Journal of Hydrology最新文献

{"title":"Dual-tracer analysis of stable isotopes and thermal signals to quantify groundwater residence times in karst rhythmic spring systems","authors":"Xulei Guo ,&nbsp;Mingming Luo ,&nbsp;Jingwen Li ,&nbsp;Yifan Chen ,&nbsp;Ye Kuang ,&nbsp;Cong Jiang ,&nbsp;Hong Zhou","doi":"10.1016/j.jhydrol.2025.133493","DOIUrl":"10.1016/j.jhydrol.2025.133493","url":null,"abstract":"<div><div>As a hydrogeological manifestation of siphon conduit-cavity coupling mechanisms in karst systems, the regulatory capacity of rhythmic spring structures on groundwater storage dynamics and their heterogeneous controls on residence time distributions remain insufficiently quantified. Focusing on the Chaoshuidong (CSD) karst rhythmic spring system in southern China, this study employs a dual-tracer framework integrating stable hydrogen–oxygen isotopes and thermal signatures with sinusoidal transfer functions and linear reservoir modeling. Hydrological time-series data encompassing precipitation, surface water, and groundwater phases were systematically collected to compute mean residence times (MRT) across distinct flow regimes, thereby elucidating structural controls imposed by siphon-conduit networks on aquifer response characteristics. Key findings demonstrate: (1) Methodological coherence in MRT estimates derived from three independent approaches, revealing shallow circulation pathways (29.5–60 d) deep circulation reservoirs with MRT greater than 198–213 days; (2) The observed approximately 40 day phase lag between thermal tracer peaks and stable isotope signatures demonstrates differential advective-conductive heat transfer mechanisms along hierarchically structured groundwater flow paths; (3) Through analysis of the peak temperatures during intermittent discharges at the CSD spring and the corresponding groundwater temperatures upstream of the flow path, the peak discharge during the siphon conduit-cavity controlled intermittent outflow was estimated to consist of approximately 10 % base flow and 90 % deep-circulating groundwater. Furthermore, the water residence time within the siphon conduit-cavity structure was determined to be approximately 279 days. This observation indicates that siphon cavities function as temporary storage and mixing reservoirs for groundwater, thereby prolonging flow duration. Furthermore, this finding underscores the efficacy of temperature tracing in quantifying the mixing ratios of diverse groundwater sources. This study contributes to an enhanced understanding of water cycling within complex karst basins and extends the application of environmental isotopes to groundwater research.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"661 ","pages":"Article 133493"},"PeriodicalIF":5.9,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144098696","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":"Predicting hydrological drought indices using a hybrid data-driven model incorporating hydrological, geomorphological, and human activity impacts","authors":"Pin-Chun Huang","doi":"10.1016/j.jhydrol.2025.133491","DOIUrl":"10.1016/j.jhydrol.2025.133491","url":null,"abstract":"<div><div>This study presents a hybrid data-driven model to predict hydrological drought indices by integrating geomorphological, hydrological, and human activity factors. The model is trained using streamflow data simulated by the SWAT (Soil and Water Assessment Tool) and incorporates spatial zoning via Self-Organizing Map (SOM) networks to account for spatial variability across different zones. Each zone is trained independently using a ConvLSTM (Convolutional Long Short-Term Memory) model, which captures spatial and temporal information critical to hydrological time series data. Key input factors include geomorphological features such as drainage area, stream order, land cover, and hydrological and meteorological conditions like precipitation and evapotranspiration. Human activity factors, such as groundwater abstraction and industrial water consumption, are also integrated to reflect their impact on drought conditions. The trained model outputs two key hydrological drought indices, the standardized runoff index (SRI) and drought deficit volume, which are used to assess drought severity and further employed to calculate more metrics concerning drought termination. The hybrid model enhances drought prediction accuracy by leveraging the spatial and temporal dynamics of the watershed system without the additional use of a hydrological model. With a 30-day (1-month) prediction window, the model effectively captures temporal drought patterns while maintaining a balance between accuracy and computational efficiency. Furthermore, key evaluation metrics confirm the model’s accuracy and robustness. The Mean Relative Error (MRE) is less than 0.058, indicating minimal prediction error, while the Nash-Sutcliffe Efficiency (NSE) is greater than 0.905, demonstrating strong agreement with observed values. Additionally, the Pearson Correlation Coefficient (PCC) exceeds 0.976, highlighting a near-perfect correlation between predictions and actual data. These findings confirm the model’s reliability and effectiveness in drought prediction. These improvements provide valuable insights for efficient water resource management and drought impact mitigation.