Water Resources Research最新文献

{"title":"How Hydrological Structural Connectivity Controls Red Soil Erosion During Multiple‐Intermittent Rainfalls","authors":"Yichen Yin,Taoxi Li,Jiale Ye,Yichun Ma,He Pei,Peiyao Xiao,Haiqun Yuan,Qian Zeng,Gang Sun,Ruyi Zheng,Yaojun Liu","doi":"10.1029/2026wr043839","DOIUrl":"https://doi.org/10.1029/2026wr043839","url":null,"abstract":"Abstract Hydrological structural connectivity is key to regulating hillslope erosion, but its formation and interactions with runoff‐sediment dynamics during intermittent rainfall remain unclear. Through simulated intermittent rainfall (three consecutive rainfall events with a 1‐day interval between each, intensities: 30, 60, 90 mm hr −1 ) combined with overland‐flow hydraulics measurements and high‐resolution UAV photogrammetry, this study reveals how hydrological structural connectivity dynamically controls erosion. Runoff‐sediment responses showed strong intensity dependence. At 30 mm hr −1 the runoff coefficient rose continuously, whereas under higher intensities it increased and then stabilized. Soil loss rates rose steadily at low intensity, followed a “rise‐then‐fall” pattern at medium intensity, and declined at high intensity. Connectivity strengthened with rainfall progression, but its growth rate declined as intensity increased. The key structural connectivity index |RF| rose with intensity (36.71, 39.36, 41.52 under 30, 60, 90 mm hr −1 , respectively; ×10 −6 ), while its growth rate decreases significantly (18.58%, 9.96%, 1.02%), showing earlier stabilization under high intensity. |RF| exhibits significant positive correlations with surface runoff, hydrodynamic parameters, and key rill morphological parameters, indicating that connectivity influences erosion processes by regulating flow pathways and convergence efficiency. Under low rainfall intensity, erosion promotes connectivity development, whereas under high rainfall intensity, an early‐established highly connected network constrains further erosion. As rainfall intensity increased, the erosion system shifts gradually from an “erosion‐driven connectivity development” regime to a “connectivity‐controlled erosion regulation” regime. This study reveals the nonlinear responses of hillslope erosion from a connectivity perspective, offering a theoretical basis for mechanism understanding and targeted conservation strategies.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"26 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209437","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":"Deep Learning‐Based Fusion of Hydrodynamic Model and Remote Sensing Observation for Mapping the Inundation Dynamics in Large Wetlands Under Changing Environment","authors":"Siyang Yao,Jutao Liu,Ligang Xu,Ying Le,Dong Liao,Jiang Wu,Siyu Wan","doi":"10.1029/2025wr040618","DOIUrl":"https://doi.org/10.1029/2025wr040618","url":null,"abstract":"Abstract Wetlands play a crucial role in maintaining the global ecosystem balance, and determining the inundation dynamics is of great significance for understanding wetland ecosystems. Hydrodynamic models are effective tools for mapping the inundation dynamics; however, they are affected by uncertainties arising from environmental changes, including anthropogenic pressures and land cover modifications, especially in large wetlands. To overcome hydrodynamic model limitations, this study integrated a hydrodynamic module, a remote sensing module, and a deep learning fusion module to develop an efficient approach for mapping the inundation dynamics. This approach was applied in the Poyang Lake Wetland in China, a vital conservation wetland in the Ramsar Convention. The effectiveness of this approach was verified by comparing the simulated inundation dynamics of the hydrodynamic model during the dry season. We found that the performance of the hydrodynamic model was relatively poor. In particular, the performance in the sub‐lake area was significantly inferior than the other zone, with an overall accuracy (OA, dimensionless, ranging from 0 to 1) of only 0.63–0.66. The proposed approach in this study exhibited better performance, especially in the sub‐lake area, with an OA increasing to 0.82–0.92. Furthermore, the hydrodynamic model tended to overestimate the inundation time, with the median overestimated time reaching 42–50 days. Our study provides a transferable framework that can improve the accuracy of wetland hydrological monitoring under changing environment, contribute to maintaining the ecological integrity and stability.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"14 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149210463","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":"Flood Types Reveal Non‐Stationarity in Flood Peaks Masked by Annual‐Maximum Series","authors":"Svenja Fischer,Gregor Laaha,Farhana Sweeta Fitriana","doi":"10.1029/2026wr044218","DOIUrl":"https://doi.org/10.1029/2026wr044218","url":null,"abstract":"Abstract Flood frequency analysis (FFA) forms the basis of many hydrological assessments and practical design calculations. Traditionally, FFA is based on the assumptions of stationary distributions and homogeneous samples. These assumptions are questionable in light of climate change and the wide variety of hydrological processes that lead to flooding. Furthermore, these assumptions can obscure important insights, including process‐specific changes. In this study, we develop a process‐aware, non‐stationary mixture model that