Journal of Hydrology最新文献

{"title":"Long-term monitoring of a high-energy beach using joint salinity-based inversion of different ERT and sampling data","authors":"Nico Skibbe ,&nbsp;Thomas Günther ,&nbsp;Rena Meyer ,&nbsp;Mike Müller-Petke","doi":"10.1016/j.jhydrol.2026.135034","DOIUrl":"10.1016/j.jhydrol.2026.135034","url":null,"abstract":"<div><div>High-energy beaches represent dynamic biochemical reactors at the boundary between land and sea, driven by salinity changes. We study the temporal dynamics of the saltwater-freshwater distribution on the North beach of Spiekeroog, Germany, over a period of 18 months by continuous logging of porewater salinity in multi-level monitoring wells, campaign-based direct-push measurements of porewater salinity, a quasi-continuously measuring electrode chain and repeated ERT measurements both obtaining the bulk electrical conductivity (<span><math><mi>E</mi><msub><mi>C</mi><mi>b</mi></msub></math></span>). Instead of handling each data type independently and in particular converting the inversion results of the <span><math><mi>E</mi><msub><mi>C</mi><mi>b</mi></msub></math></span> of the ERT measurements into the salinity, we analyze all data jointly and directly invert for salinity. With this approach we can also add measured fluid electrical conductivity (<span><math><mi>E</mi><msub><mi>C</mi><mi>f</mi></msub></math></span>) data directly into the salinity inversion. Furthermore we derive a simple model for the formation factor from direct comparison of <span><math><mi>E</mi><msub><mi>C</mi><mi>b</mi></msub></math></span> and <span><math><mi>E</mi><msub><mi>C</mi><mi>f</mi></msub></math></span>. As the temperature distribution in the subsurface plays a crucial role in deriving salinity from <span><math><mi>E</mi><msub><mi>C</mi><mi>b</mi></msub></math></span>, it needs to be measured and incorporated in the inversion. This approach proves superior to classic workflows. As a result, we are able to study the dynamics of subterranean estuaries at depth and provide 2D images of the seasonal change and extent of the upper saline plume and observe how remnants of winter storm floods penetrate into the subsurface throughout the year. These findings are useful for calibrating groundwater models and improving our understanding of the deeper salinity dynamics as they provide a salinity distribution directly as one of the input parameters of such models.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"669 ","pages":"Article 135034"},"PeriodicalIF":6.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time-series hydrochemical analysis of an interwell flow test through a fractured aquifer and comparison against microbial community data","authors":"Yuran Zhang ,&nbsp;Xiaoxuan Li ,&nbsp;Adam J. Hawkins ,&nbsp;Yiman Li ,&nbsp;Qian Zhang ,&nbsp;Tianming Huang ,&nbsp;Zhonghe Pang ,&nbsp;Anne E. Dekas ,&nbsp;Roland N. Horne","doi":"10.1016/j.jhydrol.2026.135093","DOIUrl":"10.1016/j.jhydrol.2026.135093","url":null,"abstract":"<div><div>Characterizing the geochemical processes during interwell flow through a fractured rock mass is helpful in understanding how geological reservoirs respond to fluid injection/production and how they can be better managed. In this work, we analyzed weekly time-series hydrochemistry data from a 10-month injection test through the EGS Collab Experiment-1 testbed, a well-characterized 1478-m-deep fractured metasedimentary rock formation located at the Sanford Underground Research Facility in Lead, South Dakota, USA. Exogenous low-salinity water was injected into the formation through one well, resulting in water production from four wells/intervals. Results revealed distinct spatiotemporal patterns in hydrochemical evolution in each water-producing well, highlighting the heterogenous nature of flowpaths in this fractured crystalline-rock formation. Mixing model analysis revealed evolving contributions from pre-existing formation water and an additional source of particular ions attributed to chemical reactions. Ionic ratio analysis combined with knowledge of local lithology pointed to specific reactions that may have occurred. Finally, hydrochemical data was compared to previously published microbial community history data collected simultaneously during the same flow test. It was found that hydrochemical and microbial data yield consistent interpretations on interwell flow. However, the between-sample chemical similarity is not coincident with microbial similarity, and the latter has much higher resolution when used as a natural “barcode”. We pointed out the complementary strengths of the two data types, whereby hydrochemical data has well-understood reactive/transport properties hence easily modeled, and microbial data has higher resolution due to its immense diversity. Our findings highlight the benefits of a combined hydrochemical/microbial analysis in reservoir monitoring.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"669 ","pages":"Article 135093"},"PeriodicalIF":6.