Jun Song, Chang Wang, Fan Mo, Haobin Xia, Jiaqi Yao, Xiaodong Niu, Qinshu Pang, Yongjian Li, Yuhao Wang, Zhen Han, Nan Xu
{"title":"A Novel Hierarchical Denoising Framework for ICESat-2: Reconstructing High-Accuracy Lake Level Series and Disentangling Climatic Drivers at Qinghai Lake","authors":"Jun Song, Chang Wang, Fan Mo, Haobin Xia, Jiaqi Yao, Xiaodong Niu, Qinshu Pang, Yongjian Li, Yuhao Wang, Zhen Han, Nan Xu","doi":"10.1002/hyp.70506","DOIUrl":"10.1002/hyp.70506","url":null,"abstract":"<div>\u0000 \u0000 <p>Quantifying the interactions between climate change, anthropogenic activities and surface water dynamics is critical for sustainable water resource management. However, bridging the data gap in remote regions remains challenging due to the coarse resolution and signal noise inherent in satellite altimetry. Addressing the specific limitation where conventional DBSCAN clustering fails to distinguish near-surface noise from primary signals, this study introduces a novel adaptive elevation statistical framework (termed the Ahsjeba algorithm) optimised for ICESat-2 photon data. Instead of relying on a single-step process, we developed a hierarchical denoising strategy that integrates coarse filtering with fine-scale statistical refinement to accurately extract water-level photons. This approach enabled the reconstruction of a dense, high-precision time series for Qinghai Lake from 2018 to 2024. Validation against in situ data confirms that this refined framework significantly suppresses noise, elevating the correlation coefficient from 0.88 to 0.99 and reducing the RMSE from 0.12 to 0.02 m, thereby overcoming the precision barriers of traditional methods. Crucially, utilising this high-quality dataset, we employed a random forest model to disentangle the complex driving factors of lake level fluctuations. The results effectively quantified the contributions of key environmental variables, providing a robust scientific basis for understanding regional hydrological responses to environmental changes. This study offers a transferable solution for precise monitoring in data-scarce, high-altitude regions.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147708068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Global Water Stress Assessment Using a Coupled Hydrological-Socioeconomic Modeling Framework","authors":"Tetsuya Fukuda, Yuichi Muto, Roman Olson, Tomoko Nitta, Takao Yoshikane, Hiroaki Kawata, Kei Yoshimura","doi":"10.1002/hyp.70520","DOIUrl":"10.1002/hyp.70520","url":null,"abstract":"<p>Water is essential for human activities, yet most global water stress assessments treat water supply and demand separately, limiting representation of dynamic environment–society interactions. Water is essential for human activities; we developed a coupled IAM-LSM framework linking the global change analysis model (GCAM) and the Integrated Land Simulator (ILS) through land-use change. We conducted simulations under the SSP1-2.6 scenario for 2020–2100. We evaluated the impact of coupling by comparing simulated monthly river discharge climatology from ILS with observations from the Global Runoff Data Centre (GRDC). The coupled system reduced discharge biases and significantly improved the representation of river flow seasonality (global mean correlation increased from 0.30 to 0.31; <i>p</i> = 0.017), demonstrating a statistically significant though modest improvement in hydrological performance. Using a flexible method to quantify inter-sub-basin water transfers, we assessed water stress and population exposure at the geopolitical sub-basin scale defined by basins and political boundaries at both annual and seasonal scales. While annual and seasonal estimates of spatial distribution and population exposure broadly agreed with previous global studies, additional water-stress hotspots were identified in regions such as South Africa, Argentina, and southeastern Brazil. Our seasonal-scale assessment further revealed water stress and population exposure that are obscured by annual aggregation, reaffirming the importance of seasonal-scale water stress evaluation. Annual exposure to severe water stress reached 2.15 billion people in 2020, whereas seasonal assessment indicated that up to 67% of the global population experienced severe stress in at least one season. Moreover, despite a simplified representation, our estimation of non-surface water use showed strong agreement in global magnitude and spatial patterns with AQUASTAT data (<i>R</i><sup>2</sup> = 0.91), indicating that aggregate groundwater and non-conventional water dependence can be approximated from surface water deficits without explicitly modeling individual components. Overall, the coupled IAM–LSM framework provides an internally consistent and scalable basis for assessing global water stress under interacting climatic and socioeconomic changes.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70520","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147708170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stewart B. Rood, Matthew J. Bogard, Lawrence B. Flanagan