combines type‐specific distributions with time‐varying parameters. An application to more than 600 catchments across Europe shows that the various flood types change differently over time. Heavy rainfall floods at many locations in Europe (e.g., the Alps and UK) are increasing significantly, whereas snowmelt floods are decreasing. In conventional models, these findings are obscured by the combined analysis of opposing trends, and trends are often not recognised. This causes design quantiles, for example, for a 100‐year return period, to be underestimated by about 15% on average in many regions of Europe when non‐stationary, type‐specific distributions are not used. Our results highlight the importance of incorporating process understanding into FFA to improve design‐flood estimation and our understanding of changing flood‐generating processes.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"66 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149090638","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":"How Data Uncertainty Influences Estimates of Root Zone Water Storage Capacity","authors":"Christopher J. Heckman,Lauren E. L. Lowman","doi":"10.1029/2025wr042672","DOIUrl":"https://doi.org/10.1029/2025wr042672","url":null,"abstract":"Abstract Root zone water storage capacity () sets the lower limit on the water available to plants and is critical for modeling terrestrial water and carbon fluxes. Due to subsurface heterogeneity in soils, roots, and geology, in‐situ measurements of are infeasible at regional to global scales. Instead, is often estimated using a water balance approach—calculating the difference between precipitation and evapotranspiration to approximate water deficits. This method can be applied using diverse data sets, including those from eddy covariance, satellite remote sensing, reanalysis, and land surface model outputs. However, each data product contains its own uncertainties, and the influence of data set choice on estimates has not been quantified. In this study, we assess the uncertainty in estimates across 90 FLUXNET sites in the continental United States with at least 5 years of data, comparing results from six different precipitation and evapotranspiration data sets. We find substantial variation in estimates across data sets, sites, and land cover types, with particularly high uncertainty for values exceeding 500 mm. Much of this uncertainty can be attributed to differences among evapotranspiration products rather than random errors. Our analysis shows that single data set approaches to quantifying underestimate the variability that emerges when multiple data sets are considered, especially in the Western US. These results underscore the need to account for data‐driven uncertainty when estimating subsurface water storage and provide a foundation for improving model parameterizations of ecosystem drought response and land‐atmosphere interactions.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"22 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149090635","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":"Quantitative Evaluation of Baseflow Separation Methods Using an Integrated Hydrologic Model in a Snow‐Dominated Watershed","authors":"Jihad Othman,Pin Shuai","doi":"10.1029/2025wr042147","DOIUrl":"https://doi.org/10.1029/2025wr042147","url":null,"abstract":"Abstract Baseflow constitutes over half of streamflow in mountainous headwaters of the western United States (US), making accurate quantification critical for water resource management. However, traditional baseflow separation methods are often arbitrary and ambiguous, complicating validation. Here, we developed an integrated hydrologic model coupling surface and subsurface flow to quantify baseflow in the Coal Creek watershed, a snow‐dominated catchment in Colorado, US. A model‐agnostic approach was implemented to estimate baseflow from simulated hydrologic exchange fluxes and these estimates were used as a reference to evaluate four common baseflow separation methods: the Pettyjohn and Henning (PH) graphical, United Kingdom Institute of Hydrology (UKIH) graphical, Eckhardt digital filter, and conductance mass balance (CMB) methods. Both the UKIH and Eckhardt methods performed relatively well, with modified Kling‐Gupta Efficiency values of 0.73 and 0.68 and Nash‐Sutcliffe Efficiency values of 0.59 and 0.71, respectively. However, the UKIH method underperformed during average and dry years, when stream hydrographs exhibit unimodal peaks typical of snow‐dominated catchments. The PH and CMB methods showed poor performance overall: the PH method substantially overestimated baseflow (average baseflow index (BFI) of 85%) owing to its short moving window, while the CMB method underestimated it (average BFI of 38%), potentially due to the exclusion of interflow contributions, compared to a numerically derived BFI of 58%. These findings highlight the utility of integrated hydrologic models as a reference for evaluating baseflow separation methods, particularly in snow‐dominated catchments where graphical and tracer‐based approaches may misrepresent baseflow contributions.