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146135289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the limits of two lumped hydrological models through divergences between daily and sub-daily projections","authors":"Virginie Destuynder,&nbsp;Siavash Pouryousefi Markhali,&nbsp;Annie Poulin","doi":"10.1016/j.jhydrol.2026.135081","DOIUrl":"10.1016/j.jhydrol.2026.135081","url":null,"abstract":"<div><div>The present paper identifies four common reasons for divergences between projections of flow metrics simulated by lumped conceptual hydrological models at a daily time step, and a daily-averaged 3-h time step. These reasons are based on five case studies simulated by two hydrological models in North America in the context of climate change, and are related to: the filtering of subdaily discrete and cyclic processes; the time-step dependent solving of nonlinear equations involving logical conditions; the time-step dependent solving of nonlinear sequential equations; and the timing of the flood events within the daily window. The time-step dependent simulation of the corresponding internal processes requires compensatory mechanisms in other processes in order to achieve an equivalent performance of the hydrological models in calibration at both time steps. These compensatory mechanisms can be identified in the parameter sets of the models and often imply a time-step dependent seasonality of the internal variables. Divergences between hydrological projections at daily and subdaily time steps reveal significant future shifts in the hydrological regime or in the runoff-generating processes, outside the domain of validity of the calibrated parameter sets. Time-step dependent projections underscore the need for detailed insight before using projections for engineering applications. Furthermore, the comparison of hydrological simulations from different time steps is a valuable approach to assess the domain of validity of calibrated parameter sets, and to understand the behavior of conceptual hydrological models under non-stationary climate conditions.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"669 ","pages":"Article 135081"},"PeriodicalIF":6.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extreme precipitation in eastern China: a centennial-scale analysis across multiple river basins based on return period thresholds","authors":"Yichen Yang ,&nbsp;Hanwei Yang ,&nbsp;Yue Ma ,&nbsp;Yong Zhao ,&nbsp;Yuanbiao She ,&nbsp;Chikun Luo","doi":"10.1016/j.jhydrol.2026.135058","DOIUrl":"10.1016/j.jhydrol.2026.135058","url":null,"abstract":"<div><div>Under global warming, China has experienced frequent extreme precipitation events, with growing spatial disparities among various river basins. Traditional methods for identifying extreme precipitation based on percentile thresholds (PTs; e.g., R95p or R99p) have proven insufficient sensitivity in responding to changes in precipitation extremes. This study introduces “return period thresholds” (RPT) from hydrology for extreme precipitation definition and verifies their superior sensitivity via comparative analysis in six major eastern Chinese river basins. Defining heavy and extreme heavy precipitation by 0.5a and 2a return periods, respectively, RPT better reflects actual changes in extreme precipitation than PT. For instance, an upward trend in extreme precipitation has been observed throughout the Songhua River Basin, the central and southern Huai River Basin and the middle reaches of the Yangtze River Basin, consistent with the meridional tripolar pattern (8–10a interdecadal oscillations) of the first mode of Empirical Orthogonal Function (EOF). The second mode (EOF2) displays a southward-shifted dipole structure with dominant 5–6a cycles, historically correlated with flood occurrences. Projections to 2100 indicate an upward trajectory in thresholds across all basins, with two salient characteristics: larger absolute increases in southern compared to northern basins, and faster growth rates for extreme heavy precipitation relative to heavy precipitation. These findings underscore the need for enhanced monitoring of both the frequency and intensity of extremes, particularly within southern basins.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"669 ","pages":"Article 135058"},"PeriodicalIF":6.