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"660 ","pages":"Article 133491"},"PeriodicalIF":5.9,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071326","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":"Facilitating sensitivity analysis of hydrological models through knowledge-driven configuration and distributed online model services","authors":"Peilong Ma ,&nbsp;Min Chen ,&nbsp;Shuo Zhang ,&nbsp;Zhiyi Zhu ,&nbsp;Zhen Qian ,&nbsp;Zaiyang Ma ,&nbsp;Fengyuan Zhang ,&nbsp;Wenwen Li ,&nbsp;Songshan Yue ,&nbsp;Yongning Wen","doi":"10.1016/j.jhydrol.2025.133406","DOIUrl":"10.1016/j.jhydrol.2025.133406","url":null,"abstract":"<div><div>Hydrological models (HMs) are essential for understanding the complexities of the water cycle and runoff dynamics. Sensitivity analysis (SA), an essential component of HMs, plays a key role in identifying the parameters that have the greatest impact on model outcomes. It helps to simplify the complexity of hydrological systems and provides a comprehensive understanding of the underlying physical processes. However, the complexity of HMs and the diversity of SA methods pose significant challenges for researchers, making the SA configuration process intricate and requiring substantial computational resources. To address these challenges, we propose a comprehensive strategy that integrates knowledge-driven configuration services with distributed online model services. First, we establish a rule-based knowledge repository and a case-based knowledge repository. These repositories provide general configuration guidance and similar SA case recommendations, respectively, to support decision-making in critical SA steps. This ensures that the configuration of SA is accurate and reliable. Secondly, we encapsulate HMs as web services and leverage distributed computing resources to optimize execution efficiency. Then, we integrate the HM services with the SA modules to achieve a complete SA experiment. Based on this strategy, we finally developed a prototype system that offers a user-friendly tool for conducting SA with enhanced computational performance and streamlined workflow. The watershed-scale HM, SWAT, was used to test the effectiveness of the prototype system. The results demonstrate that this strategy enables more comprehensive analysis and improves decision-making through configuration guidance, and holds promise for enhancing the reliability and efficiency of SA in hydrological modeling.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"660 ","pages":"Article 133406"},"PeriodicalIF":5.9,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144069745","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":"Critical hydro-geomorphological characteristics related to lateral erosion–deposition difference within the multilevel bifurcation system of the Yangtze Estuary, China","authors":"Boyuan Zhu ,&nbsp;Shiyu Zhang ,&nbsp;Lingling Zhu ,&nbsp;Lingfeng Liu ,&nbsp;Wenjun Yu ,&nbsp;Jinwu Tang ,&nbsp;Yongzhou Cheng ,&nbsp;Yitian Li ,&nbsp;Alistair G.L. Borthwick","doi":"10.1016/j.jhydrol.2025.133497","DOIUrl":"10.1016/j.jhydrol.2025.133497","url":null,"abstract":"<div><div>Swings of ebb flow axes among branching channels alter the lateral hydrodynamics within bifurcating estuaries, causing the channels to undergo erosion–deposition transitions. This study examines the three-order bifurcation system of the Yangtze Estuary through integrated analysis of observed water–sediment and terrain data from 1950 to 2022 and simulations by a shallow flow model based on Delft 3D. The model is shown to perform well in hindcasting the flow behavior in the Yangtze Estuary and in identifying critical runoff discharges at which the ebb flow axis migrates between the north and south branching channels of each-order bifurcation under corresponding tidal ranges. These critical runoff discharges occur at mutation points where ebb partition ratios of the north/south branching channels increase/decrease abruptly with gradually increasing runoff. By applying linear regression to critical runoff discharges and corresponding tidal ranges at each bifurcation order, the value domain divides into two subareas corresponding to the position of the ebb flow axis in north and south branching channels. We find the multiyear average duration days of ebb-flow-axis location to be effective as an indicator of the mean and spread of erosion–deposition in the branching channels and detect the critical values at erosion–deposition transitions. Other influence factors, including peak river discharge, sediment flux, offshore dynamics, and local engineering projects, also impact on erosion–deposition in the branching channels. The ranked orders of critical runoff discharges and critical duration days among the three-order bifurcations are interpreted, and these critical indexes are linked to the water excavating force, indicating their reliability and effectiveness. Seasonal flattening of runoff discharge, controlled by large cascade reservoirs in the upper Yangtze, has greatly shortened and lengthened location duration of ebb flow axis in the north and south branching channels at each-order bifurcation, and is likely to maintain their respective deposition and erosion behaviors in the future.