Anna Joelle Greife,Elisa Calamita,Monica Pinardi,Laura Carrea,Ross I. Maidment,Jaime Pitarch,Mzime Regina Ndebele‐Murisa,Claudia Giardino,Mariano Bresciani,Francesco Pietro Fava,Clément Albergel,Marina Amadori
{"title":"Effects of Reduced Precipitation and Water Level Variability on Phytoplankton Dynamics and Thermal Structure in a Large Tropical Reservoir","authors":"Anna Joelle Greife,Elisa Calamita,Monica Pinardi,Laura Carrea,Ross I. Maidment,Jaime Pitarch,Mzime Regina Ndebele‐Murisa,Claudia Giardino,Mariano Bresciani,Francesco Pietro Fava,Clément Albergel,Marina Amadori","doi":"10.1029/2026wr043749","DOIUrl":"https://doi.org/10.1029/2026wr043749","url":null,"abstract":"Abstract Drought is one of the most severe and complex natural hazards causing changes in water balance and impeding crucial water‐dependent ecosystem services. Over the last 25 years, multiple severe droughts linked to El Niño events have affected the Zambian and Zimbabwean regions. As a result, Lake Kariba, world's largest artificial reservoir by volume, saw historically low water levels and power shortages from reduced hydropower generation. This study employs a novel integrated approach to investigate the effects of varying water levels on the spatio‐temporal dynamics of phytoplankton blooms across the lake, combining remote sensing, in situ measurements, and a three‐dimensional hydrodynamic model (Delft3D). Satellite Earth Observations of lake water level, surface water temperature, and Chlorophyll‐a concentration are used, and spatially resolved water transparency is estimated from lake water leaving reflectance. The Delft3D model is calibrated and validated against in situ and satellite data, including Rainfall Estimates from Rain Gauge and Satellite Observations (CHIRPS), and in situ discharge data, while assimilating maps of water transparency to simulate surface thermal stratification accurately. Results show pronounced spatial and seasonal heterogeneity in transparency, thermal structure and phytoplankton dynamics across the three basins. Phytoplankton phenology varies from short, pulse‐like blooms in the most sensitive riverine upstream basin to longer, more coherent bloom seasons in downstream transitional and lacustrine basins. Bloom hotspots occur near shorelines and tributary mouths during windy and wet seasons, following basin‐scale circulation patterns and possibly nutrient inflows. Our integrated approach captures Lake Kariba's heterogeneity and identifies vulnerable areas, highlighting its importance for effective water resource management.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"17 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149090120","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":"A Semi‐Resolved LES‐DEM Framework for Turbulent Bedload Transport From Saltation to Sheet‐Flow Regimes","authors":"Yuxiang Liu,Lu Jing,Zi Wu,Xudong Fu","doi":"10.1029/2025wr043288","DOIUrl":"https://doi.org/10.1029/2025wr043288","url":null,"abstract":"Abstract Bedload transport widely occurs in natural environments and encompasses flow regimes from saltation to sheet‐flow, with markedly different fluid‐particle interaction characteristics. Understanding these mechanisms requires a numerical tool capable of capturing both the turbulence and fluid‐particle interactions, for which challenges exist due to the constraints of grid resolution on the coupling accuracy. Here, we propose a semi‐resolved LES‐DEM framework to overcome such limitations in the conventional volume‐averaged CFD‐DEM paradigm. A feedback‐controlled body‐force term is also proposed to maintain a prescribed discharge under periodic boundary conditions in turbulent open‐channel flow simulations. Three benchmarks are performed to examine the accuracy of the proposed framework, including clear‐water turbulent channel flow and bedload transport in both saltation and sheet‐flow regimes. The present method is demonstrated to avoid the conventional grid‐size limitation and thus allows the fluid field to be resolved on sufficiently fine grids while preserving accurate fluid‐particle coupling. We further explore the micromechanics and layerwise flow characteristics underlying the transition from the saltation to sheet‐flow regimes and identify the thickness of the transport layers as a function of the Shields number. This numerical framework offers a unified and reliable approach for simulating sediment transport across various flow regimes, providing a solid foundation for micromechanical investigations and the development of the continuum model.