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards cooperation on transboundary rivers: achieving a win–win balance between upstream hydropower generation and downstream water demand under climate change","authors":"Tesfalem Abraham ,&nbsp;Tunde Olarinoye ,&nbsp;Andreas Hartmann ,&nbsp;Harrie-Jan Hendricks Franssen ,&nbsp;Yan Liu","doi":"10.1016/j.jhydrol.2026.135111","DOIUrl":"10.1016/j.jhydrol.2026.135111","url":null,"abstract":"<div><div>Transboundary river management is critical for international relations, sustainable energy development, and ecosystem management. Hydropower development, while meeting downstream water demand, is crucial for fostering cooperation among countries sharing water resources. However, addressing this challenge under the context of climate change poses significant complexities. This study investigates the cooperation regarding hydropower production and water releases under the potential impact of climate change. We project future streamflow by the calibrated HBV hydrological model in three transboundary rivers originating from Ethiopia: the Upper Blue Nile (UBN), Omo, and Tekeze rivers. Subsequently, we compute the hydropower potential (maximum hydropower energy within a specific period) by optimizing water release policies using the adapted ’Reservoir’ R package. The hydropower potential and water release are analyzed based on 11 scenarios of water releases ranging from favoring the upstream country (Scenario 1) to benefiting downstream countries (Scenario 11) for the three example dams on the studied transboundary rivers: the Grand Ethiopian Renaissance Dam (GERD), Omo-Gibe III, and Tekeze dams. Our focus lies in identifying the cooperation ranges that provide optimal hydropower in the upstream and water release to the downstream among the varying water release policies within this scenario spectrum. The findings indicate that within an appropriate range for the minimum monthly water release threshold, the hydropower potential for the three study sites only has a small decrease, while the water release to downstream, especially for the driest month, can be 1.14–2.45 times larger compared to no water release constraints. For GERD and Omo-Gibe III, maintaining the monthly water release threshold of 30%-50% of the monthly flow is assumed to define the cooperation range in the historical periods. However, for Tekeze, the cooperation range is from 20% to 40% of the monthly water release. Due to climate change, the cooperation range for GERD and Omo-Gibe III is projected to decrease to 20–30% in future periods, whereas no significant impact is expected for Tekeze. The study reveals that future energy production of the hydropower dams on the transboundary rivers are influenced by the monthly minimum water release threshold, underscoring the need for adaptive cooperative strategies for both upstream and downstream countries in the face of climate change.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"669 ","pages":"Article 135111"},"PeriodicalIF":6.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146153059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient simulation of landslide-induced surges and control effects of different position piles based on an improved flow-flow model","authors":"Zhangqing Wang ,&nbsp;Yong Wu ,&nbsp;Yongjie Zhao ,&nbsp;Yingpeng Wang ,&nbsp;Siming He ,&nbsp;Xinpo Li ,&nbsp;Lei Zhu","doi":"10.1016/j.jhydrol.2026.134944","DOIUrl":"10.1016/j.jhydrol.2026.134944","url":null,"abstract":"<div><div>The two-layer fluid model is one of the most efficient methods for simulating the landslide into the water process. However, the landslide equations in the model overlook the viscosity coefficient and make certain assumptions in their derivation from the NS equations, which results in the simulator being less able to describe different flow-state disasters, or solid structures, and failing to simulate landslide-induced surges effectively while considering their interaction with the prevention structure within a unified fluid framework. Therefore, based on our previous study of the numerical origin of the inviscid defect in the SH model and the enhanced SH model proposed, from the perspective of fluid–fluid interaction, an improved flow-flow coupling model suitable for landslide surge and its prevention is proposed, which not only characterizes landslides with different flow states and describing solid control structures, but also efficiently realizes the analysis of landslide evolution, surge generation and its interaction with control structure piles under a unified fluid framework. In addition, for the cross-scale impact of landslide and surge on the pile and extensive calculation, the discrete solution of the new flow-flow model employs a limited volume method combined with the local mesh refinement technology. By setting multiple sets of examples, the study further carries out the simulation results of the new model. It improves the ability to calculate the interaction between landslides and pile-water bodies. It clarifies the preventive and treatment effects of different space layouts of pile groups on surges, proving that this technology is excellent for risk assessment. Finally, through the preview of the Sichuan Bageduzhai landslide-induced surge Incident, the study confirms that the improved model supports the reliability of disaster prediction and structural interactions, as well as the development of disaster computing and prevention technology.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"668 ","pages":"Article 134944"},"PeriodicalIF":6.