsp;Tomoko Nitta,&nbsp;Hiroaki Kawata,&nbsp;Kei Yoshimura","doi":"10.1002/hyp.70667","DOIUrl":"https://doi.org/10.1002/hyp.70667","url":null,"abstract":"<p>Water scarcity arises from the complex interplay between socioeconomic water demand and hydrological water availability, yet most global assessments represent these components separately or through one-way coupling. This limits their ability to capture dynamic feedbacks between socioeconomic and hydrological processes. In this study, we developed a two-way coupled socioeconomic–hydrological framework linking the Global Change Analysis Model and the Integrated Land Simulator. The framework dynamically exchanges land-use and hydrological water-availability information between the two models, enabling internally consistent representation of water demand and hydrological water availability through bidirectional feedbacks. We performed century-scale simulations from 2020 to 2100 under SSP1–2.6, SSP2–4.5, SSP3–7.0 and SSP5–8.5, with ILS at 0.5° resolution and Global Change Analysis Model operating over 32 geopolitical regions. Benchmark evaluation showed that the coupled configuration maintained statistically consistent performance in reproducing global water withdrawals and agricultural prices while modestly improving river-discharge consistency. Using this framework, we decomposed future changes in water stress into socioeconomic and hydrological contributions. Across all four Shared Socioeconomic Pathways and Representative Concentration Pathways scenarios, roughly 80% of global geopolitical sub-basin area exhibits increases in water stress. Areas where hydrological change is the dominant contribution account for about 20% under SSP1–2.6 and SSP2–4.5, rising to roughly 30% under SSP3–7.0 and SSP5–8.5. Regionally, Africa's future water-stress intensification remains largely socioeconomic because of sustained demand growth, whereas Central Asia increasingly exhibits hydrologically driven water stress as water availability declines. These results demonstrate that future water scarcity cannot be explained by climate or socioeconomic demand alone, but is shaped by coupled socioeconomic–hydrological feedbacks. The proposed framework provides a foundation for dynamic, region-specific water resources management under future Shared Socioeconomic Pathways and Representative Concentration Pathways scenarios.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 8","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70667","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tides of the Midland: From Groundwater Into the River","authors":"Andrei-Emil Briciu","doi":"10.1002/hyp.70664","DOIUrl":"https://doi.org/10.1002/hyp.70664","url":null,"abstract":"<p>The existence of the groundwater tides generated under the action of the earth and atmospheric tides was well documented during the last 100 years. In the last decade, other studies highlighted that the tidal signal is further transmitted from groundwater into rivers located inland, where no oceanic tide propagates. Although this signal, especially as a semidiurnal oscillation, was measured using various parameters, the available data did not yet allow a precise identification of the point where the signal is transferred from groundwater into a stream. Here we show the tidal oscillations of the missing link between the two environments. The water level time series of Antelope Spring (in Oklahoma) have significant M2 and S2 (semidiurnal tidal components) with a cumulated amplitude of up to 2.1 cm from a karst aquifer. The semidiurnal oscillations of the spring are in phase with the same type of oscillations in the gravitational acceleration and have the highest amplitudes during New Moon and Full Moon. These findings have important theoretical implications in predicting high resolution hydrographs.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 8","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70664","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interannual Variability of Streambed Hydraulic and Solute Transport Properties Quantified Using Mixed-Effects Models","authors":"Tanzila Ahmed,&nbsp;Dawn VanLeeuwen,&nbsp;Ruba A. M. Mohamed,&nbsp;Scott C. Brooks,&nbsp;Mohamad Reza Soltanian,&nbsp;Jesus D. Gomez-Velez,&nbsp;Kenneth C. Carroll","doi":"10.1002/hyp.70648","DOIUrl":"https://doi.org/10.1002/hyp.70648","url":null,"abstract":"<div>\u0000 \u0000 <p>Streambed sediment transport, scour and deposition create spatiotemporal variability in streambed properties, contributing to uncertainty in hyporheic zone characterization. Accurate statistical characterization of this variability is further complicated by spatial dependence among measurements, which must be explicitly accounted for. To examine the potential effects of mobile sediments on streambed characterization, this study evaluated year-to-year changes in streambed properties including point measurements of streambed hydraulic conductivity (<i>K</i>_<i>v</i>), hydraulic head gradients, seepage flux, and dissolved mercury (<i>Hg</i>) stream concentration and mass flux (of <i>Hg</i> into the stream) along a reach of East Fork Poplar Creek in Tennessee, USA, over three consecutive years under baseflow conditions. Anomalously high streamflow events were recorded prior to the 2019 measurements, contributing to year-over-year changes in streambed properties. Mean log-transformed <i>K</i>_<i>v</i> and inverse-square-root-transformed Hg concentration differed significantly among years, with 2019 measurements having a lower mean than those from 2017 and 2018. A comparison between a one-dimensional spatial mixed-effects model and a model assuming independence showed that ignoring spatial autocorrelation led to downwardly biased standard error estimates and inflated statistical significance. Standard errors (SEs) from models that accommodate spatial autocorrelation can be substantially larger than those from models that assume independence. This study highlights both the temporal sensitivity of streambed properties to hydrological disturbance and the importance of using statistical frameworks that explicitly account for spatial dependence when evaluating changes in hyporheic exchange and contaminant transport.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 8","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Green Infrastructure as a Climate Shield: Nonlinear Flood Response and Extremes Saturation in a Tropical Andean Urban Watershed","authors":"Joseph Sánchez-Balseca,&nbsp;Agustí Pérez-Foguet,&nbsp;Bolivar Erazo","doi":"10.1002/hyp.70662","DOIUrl":"https://doi.org/10.1002/hyp.70662","url":null,"abstract":"<div>\u0000 \u0000 <p>Assessing flood risk under climate change in data-scarce tropical mountain watersheds requires transparent, reproducible frameworks that explicitly address methodological uncertainties. This study introduces an integrated methodology to evaluate green infrastructure's hydrological role across land-cover and climate scenarios. It combines Coupled Model Intercomparison Project Phase 6 (CMIP6) projections with Quantile Mapping bias correction, Generalized Extreme Value (GEV) analysis, physically informed intensity–duration–frequency (IDF) curve development, and spatially explicit Hydrologic Engineering Center–Hydrologic Modeling System (HEC-HMS). Designed for regions with limited gauging infrastructure, the framework leverages satellite-derived precipitation from the Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS), open-access climate data. Applied to the Güanguiltagua Metropolitan Park in Quito, Ecuador, the approach reveals context-specific responses: under projections from the Max Planck Institute Earth System Model version 1.2 Low Resolution (MPI-ESM1-2-LR), extreme events (return periods <i>T</i> ≥ 50 years) exhibit a saturation signal converging towards ~95 mm/day—a pattern consistent with documented shifts in Andean convective regimes yet contingent on model resolution and requiring validation with convection-permitting simulations. Critically, conservation of natural cover (Curve Number, CN = 45) consistently reduces peak flows by 73%–85% across all scenarios and return periods, demonstrating green infrastructure's dependable buffering capacity. Urbanized sub-basins (CN = 85) show minimal climate sensitivity, underscoring persistent vulnerability. Findings are explicitly contextualized within methodological constraints (single general circulation model [GCM], coarse resolution, Soil Conservation Service Curve Number [SCS-CN] assumptions), avoiding overgeneralization. The framework's modular design enables adaptation across Global South contexts, offering a transparent template for region-specific flood risk assessment where climate projections and green infrastructure intersect.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 8","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148647850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stream Chemistry Responses to Bark Beetle Disturbance and Changing Atmospheric Deposition in Alpine and Forest Headwater Catchments","authors":"Charles C. Rhoades,&nbsp;Timothy S. Fegel,&nbsp;Allison E. Rhea,&nbsp;Banning Starr,&nbsp;Kelly Elder","doi":"10.1002/hyp.70644","DOIUrl":"https://doi.org/10.1002/hyp.70644","url":null,"abstract":"<div>\u0000 \u0000 <p>The extent of alpine land cover influences the chemistry of streams draining mountain catchments and may determine how they respond to ecosystem change. During the first two decades of the 2000s, the Southern Rockies, USA, experienced both severe bark beetle infestation and significant decreases in atmospheric nitrogen (N) and sulfur (S) deposition. To evaluate the consequences of these events, we compared the chemistry of samples collected during 2004–2006 and 2017–2019 in streams draining 18 headwater catchments comprised of mixtures of forest and alpine land cover. Stream total dissolved N, nitrate, and sulfate concentrations increased linearly with the proportion of alpine cover within the study catchments. Consistent with regional patterns in atmospheric deposition, stream nitrate decreased and ammonium increased, though stream sulfate was unchanged. Differences in solute concentrations between the sampling periods were greatest in catchments with the highest proportion of alpine cover and were minimal in fully forested catchments. This relationship demonstrates the sensitivity of catchments with alpine headwaters to changing nutrient deposition and, conversely, the capacity for nutrient retention by non-host vegetation to buffer the impacts of beetle-related tree mortality in fully forested catchments.