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"16 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149090123","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":"Laboratory Study of the Dynamics of a Pollutant Within a City Block During Urban Flooding","authors":"C. Fagour,S. Proust,E. Mignot","doi":"10.1029/2025wr042960","DOIUrl":"https://doi.org/10.1029/2025wr042960","url":null,"abstract":"Abstract During urban flooding, pollutants from point releases (e.g., sewer overflows) transported in street runoff can invade city blocks, exposing residents to contamination risks. The present laboratory study focuses on the intrusion of pollutants from flooded streets into a porous city block under steady flow conditions. The modeled city block is rectangular, with a variable number of openings in its sidewalls. Five pollutant release durations are considered. This study aims at assessing the impact of block porosity and release duration on pollutant dynamics within the block by measuring the spatial distribution of concentration using a colorimetry technique, and assuming a uniform distribution over the depth. For a continuous release of pollutant, the spatially‐averaged concentration reaches an equilibrium. The spatio‐temporal variability in concentration, and the filling timescales, strongly vary with the number of openings. With two openings, pollutant transport is driven by two recirculating mean flow cells and slow turbulent diffusion toward the cell cores, resulting in long filling timescales and a homogeneous equilibrium concentration. With four and six openings, the large‐scale oscillations of the multiple jets speed up the transition toward equilibrium. As multiple jets feature variable inlet concentrations and high unsteadiness levels, the variability in the spatio‐temporal distribution of concentration remains high at equilibrium. For the four short release durations, the subsequent flushing kinetics is independent of the release duration. The concentration follows a first‐order exponential decay. This data set could serve as benchmark data for evaluating the numerical models that solve the two‐dimensional depth‐averaged advection‐diffusion equations.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"3 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149090121","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":"Model–Observation Discrepancies in the Coupling of Vegetation Greening and Transpiration Under Rising Vapor Pressure Deficit","authors":"Shijie Li,Shanlei Sun,Guojie Wang,Zefeng Chen,Matteo Mura,Daniel Fiifi Tawia Hagan,Jian Peng,Charlotte Grossiord,Diego G. Miralles,Giovanni Forzieri","doi":"10.1029/2026wr043586","DOIUrl":"https://doi.org/10.1029/2026wr043586","url":null,"abstract":"Abstract Vapor pressure deficit (VPD), a key indicator of atmospheric dryness, has markedly increased across most global land areas due to progressive warming. Although site‐scale studies show that increasing VPD may enhance plant transpiration (Tran) and influence water and energy fluxes between land and atmosphere, this relationship has not been thoroughly investigated on the global scale. Here, we apply a binning approach to quantify the contribution of VPD to global Tran by ruling out the effect of soil moisture. To this aim, we integrate satellite‐based observations, reanalysis data sets, and simulations from sixteen Coupled Model Intercomparison Project Phase 6 (CMIP6) models into a coherent framework. VPD shows a broadly positive influence on Tran over most parts of the global land consistently across all data sets. Exceptions occur in tropical rainforests where reanalysis data and CMIP6 model outputs suggest a negative VPD‐Tran interplay. Attribution analysis suggests that increasing leaf area index reduces the positive effect of VPD on Tran in reanalysis data sets and CMIP6 models compared to satellite‐based observations. This discrepancy may reflect differences in the representation of the effective canopy‐level response to high atmospheric water demand, potentially involving stomatal regulation, plant hydraulics, and vegetation structure. Such differences may contribute to an underestimated transpiration response to VPD. These findings highlight the need to better represent physiological processes, hydraulic processes, and vegetation structural characteristics in process‐based models to capture vegetation responses to increasing water stress.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"137 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893529","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}
Ngoc T. Nguyen,Tien L. T. Du,Hyongki Lee,Hong‐Yi Li,Duong D. Bui,Hahn Chul Jung,Kuo‐Hsin Tseng