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"19 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209166","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 Mechanistic Approach Accounting for Progressive Soil Surface Sealing in Interrill Erosion Modeling","authors":"Songbai Wu,Li Chen,Ninglian Wang,Tal Svoray,Shmuel Assouline","doi":"10.1029/2025wr042476","DOIUrl":"https://doi.org/10.1029/2025wr042476","url":null,"abstract":"Abstract Raindrop‐induced soil surface sealing alters infiltration, runoff, and sediment detachment, yet most erosion models fail to capture its dynamic impacts on interrill processes at event scales. Conceptually informed by the process‐based approach of Water Erosion Prediction Project, we develop a modeling framework that couples seal formation, two‐layer infiltration, kinematic wave overland flow, and interrill erosion. The framework integrates slope gradient and rainfall intensity into the temporal evolution of interrill erodibility, enabling explicit representation of sealing dynamics. Laboratory data of Assouline and Ben‐Hur (2006, https://doi.org/10.1016/j.catena.2006.02.005 ) covering rainfall intensities of 24–60 mm hr −1 and slopes of 5%–25%, were used for evaluation. The model reproduced observed sediment loads with normalized RMSE of 14%–20% and Nash‐Sutcliffe efficiencies of 0.70–0.89, outperforming the version in which the progressive sealing effect is omitted. Results highlight two competing sealing effects: reduced interrill erodibility suppresses detachment, while increased rainfall excess enhances transport capacity. Their relative importance depends on slope: increasing rainfall excess dominates erosion on gentle slopes, whereas interrill erodibility reduction controls erosion on steep slopes. The model also reveals dynamic regime shifts from transport‐limited to transitional or detachment‐limited during sealing. Comparisons show that neglecting seal formation can substantially underestimate sediment loads, whereas assuming instantaneous sealing overestimates erosion by 37%–71% on gentle slopes and underestimates it by 2%–7% on steep slopes. By resolving slope‐ and rainfall‐dependent sealing dynamics, the proposed model provides a physically based framework for event‐scale interrill erosion prediction, improving the reliability of rainfall‐runoff‐erosion assessments in erosion‐prone landscapes.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"687 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149090644","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‐Varying Operation Policies With GRU‐Based Parameterization for Adaptive Multi‐Objective Reservoir Operation Under Climate Change","authors":"Yiming Wei,Renchao Wang,Lu Zhuo,Zengchuan Dong","doi":"10.1029/2025wr043033","DOIUrl":"https://doi.org/10.1029/2025wr043033","url":null,"abstract":"Abstract Designing reservoir operation policies that can adapt to non‐stationary hydroclimatic conditions is a major challenge for water resources management under climate change. This study develops an adaptive dynamic operation policy (ADOP), in which Gaussian radial basis functions (RBFs) are coupled with a gated recurrent unit (GRU)‐based parameterization module that maps meteorological information to time‐varying RBF weights. Using the reservoir system in the Qingjiang River Basin, China, as a case study, ADOP is optimized using an expanded historical hydroclimatic ensemble within an evolutionary multi‐objective direct policy search (EMODPS) framework and is evaluated under both an independent historical test period and 12 GCM‐based climate scenarios. A static operation policy (SOP) and a scenario‐specific re‐optimized ideal operation policy (IOP) are used as benchmarks. Results show that ADOP outperforms SOP under both historical training and test conditions. Under future scenarios, ADOP achieves higher hypervolume than SOP in 10 of 12 scenarios, indicating the advantage of the time‐varying parameterization in out‐of‐sample conditions. Although both historically trained policies retain a performance gap relative to the re‐optimized IOP, ADOP partially mitigates this gap. The water‐level and release trajectories for representative years further demonstrate that the advantage of ADOP is associated with improved storage–release coordination. Moreover, a diagnostic comparison supports the value of the GRU‐based module, as adding meteorological inputs to a static RBF policy does not reproduce ADOP's gains. The proposed time‐varying policy provides a practical pathway for improving the adaptability of historically trained reservoir operation policies under uncertain future hydroclimatic conditions.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"11 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209440","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":"Spatiotemporal Dynamics of Active Root Zone Storage Revealed From Hybrid Machine Learning","authors":"Georgios Blougouras,Shijie Jiang,Alexander Brenning,Mirco Migliavacca,Louise Slater,Jialiang Zhou,Rohini Kumar,Lu Tian,Chao Wang,Markus Reichstein","doi":"10.1029/2025wr042803","DOIUrl":"https://doi.org/10.1029/2025wr042803","url":null,"abstract":"Abstract Water within the root zone regulates water, energy, and carbon exchanges at the land‐atmosphere interface, yet the dynamically active portion of subsurface water that ecosystems mobilize for evapotranspiration (ET) remains unclear, because it represents only part of the total subsurface storage. To address this gap, we develop a catchment‐scale, ecosystem‐oriented hybrid machine learning model that integrates a parsimonious ecohydrological structure with data‐driven flexibility to infer time‐varying active root zone storage (a S rz ) as a latent state variable. Without prescribing rooting depth or soil layers, the model learns