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 8","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148616369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Runoff, Sediment Yield and Shear Strength Characteristics of Slopes With Different Degradation Types of Alpine Grasslands in the Yellow River Source Region","authors":"Huatan Li,&nbsp;Changyi Liu,&nbsp;Xiasong Hu,&nbsp;Yanhe Wang,&nbsp;Zelei Wang,&nbsp;Yonghui Feng,&nbsp;Shuaifei Li,&nbsp;Yingxiao Zhao","doi":"10.1002/hyp.70651","DOIUrl":"https://doi.org/10.1002/hyp.70651","url":null,"abstract":"<div>\u0000 \u0000 <p>The Yellow River source region, a critical component of the Qinghai-Tibet Plateau (QTP), plays an essential role in regional ecosystems and hydrological cycles. This study investigated the hydrological and mechanical effects of varying degrees of degradation of grassland slopes under rainfall conditions in the Yellow River source region, aiming to elucidate the impacts of grassland degradation on slope runoff generation, sediment yield, and soil stability. Field-simulated rainfall experiments and laboratory direct shear tests were conducted to examine the hydrological responses and mechanical properties of root-soil composites on lightly, moderately, and severely degraded grassland slopes (LDS, MDS, and SDS) under rainfall intensities of 40 mm·h⁻¹ and 80 mm·h⁻¹. The results demonstrated that with increasing degradation severity, the initial runoff time significantly decreased, while both runoff volume and sediment yield increased markedly. At a rainfall intensity of 40 mm·h⁻¹, the average runoff rates for LDS, MDS, and SDS were 0.281 L·min⁻¹, 0.344 L·min⁻¹, and 0.518 L·min⁻¹, respectively. These rates increased to 1.391 L·min⁻¹, 1.710 L·min⁻¹, and 2.154 L·min⁻¹, respectively, under the higher rainfall intensity of 80 mm·h⁻¹. The sediment yield was positively correlated with the degree of degradation; at 80 mm·h⁻¹, the peak sediment yield of severely degraded grassland reached 5.924 g·min⁻¹, which was 9.3 times greater than that of lightly degraded grassland, with a cumulative sediment yield of 292.694 g, which was 10.07 times greater. Furthermore, rainfall significantly increased the moisture content of the shallow soil layer, reducing the shear strength of the soil. Post-rainfall, the shear strength of the shallow soil layer (0–20 cm) decreased significantly, with cohesion reductions of 48.47% for lightly degraded grasslands and 35.42% for severely degraded grasslands, whereas the deep soil layer (40–60 cm) presented no significant change in cohesion, underscoring the critical role of vegetation roots in maintaining shallow soil stability. The synergistic effect of vegetation's three-dimensional structure (canopy-litter-root system) established a hierarchical rainwater regulatory mechanism in slope hydrology, providing vital theoretical and practical insights for soil and water conservation and ecological restoration in the Yellow River source region.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 8","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148616622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Potential Warming-Induced Changes in Stream Water Sources Between Proglacial and Non-Glacial Streams, South-Central Alaska","authors":"H. K. Richardson,&nbsp;A. J. Bergstrom,&nbsp;J. C. Koch,&nbsp;Z. A. Frederick,&nbsp;J. B. Shanley,&nbsp;E. H. Baker","doi":"10.1002/hyp.70654","DOIUrl":"https://doi.org/10.1002/hyp.70654","url":null,"abstract":"<p>Snow and ice-melt are essential for global water resources. Rising air temperatures are causing vegetation encroachment and shrubification of previously snow- and ice-covered landscapes, and precipitation regimes are changing. Collectively, these changes will likely affect the hydrology of mountain environments, although the exact ways in which the hydrology will change are poorly understood. Changing source waters (i.e., the proportion of ice-melt, snowmelt, rain and groundwater) affect the timing and magnitude of streamflow and affect stream temperature, sediment, solute and nutrient fluxes. We investigate spatial and seasonal source water contributions across sub-watersheds of the Nellie Juan River watershed on Alaska's Kenai Peninsula, which differ in glacier cover, elevation and land cover, using a space-for-time approach. To do so, we use a three-endmember mixing model to quantify the contribution of rain, snow/ice-melt and deep groundwater. We show that snow/ice-melt peak later in proglacial streams compared to non-glacial streams. Endmember contributions in non-glacial streams generally vary with elevation and season. We also found that groundwater is a major contributor to streamflow across the study area, contributing between 12% and 47% seasonally, and may become increasingly important as snowpack and ice-melt decrease. This research characterises the shift from a glacierised to a deglaciating landscape through the lens of source water contribution. Broadly, these findings could help improve understanding of how water resources in glacierised watersheds are affected by warming air temperatures.