{"title":"A New Global Hypsometric Data Set Derived From Satellite and Geometric Methods for Reservoir Storage Estimation","authors":"Ngoc T. Nguyen,Tien L. T. Du,Hyongki Lee,Hong‐Yi Li,Duong D. Bui,Hahn Chul Jung,Kuo‐Hsin Tseng","doi":"10.1029/2026wr043399","DOIUrl":"https://doi.org/10.1029/2026wr043399","url":null,"abstract":"Abstract Reservoir hypsometric relationships are crucial in determining water storage changes and modeling hydrological processes. Previous studies have demonstrated that uncertainties in reservoir surface area observations are a primary source of error in satellite‐derived storage estimates. However, little research has examined how variability in hyposometric data sets influences storage estimation accuracy. In addition to evaluating the impacts of hypsometric data set variability on storage estimation, this study introduced a new, simple hypsometric satellite and geometry‐based (SAGE) approach. SAGE combines remote sensing and geometry‐based methods to generate a global hypsometric data set for 7,250 reservoirs worldwide using the Global Reservoir and Dam (GRanD) database, and its performance is compared with existing data sets. The SAGE‐based results were validated against in situ Elevation‐Volume (E‐V), Area‐Volume (A‐V) relationships and storage dynamics from 132 reservoirs in the United States and Vietnam. Validation results showed strong performance, with median Normalized Root Mean Square Error (NRMSE) of 9.2% for A‐V curves and 12.4% for E‐V curves, compared to higher median NRMSE values from other global data sets, exceeding 20% for E‐V curves and ranging from 12.5% to 32.3% for A‐V curves. Reservoir storage dynamics were then estimated by integrating satellite‐derived surface areas from the Global Reservoir Surface Area Data set (GRSAD) with the SAGE‐derived AEV curves. The SAGE‐based approach significantly improved storage estimates, reducing errors by over 20% compared to other global AEV products, based on in situ storage data from 109 reservoirs in the United States and Vietnam. Overall, this study improved the accuracy of hypsometric relationships and storage dynamics, producing a more robust product for global hydrological applications.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"150 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148932883","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}
Junqiang Xia,Xianziyi Zhang,Yifei Cheng,Meirong Zhou,Shanshan Deng
{"title":"Variation of Movable Bed Roughness in the Lower Yellow River Owing to Upstream Damming","authors":"Junqiang Xia,Xianziyi Zhang,Yifei Cheng,Meirong Zhou,Shanshan Deng","doi":"10.1029/2026wr043650","DOIUrl":"https://doi.org/10.1029/2026wr043650","url":null,"abstract":"Abstract Significant changes in flow‐sediment dynamics and channel evolution have occurred in the Lower Yellow River owing to upstream damming. Notably, the post‐dam stage has witnessed an unexpected increase in movable bed roughness and more frequent dune development, driven by reduced sediment load, coarsened bed material, and altered hydraulic conditions. However, existing formulas for movable bed roughness, mostly calibrated using pre‐dam or flume data, fail to capture these new trends. A new formula is developed to calculate movable bed roughness, considering the effects of flow condition and bedforms, based on a new criterion for flow regime partition. The spatiotemporal variations in bedforms and the contributions of different factors were discussed. Results indicate that: (a) Froude number and relative water depth are key factors of movable bed roughness. The formula shows high accuracy, with the determination coefficients under different flow regimes larger than 0.70. (b) Lower flow regime is more likely to develop after the reservoir operation, especially in the braided reach under low discharges. The frequency of lower flow regime (embodied with ripples and dunes) under the low discharge generally increased by 1.3 times during the post‐dam stage. But there is a lag in the peak frequency of lower flow regime between the braided and transitional reach. (c) Although a slight increase existed in the contributions of relative water depth to movable bed roughness during the post‐dam stage, the flow condition, was still a dominant factor, with the contributions of Froude number exceeding 60% during both pre‐ and post‐ dam stages.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"47 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893532","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}
Jack Tarricone,Ross T. Palomaki,Randall Bonnell,Zachary Hoppinen,Shadi Oveisgharan,Jorge Jorge Ruiz,Hans‐Peter Marshall,Elias J. Deeb,Carrie Vuyovich,Steven A. Margulis,Simon Yueh,Richard R. Forster,Ryan W. Webb,Daniel McGrath,Juha Lemmetyinen,Kelly Elder,Rashmi Shah,Xiaolan Xu