adaptive water partitioning from multi‐source observations of ET, runoff, snow, and terrestrial water storage, enabling diagnosis of both dynamic a S rz and its realized capacity. Applied across hundreds of U.S. catchments over the period 2001–2020, the framework reveals coherent spatial and hydroclimatic patterns, with a S rz peaking in transitional regions where atmospheric demand and water supply are balanced. The realized capacity reflects how belowground water access varies with long‐term hydroclimatic and substrate constraints. We further show that defining storage as a realized quantity through system dynamics improves stability and interpretability under varying observational and structural conditions. Overall, this study demonstrates how hybrid modeling can be used to diagnose ecosystem‐accessible water storage as a latent state, providing a physically consistent and observation‐informed pathway to quantify belowground processes that remain inaccessible to direct measurement and control key land‐atmosphere interactions.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"181 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149150590","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":"Agricultural Drought Response in Temperate Climates Requires Institutional Development and Coordination to Support Adaptation","authors":"Rachel E. Schattman,Courtney Hammond Wagner,Sara Delaney,Janica Anderzén","doi":"10.1029/2025wr041667","DOIUrl":"https://doi.org/10.1029/2025wr041667","url":null,"abstract":"Abstract Droughts and dry periods represent a novel and emerging threat to agriculture in historically water rich, temperate regions, such as the Northeast United States. Water governance institutions to manage water quantity in these regions are underdeveloped in the context of current needs. In this study, we examine the state of Maine as a case study in drought institutions in a historically water‐rich region. Specifically, we review the institutional landscape for drought resilience and resistance for Maine agriculture and identify the gaps that may be hindering agricultural adaptation. Through focus groups with farmers and agricultural advisors, we find: (a) There are few quasi‐governmental organizations and programs dedicated to agricultural drought‐adaptation; rather farmers rely upon mostly federal, state, and non‐governmental regional programs and policies that are non‐drought specific in nature; and (b) there is a need for articulated and persistent coordination between federal‐state‐local organizations and programs, to ensure vertical and horizontal integration and complementarity. In the absence of drought‐specific institutions that coordinate across scales, there is the potential for ineffective drought adaptation and maladaptation in Maine and other temperate regions. This could result in wasted public and private resources, ineffective use of natural resources, and inequitable or otherwise socially undesirable outcomes. Our research adds to the growing body of evidence showing that, even in temperate and historically water‐rich regions, drought is a threat to agricultural viability. Here, we outline the need for institutional coordination around drought‐adaptation to facilitate strategic program development.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"407 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149150594","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":"Impact of Global Warming‐Induced Sea‐Surface Salt Concentration Changes on Island Groundwater System","authors":"Weijiang Yu,Yipeng Zhang","doi":"10.1029/2025wr042036","DOIUrl":"https://doi.org/10.1029/2025wr042036","url":null,"abstract":"Abstract Global warming is altering sea‐surface salt concentration (SSC) through intensified evaporation, shifted precipitation patterns, and accelerated melting of polar ice. Subsurface freshwater in oceanic islands is typically shaped like a thin lens due to limited land area and recharge, often the primary freshwater source for local communities and highly vulnerable to seawater intrusion (SWI). However, the effects of SSC changes on freshwater lens (FWL) and SWI extent in island aquifers remain unknown, and there is little knowledge on how hydraulic conductivity (HK), local aquifer recharge (RCH) and island width ( L ) affect these effects. To end this, this study employs a simplified two‐dimensional, variable‐density island groundwater simulation model to investigate how SSC affects FWL and SWI extent across seven distinct hydrogeological scenarios, using six quantitative indicators: relative changes in (a) average water table elevation (WTE), (b) maximum WTE, (c) FWL depth, (d) FWL thickness, (e) fresh groundwater volume, (f) aquifer salt mass. Simulation results demonstrate that rising SSC increases aquifer salt mass and elevates WTE while shrinking FWL (reducing its depth, thickness, and freshwater volume), as enhanced freshwater‐saltwater density contrasts drive more vertical flow pushing FWL upward. Island aquifers with higher HK, lower RCH, or smaller L show minimal changes in WTE and aquifer salt mass but are more sensitive to SSC changes in terms of FWL depth, thickness and fresh groundwater volume. Moreover, WTE and FWL characteristics show greater sensitivity to SSC declines than to SSC increases.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"63 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209436","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}