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"660 ","pages":"Article 133497"},"PeriodicalIF":5.9,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144084684","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":"Data-driven collaborative safety evaluation for seepage reliability of embankments considering spatial variability","authors":"Bin Xu ,&nbsp;Zichong Liu ,&nbsp;Rui Pang ,&nbsp;Yang Zhou","doi":"10.1016/j.jhydrol.2025.133490","DOIUrl":"10.1016/j.jhydrol.2025.133490","url":null,"abstract":"<div><div>Seepage safety analysis in real embankments considering hydraulic parameters’ spatial variability is crucial. However, random seepage analysis in embankments is often lack of efficiency and accuracy for evaluation of low failure incidents based on complex random fields and fine finite element models. To improve both analytical efficiency and accuracy, a data-driven collaborative safety evaluation framework that integrates the Optimized Linear Estimation Method (OLEM) with Refine Subset Simulation (RSS) has been proposed. Firstly, the random field of the uncertain parameters of the soil–water characteristic curve (SWCC) is efficiently discretized using OLEM based on the results of deterministic analysis, and a sensitivity analysis is performed accordingly. Then, considering various combinations of spatial variability degrees of hydraulic parameters, RSS is applied to the rough mesh model for random finite element analysis, while fine element cases are generated using the Response Conditioning Method (RCM) for further collaborative safety evaluation. Finally, the accuracy of the method is validated by comparing it with the Monte Carlo Simulation (MCS) based on the same 3D rough model, and the relevant seepage safety analysis is conducted. The findings reveal that the coefficient of variation (COV) and autocorrelation distance of the permeability coefficient <em>Ks</em> in the filling section significantly impact the dam’s seepage safety. Despite strong spatial variability in parameters, the probability of seepage failure remains below 10^-3. The RSS method reduces computation time to 1/10 compared to MCS at a 10^-3 failure level.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"660 ","pages":"Article 133490"},"PeriodicalIF":5.9,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089762","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":"Human flood adaptation characteristics: A comparative study of three global river deltas","authors":"Shupu Wu ,&nbsp;Yang Hu ,&nbsp;Wenzhen Zhao ,&nbsp;Lv Gong ,&nbsp;Yuanhao Song ,&nbsp;Chenghong Li ,&nbsp;Xiuzhen Li ,&nbsp;Md.Jaker Hossain ,&nbsp;Xinmeng Shan ,&nbsp;Jiayi Fang ,&nbsp;Jie Yin ,&nbsp;Weiguo Zhang ,&nbsp;Qing He","doi":"10.1016/j.jhydrol.2025.133531","DOIUrl":"10.1016/j.jhydrol.2025.133531","url":null,"abstract":"<div><div>River deltas are critical socio-economic and ecological regions but face heightened flood risks due to climate change and urbanization. Taking the Ganges-Brahmaputra-Meghna (GBM) River Delta, the Mississippi River Delta, and the Yangtze River Delta as case studies, this research aims to reveal the characteristics and formation mechanisms of human adaptation to flood risks across different deltaic regions. Through integrating hydrodynamic modeling, spatiotemporal analysis, and multi-source datasets, this study systematically investigates flood adaptation characteristics across three major deltas based on a newly developed comprehensive framework of Human-Flood Distance (HFD) and resilience. The results show that: spatially, while these three deltas exhibit varying degrees of inundation extent, each faces unique flood vulnerability challenges; temporally, the GBM River Delta exhibits stabilized population growth and HFD recovery after initial contraction, the Mississippi River Delta shows significant fluctuations in both population and HFD, while the Yangtze River Delta demonstrates continuous population growth with steady HFD increase; in terms of adaptation mechanisms, resilience assessment indicates that the Mississippi River Delta demonstrates the highest resilience, primarily driven by recovery capacity, the Yangtze River Delta shows limited but structurally supported resilience, while the GBM River Delta exhibits negative indices due to multiple constraints. These findings emphasize the importance of developing context-specific flood risk management strategies and provide feasible flood prevention solutions for policymakers, particularly in formulating adaptation strategies that comprehensively consider both flood safety and sustainable development.