{"title":"Interferometric Synthetic Aperture Radar (InSAR) for Monitoring Seasonal Snow","authors":"Jack Tarricone,Ross T. Palomaki,Randall Bonnell,Zachary Hoppinen,Shadi Oveisgharan,Jorge Jorge Ruiz,Hans‐Peter Marshall,Elias J. Deeb,Carrie Vuyovich,Steven A. Margulis,Simon Yueh,Richard R. Forster,Ryan W. Webb,Daniel McGrath,Juha Lemmetyinen,Kelly Elder,Rashmi Shah,Xiaolan Xu","doi":"10.1029/2025wr042866","DOIUrl":"https://doi.org/10.1029/2025wr042866","url":null,"abstract":"Abstract Interferometric Synthetic Aperture Radar (InSAR) offers a potential pathway for measuring seasonal snow water equivalent (SWE) and snow depth at spatial and temporal scales needed for basin‐scale hydrology. First proposed for seasonal snow more than 25 years ago, InSAR uses repeat‐pass radar phase differences to estimate changes in SWE or depth caused by microwave propagation through snow. This review synthesizes InSAR‐based snow monitoring from early theoretical and satellite demonstrations through recent tower, airborne, and spaceborne studies. We summarize the retrieval physics, evaluate published validation results, compare performance across wavelengths and snow environments, and identify barriers to operational implementation. The literature shows that InSAR can provide high‐resolution, spatially distributed information on snow accumulation and ablation, especially under dry‐snow conditions when temporal coherence is maintained and snow phase can be separated from atmospheric, vegetation, soil‐moisture, and other non‐snow contributions. Longer wavelengths, particularly L‐band, help maintain coherence, reduce phase‐wrapping ambiguity, and support retrievals in some vegetated environments, making the NASA–ISRO Synthetic Aperture Radar (NISAR) mission a timely opportunity for basin‐scale testing. Remaining challenges include correcting ionospheric and tropospheric delays; defining stable reference phases; identifying, correcting, or flagging coherence loss and phase‐unwrapping errors; accounting for forest‐canopy interactions; collecting spatially distributed validation data; and scaling site demonstrations to regional or global products. Operational use will require algorithmic maturation, robust validation, and integration with other remote sensing and modeling approaches. If these challenges are addressed, InSAR‐capable satellites could become an important component of an integrated global snow observation suite.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"11 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148932602","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":"Development of a New Generic AI Model for Spatio‐Temporal Prediction of Soil Moisture and Soil Water Isotopes","authors":"Hyekyeng Jung,Dörthe Tetzlaff,Kristina Yordanova,Chris Soulsby","doi":"10.1029/2025wr041903","DOIUrl":"https://doi.org/10.1029/2025wr041903","url":null,"abstract":"Abstract Understanding water fluxes and mixing dynamics in the unsaturated zone is crucial for ecohydrological studies. Yet, observations of soil moisture and soil water isotopes remain limited in spatial extent and temporal resolution, restricting modeling studies on the critical zone. A data‐driven Artificial Intelligence (AI) approach was applied in a first attempt to simulate daily soil moisture and soil water isotopes (δ 2 H, δ 18 O) across soil profiles of a mixed land use catchment using parsimonious climate and vegetation predictors. A sequential model combined a Long Short‐Term Memory network for soil moisture and a Random Forest model for soil water isotope simulation, using LSTM‐predicted soil moisture as input. Training used ca. 2 years of daily soil moisture and one year of monthly soil water isotopes from different depths (0–100 cm) under seven land uses in the Demnitzer Millcreek catchment (66 km 2 ), NE Germany. The AI model captured seasonal and depth‐dependent hydrological patterns, outperforming a process‐based model previously applied in the catchment. Soil moisture simulations showed Kling‐Gupta Efficiency of 0.75–0.92 (RMSE: 1.81%–4.50%), while isotopes simulations achieved 0.80–0.88 (RMSE: 4.3–5.8‰ for δ 2 H, 0.6–0.9‰ for δ 18 O). However, the performance of AI model depended on the study period and catchment, showing overestimation in drier test periods and underestimation in wetter validation periods. Also, in this evapotranspiration‐dominated site, the model relied heavily on indirect climate predictors (e.g., relative humidity), derived from direct drivers (e.g., precipitation), reducing performance in short‐term hydrological responses. Our sequential model has potential as stand‐alone simulations or as a surrogate for process‐based models.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"369 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893524","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}