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145957164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global quantification of the bidirectional dependence between vegetation productivity and multi-layer soil moisture","authors":"Ying Liu,&nbsp;Jiumeilin Shi,&nbsp;Hui Yue,&nbsp;Xu Wang","doi":"10.1016/j.jhydrol.2026.135065","DOIUrl":"10.1016/j.jhydrol.2026.135065","url":null,"abstract":"<div><div>Soil moisture serves as a crucial water source for vegetation growth, while vegetation dynamics in turn regulate soil moisture through processes such as evapotranspiration and canopy interception. Quantitatively characterizing this mutual feedback is essential for optimizing hydrological processes and promoting coordinated vegetation–water management. However, the bidirectional interactions between soil moisture and vegetation productivity across different climate zones, vegetation types, and soil depths remain poorly understood. Based on Global Solar Induced Chlorophyll Fluorescence, soil moisture, the average air temperature at 2 m, and solar radiation datasets, this study employed trend analysis, causal inference, and multiple linear regression to explore the Granger causality between vegetation productivity and multi-layer soil moisture under different environmental conditions. Results revealed widespread bidirectional dependence between vegetation productivity and soil moisture across all soil layers, with interaction strength declining from 79.84% in the surface layer (0–10 cm) to 72.04% in the deep layer (100–200 cm). The magnitude of this bidirectional coupling varied significantly across climate zones: dependence peaked in surface soils within temperate regions (82.52%), while tropical zones exhibited maxima in the shallow (82.99%) and deep (78.05%) layers. Boreal zones showed the strongest dependence in the middle soil layer (76.25%). Furthermore, driven by differences in transpiration rates and water retention capacity, woody plants demonstrated higher average bidirectional dependence (79.4%) than herbaceous plants (75.75%), whereas shrubland vegetation exhibited relatively lower dependence (74%). Considering the spatial distribution of climate and vegetation types, tropical zones (dominated by evergreen broadleaf forests) and boreal zones (dominated by shrublands) both showed peak bidirectional dependence in the shallow soil layer. Other climate zones, primarily influenced by grassland vegetation, exhibited peak dependence within the surface soil layer. This study reveals the variability in bidirectional dependence between vegetation productivity and multilayer soil moisture across different climatic zones and vegetation types, which will provide a robust theoretical foundation for improving regional soil moisture regulation and guiding ecosystem restoration under changing climatic conditions.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"669 ","pages":"Article 135065"},"PeriodicalIF":6.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated multi-scale ecohydrogeological monitoring of spatio-temporal dynamics in karst critical zones","authors":"Nataša Ravbar ,&nbsp;Metka Petrič ,&nbsp;Mitja Ferlan ,&nbsp;Uroš Novak ,&nbsp;Janez Kermavnar ,&nbsp;Lado Kutnar ,&nbsp;Aleksander Marinšek ,&nbsp;Daniel Žlindra ,&nbsp;Blaž Kogovšek ,&nbsp;Erika Kozamernik ,&nbsp;Cyril Mayaud ,&nbsp;David Štefanič ,&nbsp;Sara Skok ,&nbsp;Janez Mulec ,&nbsp;Stanka Šebela ,&nbsp;Urša Vilhar","doi":"10.1016/j.jhydrol.2026.135027","DOIUrl":"10.1016/j.jhydrol.2026.135027","url":null,"abstract":"<div><div>Contemporary environmental concerns highlight the vulnerability of karst environments to changing hydrometeorological patterns and vegetation disturbance, necessitating a unified, interdisciplinary strategy for comprehensive understanding. This paper critically examines the current state of research. To overcome the identified gaps, it presents an integrated multi-scale ecohydrogeological monitoring approach tailored to karst critical zones (KCZ) and its spatio-temporal variability. Forested karst aquifer in Slovenia is used as a case study to demonstrate and assess the strengths and limitations of the proposed monitoring framework. To decipher flow dynamics and propose customized data collection strategies the approach combines surface and underground sites and employs advanced methods adapted to the challenges of karst environments. The results highlight the benefits and advancements of monitoring and sampling approaches to ensure representativeness in heterogeneous environments. The focus is on the use of enhanced precipitation monitoring systems to expand sampling areas nearly fivefold and improve precipitation and throughfall measurements. Additionally, customized lysimeter techniques for karst soils and microscale adaptations for cave exploration have been developed, addressing the challenges of instrument placement in environments with significant variability. Further opportunities lie in improving instrument protection, integrating sensor networks, combining remote sensing and scaling from plot to aquifer level. However, challenges remain in achieving spatio-temporal representativeness and ensuring the operational reliability of snow monitoring, soil solution sampling and drip flow measurements. Threats include environmental pressures and hydrometeorological conditions, equipment tampering and funding stability. Nevertheless, this comprehensive approach improves monitoring of ecohydrogeological processes in the KCZ, promotes interdisciplinary collaboration and environmental resource management.