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"660 ","pages":"Article 133531"},"PeriodicalIF":5.9,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089763","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":"Microbial effects on flow rates and dissolved organic carbon migration through inactive supply wells: Insights into the mechanisms of biological clogging","authors":"Zhang Wen ,&nbsp;Xu Li ,&nbsp;Qi Zhu ,&nbsp;Jianlong Huang ,&nbsp;Hamza Jakada","doi":"10.1016/j.jhydrol.2025.133494","DOIUrl":"10.1016/j.jhydrol.2025.133494","url":null,"abstract":"<div><div>Inactive supply wells (ISWs) can act as preferential flow paths facilitating the transfer of dissolved nutrients, petroleum pollutants and other undesirable constituents between aquifers, which can degrade groundwater quality, through a process known as cross-contamination. Specifically, dissolved organic carbon (DOC) can migrate into deep aquifers through ISWs, influencing the migration and transformation of various contaminants. DOC also participates in biogeochemical reactions driven by microbial activity, which can foster biological clogging near ISWs, reducing flow rates and hindering the migration of contaminants. However, the role of biological clogging in altering flow rates and DOC migration through ISWs has not been exhaustively investigated. To address this gap, a novel cross-contamination model for DOC was developed, incorporating advection, radial dispersion, multispecies and multiphase reactive transport and biological clogging, with the aim of elucidating the effects of the microbial processes on flow rates and DOC migration. The finite-difference method was employed to solve the model, and discuss the impacts of biological clogging on hydraulic conductivity, flow rates, spatial concentration distribution and breakthrough curves (BTCs). Our results showed that microbial growth near ISWs results in a reduction in porosity (approximately 45 %) and hydraulic conductivity (approximately 64 %) in a confined aquifer. In addition, biological clogging decreases flow rates, while higher concentrations of dissolved oxygen (DO) exacerbate the clogging, further reducing flow rates. Finally, microbial consumption of DOC results in a reduction in its migration range. These biological effects play a crucial role in the protection of groundwater resources, and these findings provide valuable insights for the management of ISWs, especially regarding biological clogging mechanisms and the protection of deep groundwater resources.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"660 ","pages":"Article 133494"},"PeriodicalIF":5.9,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071375","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":"Unraveling the influence of paleochannels in coastal environments vulnerable to saltwater intrusion: A synergistic approach of electrical resistivity tomography and groundwater modeling","authors":"Xiao Yang ,&nbsp;Shuai Shao ,&nbsp;Chao Jia ,&nbsp;Kaifang Kong","doi":"10.1016/j.jhydrol.2025.133500","DOIUrl":"10.1016/j.jhydrol.2025.133500","url":null,"abstract":"<div><div>Paleochannels play a dual role in coastal aquifers, acting as groundwater reservoirs while also serving as preferential pathways for seawater intrusion. Understanding their influence on groundwater salinization is crucial for coastal water resource management. This study integrates geophysical, geochemical, and isotopic methods to delineate paleochannel morphology and assess its role in saltwater migration. A petrophysical conversion model was developed to transform electrical resistivity anomalies into total dissolved solids (TDS) distributions, enhancing subsurface characterization. Electrical resistivity tomography (ERT), borehole data, hydrochemical analysis, and stable isotope tracers (δ¹⁸O, δ²H) were combined to identify groundwater sources and flow dynamics. A numerical solute transport model incorporating these datasets was established to investigate the role of paleochannels in controlling groundwater salinity. Results indicate that paleochannels significantly influence groundwater salinity, with TDS concentrations following the trend: unconfined &gt; semi-confined &gt; confined aquifers. Groundwater within paleochannels is predominantly derived from precipitation, but excessive pumping accelerates seawater intrusion, whereas increased recharge mitigates its effects. The integration of geophysical anomalies with hydrochemical data effectively identifies paleochannel structures, particularly in shallow aquifers, providing a robust approach for assessing their vulnerability to seawater intrusion. The integration of geophysical anomalies with hydrochemical data effectively identifies paleochannel structures, particularly in shallow aquifers, providing a robust approach for assessing their vulnerability to seawater intrusion. This multi-source data framework offers an improved methodology for mapping paleochannel distribution and quantifying its role in coastal groundwater salinization, providing critical insights for water resource management and aquifer protection.