Pingping Yang,Lei Wang,Mengxue Lin,Zhongnian Ban,Zhongfa Zhou,Huilan Zhang,Rui Li
{"title":"A Study on the Applicability of the Linear Superposition Principle to Overland Flow Resistance Based on HR‐PIV Technology","authors":"Pingping Yang,Lei Wang,Mengxue Lin,Zhongnian Ban,Zhongfa Zhou,Huilan Zhang,Rui Li","doi":"10.1029/2026wr043630","DOIUrl":"https://doi.org/10.1029/2026wr043630","url":null,"abstract":"Abstract Previous studies have suggested that the linear superposition principle fails for thin‐layer overland flows, yet direct experimental evidence remains scarce. This work adopts high‐resolution particle image velocimetry (HR‐PIV) to measure the 2D flow fields of grain resistance and form resistance in thin‐layer overland flows. Experiments cover four bed roughnesses (grain resistance), three cylinder sizes (form resistance), and five flow discharges. Key results: (a) Streamwise velocity vertical profiles fit the Keulegan log law well ( R 2 > 0.88); the cross‐sectional mean flow velocity drops with larger roughness and cylinder diameter. (b) Flow resistance coefficient rises with roughness and cylinder size but falls with Reynolds number. (c) The wilcoxon test reveals that the summed increments of individual grain and form resistance are significantly lower than the measured total resistance increment ( p < 0.001), disproving linear superposition; the discrepancy enlarges as flow depth declines. A dimensionless product model ( R 2 = 0.86) is proposed and yields reliable predictions. (d) Coexisting resistances produce far larger high Reynolds stress regions and Reynolds stress than their separate superposition; the linear fitting slope of measured versus superimposed Reynolds stress increments equals only 0.701, demonstrating that linear superposition underestimates micro‐turbulence and explaining the mechanism of additional resistance. This study provides direct hydrodynamic evidence to revisit resistance superposition for overland flow and supports theoretical calculations in soil and water conservation.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"38 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893525","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}
Hongrong Zong,Huiqiang Wu,Jiazhi Sun,Wenyu Xu,Chunhui Lu
{"title":"Analytical Solutions for Optimizing Saltwater Extraction and Freshwater Lens Protection in Saline Riparian Aquifers","authors":"Hongrong Zong,Huiqiang Wu,Jiazhi Sun,Wenyu Xu,Chunhui Lu","doi":"10.1029/2026wr043972","DOIUrl":"https://doi.org/10.1029/2026wr043972","url":null,"abstract":"Abstract Saltwater extraction is a key strategy of the Salt Interception Schemes (SIS) in Australia's Murray River Basin, aimed at intercepting saline groundwater loads to the river and adjacent floodplains. Despite their widespread application, a general analytical framework is lacking to evaluate how pumping configuration and regional boundary conditions control riparian freshwater lenses, or to predict the maximum saltwater extraction rate that avoids capturing river‐derived fresh groundwater. Here we derive sharp‐interface analytical solutions that quantify pumping‐induced expansion of riparian freshwater lenses and the maximum saltwater extraction rate. The solutions cover four representative regional scenarios: a semi‐infinite flux‐controlled aquifer (S1), a finite‐width flux‐controlled aquifer (S2), a finite‐length head‐controlled aquifer (S3) and a rectangular head‐controlled aquifer (S4). The analytical solutions are validated against numerical simulations, showing good agreement in lens shape and maximum saltwater extraction rates. Sensitivity analysis indicates that regional boundary conditions primarily control the feasible pumping strategy. The finite‐length head‐controlled system (S3) consistently supports the highest saltwater extraction rate, whereas the finite‐width flux‐controlled system (S2) is the most restrictive. The rectangular scenario (S4) can perform either better or worse than the semi‐infinite scenario (S1), depending on aquifer geometry and extraction well location. These solutions provide a fast and transparent tool for designing and optimizing SIS in saline riparian aquifers.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"9 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893527","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}