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 8","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70654","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148616467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vertical Unsaturated Flow Governs Storm Runoff Responses: Observational and Theoretical Foundations","authors":"Makoto Tani,&nbsp;Roy C. Sidle,&nbsp;Takahiro Sayama,&nbsp;Yuki Matsushi,&nbsp;Nagahiro Kojima","doi":"10.1002/hyp.70627","DOIUrl":"https://doi.org/10.1002/hyp.70627","url":null,"abstract":"<p>The old water paradox is difficult to resolve based on the traditional runoff mechanism consisting of a downslope flow system that includes overland and subsurface flows. Our observations and theoretical studies revealed that rainfall-runoff responses are governed by vertical unsaturated flow augmenting shallow groundwater that is subsequentially drained by rapid preferential flow. This mechanism explains the physical basis for runoff-storage relationship models and enables the evaluation of the sensitivity of peak runoff rates to soil properties and soil-layer depth. This commentary discusses the development of preferential flow pathways from a geomorphologic perspective and provides information for developing calibration-free, physically-based runoff models in which parameters can be estimated from measurable field indicators.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 7","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70627","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148463172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating Traditional Hydrogeology and Radon-222 to Characterize Groundwater Loss to the Sea in a Peri-Urban Coastal Aquifer in Argentina","authors":"Carretero Silvina,&nbsp;Rapaglia John,&nbsp;Rodrigues Capítulo Leandro,&nbsp;Sánchez Caro Leonardo,&nbsp;Kruse Eduardo","doi":"10.1002/hyp.70638","DOIUrl":"https://doi.org/10.1002/hyp.70638","url":null,"abstract":"<div>\u0000 \u0000 <p>Coastal freshwater resources are increasingly vulnerable as climate warming and altered precipitation patterns intensify stress on low-lying sandy aquifers, particularly in rapidly urbanizing regions. Reduced rainfall, higher evaporation and growing water demand from tourism and population expansion limit recharge. In Latin America, where many major cities lie along the coast and impervious surfaces continue to increase, understanding hydrological pathways is essential to evaluate freshwater availability under rising environmental pressures. An often overlooked component of coastal water budgets is submarine groundwater discharge (SGD), the subsurface flow of groundwater into the sea. While recirculated saline SGD has limited impact on freshwater reserves, the freshwater fraction (fSGD) represents a true loss from aquifers; its omission from recharge–runoff assessments leads to systematic overestimation of groundwater availability, especially in sandy coastal barriers with minimal surface water storage. This study investigates groundwater transport and SGD dynamics in the sandy coastal aquifer of Buenos Aires Province, Argentina, using a combined approach based on ²²²Rn activity and hydrogeological parameters. ²²²Rn concentrations were measured in wells and along a nearshore transect ~200 m from the shoreline, complemented by groundwater depth, electrical conductivity, temperature and contour maps. No significant correlations were observed between ²²²Rn and electrical conductivity, temperature, groundwater depth, geomorphology, or unsaturated zone thickness. ²²²Rn showed an inverse relationship with the precipitation regime, and sectors previously affected by marine intrusion exhibited the lowest activities. Comparisons of SGD estimates revealed that radon-based values exceeded hydrodynamic calculations in several areas, and vegetation emerged as a potential control on ²²²Rn behaviour. Conservative estimates derived from Darcy's calculations indicate that approximately 15% of total available freshwater is lost to the sea via SGD. These findings underscore the need to incorporate fSGD into coastal freshwater assessments and to further investigate ecohydrogeological processes influencing SGD under increasing climatic and anthropogenic stress.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 7","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148466607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}