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"669 ","pages":"Article 135027"},"PeriodicalIF":6.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"D2Mamba: A mamba-based method for floodway obstructions segmentation from multispectral satellite imagery","authors":"Shiyang Fu ,&nbsp;Zhujun Gu ,&nbsp;Yuebin Wang ,&nbsp;Liqiang Zhang ,&nbsp;Haiyan Gu ,&nbsp;Jiasheng Wu ,&nbsp;Guanghui Liao","doi":"10.1016/j.jhydrol.2026.135069","DOIUrl":"10.1016/j.jhydrol.2026.135069","url":null,"abstract":"<div><div>Floodway obstructions are critical anthropogenic factors that exacerbate flood risks, playing a key role in flood control and ecological protection. Current obstruction extraction methods face two main limitations. First, high-resolution visible-light imagery is highly sensitive to lighting and terrain, which restricts its applicability in complex hydrological environments. Second, most methods cannot capture precise obstruction boundaries and fail to meet the fine-grained requirements of floodway management. To address these challenges, we propose D2Mamba, an automated obstruction extraction framework. The method first uses a dual-domain Mamba block (DDMB) to extract key obstruction features. It then employs an adaptive feature fusion module (AFFM) that uses attention mechanisms to fuse encoder features at the same level, enhancing representation capabilities. To balance dual-domain feature learning, we designed a dual-domain loss function (DLoss) to constrain joint optimization of spatial and frequency domain features. To evaluate the effectiveness of the proposed D2Mamba, we constructed a multispectral floodway obstructions dataset (MFOD), including 8301 images and corresponding masks. Comprehensive experiments showed that D2Mamba outperformed 15 state-of-the-art (SOTA) methods on MFOD, with F1, IoU, and OA exceeding other methods by 0.14–14.25%, 3.05–24.47%, and 0.05–14.78%, respectively. Furthermore, the proposed method also demonstrated robust adaptability in large-scale obstruction extraction within the Datengxia area.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"669 ","pages":"Article 135069"},"PeriodicalIF":6.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemical dynamics and colloidal transfer of major and trace elements in the Hers-Mort − Girou watershed: distinction between natural and anthropogenic signatures evidenced by REE anomalies","authors":"Baptiste Alran ,&nbsp;Eva Schreck ,&nbsp;Rémy Berrabah ,&nbsp;Oleg S. Pokrovsky ,&nbsp;Aubin Yettou ,&nbsp;Jérôme Viers","doi":"10.1016/j.jhydrol.2026.134981","DOIUrl":"10.1016/j.jhydrol.2026.134981","url":null,"abstract":"<div><div>Small watersheds are highly sensitive to anthropization, which deeply alters elemental biogeochemical cycles. This study focuses on the Hers-Mort and Girou watersheds near Toulouse (SW France), originating in the rural Lauragais region. A sampling campaign in January 2025 combined laboratory ultrafiltration (0.22 μm, 0.025 μm, 3 kDa) with measurements of physicochemical parameters (conductivity, pH, alkalinity) and elemental concentrations (DOC, anions, major cations, and trace elements).</div><div>Results reveal a clear distinction between natural and anthropogenic signals. Linear relationships between carbonates, nitrates, and Ca–Mg highlight the dominant role of lithology, with carbonate dissolution naturally supplying major cations, further enhanced by nitrates. Ultrafiltration showed that most elements occur in the labile low-molecular-weight &lt;3 kDa (LMW &lt;3 kDa) fraction, indicating high potential bioavailability and little downstream variation in DOC, Fe, Mn, Cu, and As.</div><div>Conversely, Zn and Gd displayed strong co-variation in their colloidal patterns, with the &lt;3 kDa fraction increasing downstream in parallel with urbanization, reaching up to 80 % in the most impacted areas. These elements thus represent robust tracers of anthropogenic influence. Rare Earth Element (REE) patterns in headwaters were controlled by molassic lithology, whereas downstream sections showed pronounced positive Gd anomalies (0.89–25) and systematic LREE depletion with HREE enrichment. Anthropogenic Gd accounted for 10–90 % of total Gd, evidencing clear artificial inputs and the progressive shift from natural to anthropogenic geochemical dynamics.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"668 ","pages":"Article 134981"},"PeriodicalIF":6.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146015014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}