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"660 ","pages":"Article 133500"},"PeriodicalIF":5.9,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071373","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 standard for dew measurement","authors":"D. Beysens ,&nbsp;S. Lefavrais ,&nbsp;M. Muselli ,&nbsp;P. Rébillout ,&nbsp;L. Royon","doi":"10.1016/j.jhydrol.2025.133527","DOIUrl":"10.1016/j.jhydrol.2025.133527","url":null,"abstract":"<div><div>There is a growing interest to harvest water from the air by passive means (dew). However, there is surprisingly up to now no universal reference measurement for dew. The main difficulty is obtaining well-defined radiative cooling and heat exchange with air. For this purpose we report here a numerical and experimental study of a symmetrical condensing device (disk with fairing) where radiative cooling and air flow are well characterized. The different condensing materials (polymethyl methacrylate, OPUR polyethylene-based foil, clear glass) are such that their emissivity is close to that of water. A one-year experiment (June 2023 – July 2024) was carried out in Ajaccio (Corsica, France) at the Météo France airport meteorological station. The site configuration is characterized by a steady wind blowing from the SW (day, sea breeze) and the NE (night, mountain breeze), mimicking a wind-tunnel. Dew was continuously measured by weighing, and the condensing disk temperature was mapped with an IR camera. The temperature profiles were seen to compare well with a numerical simulation of the air flow. The heat exchange coefficient was found to follow a square-root dependence on air flow velocity (wind speed plus natural convection), as expected for laminar flow. It follows from the study that the rounded disk configuration can be defined as a dew measurement standard. The corresponding device can be easily reproduced and allows quantitative comparison of dew yields to be made anywhere.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"661 ","pages":"Article 133527"},"PeriodicalIF":5.9,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144106988","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":"Physics-constrained machine learning for satellite-derived evapotranspiration in China","authors":"Chen Zhang ,&nbsp;Chang Zhou ,&nbsp;Geping Luo ,&nbsp;Su Ye ,&nbsp;Zhou Shi","doi":"10.1016/j.jhydrol.2025.133512","DOIUrl":"10.1016/j.jhydrol.2025.133512","url":null,"abstract":"<div><div>Evapotranspiration estimates for China derived from empirical and physical models exhibit limited agreement in magnitude and trends, due to the complexity of surface characteristics and climatic conditions. Advances in knowledge-guided data-driven methods allow hybrid models that integrate remote sensing-based ET algorithms with machine learning (ML) to mitigate these discrepancies effectively. We developed two hybrid models, ML_PM and ML_SEB, by coupling the Penman Monteith (PM) and surface energy balance (SEB) algorithm with three ML methods: Artificial Neural Networks (ANN), Random Forest (RF), and Light Gradient Boosting Machine (LGBM), and then simulated China’s ET from 2001 to 2022. The hybrid models ML_PM, ML_SEB, replaced empirical formulas of the critical but uncertain parameters: surface resistance (rs) and aerodynamic resistance (ra) with ML, respectively, considering energy balance and turbulent diffusion processes. Hybrid modeling enhanced the representation of physical processes while preserving high estimation accuracy. We evaluated the hybrid models using 63 eddy covariance (EC) sites across China and compared them with process-based physical models and pure ML. Results indicated that the hybrid models ML_PM and ML_SEB substantially improved the performance of the PM (NSE: 0.49) and SEB (NSE: −0.53), achieving NSE values of over 0.8 and 0.6, respectively. ML_PM, in particular, performed on par with pure ML overall and outperformed them for grassland and forest ecosystems, owing to its stronger physical foundation. Moreover, the hybrid models demonstrated greater robustness and generalization under sparse sampling and extreme events compared to pure ML. The optimal hybrid model (RF_PM) produced an annual mean ET of 580.33 ± 9.01 mm yr⁻¹ for China over 2001–2022, with a statistically insignificant increasing trend (0.52 mm yr⁻², p &gt; 0.05). Overall, hybrid modeling achieved an optimal balance between physical mechanism and estimation accuracy, offering a new perspective for ET estimation and enhancing our understanding of hydrological processes at regional and global scales under climate change.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"660 ","pages":"Article 133512"},"PeriodicalIF":5.9,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144069738","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}