{"title":"Challenged by a Climate Oscillation: Hydrology and Management of a Terminal Lake and Wetland Through the 20th Century","authors":"Stewart B. Rood, Matthew J. Bogard, Lawrence B. Flanagan","doi":"10.1002/hyp.70514","DOIUrl":"10.1002/hyp.70514","url":null,"abstract":"<p>About one-quarter of global lands include closed watersheds that drain to terminal, endorheic or saline lakes, where evaporation provides the outflow. In southwestern Alberta, Canada, the terminal Frank Lake and associated wetlands support prolific waterfowl and other wildlife. Like other prairie potholes in the North American Great Plains, Frank Lake displayed extensive variation through the 20th Century. It rose and expanded through wet intervals in the early 1900s, and again around 1950, which prompted the excavation of drainage canals to reduce flooding of adjacent agricultural lands. The lake dried up with the 1930s drought, and again in the 1980s, prompting augmentation with municipal and agro-industrial wastewater. This stabilised the lake level, but outflows in wet years contribute downstream contamination from the effluents. To characterise the system hydrology, we derived Frank Lake levels from historical reports, lake level monitoring, aerial photographs and observations. Lake levels were correlated with local temperature, precipitation and the integrative standardised precipitation evapotranspiration index (SPEI), including multiple-year influences. The strongest correspondence was with the Pacific Decadal Oscillation (PDO) and a stepwise regression model with the 3-year PDO and 2-year SPEI accounted for 72% of the 2.5 m variation in the Frank Lake levels through the 20th century. The lake also rose in years with cold springtime weather when rain and snowmelt contributed surface runoff rather than infiltration due to the frozen ground. The management of this system was challenged by the alternating wet and dry cycles, which prompted the opposing interventions of drainage versus augmentation. Similar interventions have been implemented at other terminal lakes in western North America and elsewhere and their management should similarly recognise the natural variation that accompanies climate oscillation. Finally, with hydroclimatic responsivity, terminal lakes can provide sentinels to analyse cumulative hydrological consequences from human activities combined with climatic variation and change.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70514","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147707964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sebastian Moran, Sarah Leray, Carlos A. Bonilla, Cristina Contreras
{"title":"Development and Evaluation of a Novel Soil Water Balance Approach for Mountain Catchments","authors":"Sebastian Moran, Sarah Leray, Carlos A. Bonilla, Cristina Contreras","doi":"10.1002/hyp.70503","DOIUrl":"10.1002/hyp.70503","url":null,"abstract":"<div>\u0000 \u0000 <p>Mountains are pivotal in the hydrological cycle and affect at least half the global population. However, quantifying the mountain hydrological cycle presents significant challenges owing to its inherent complexity and remoteness. Traditional soil water balance (SWB) methods, which assume sequential and hierarchical processes, fail to adequately capture the crucial contributions of vegetation and subsurface dynamics. A novel SWB method that combines a mass balance model and fully distributed water flow and storage simulation in unsaturated soil is used to address these limitations. By leveraging the concept of hillslope water sustenance, this innovative approach significantly enhances the assessment of water partitioning. It models the interactions between surface and near-surface processes with greater accuracy. This new approach was evaluated in an Andean mountain catchment, where the impact of soil, vegetation and slope on the hydrological balance components was determined for 48 representative hillslopes. The disparities between the proposed method and conventional SWB approaches are significant, particularly in scenarios where available water allows competition among different hydrologic processes. The proposed approach results in higher soil water storage, approximately 5% higher annual recharge, and, more importantly, explicitly accounts for the interflow. Recharge and interflow can constitute as much as 25% and 11% of the annual precipitation, respectively, and the water deficit can exceed 46% of the reference evapotranspiration. Following the proposed replicable workflow, it is feasible to implement a non-sequential SWB approach and better assess the competition between vegetation water use and water flow and storage on mountain hillslopes.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147707979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Great Catchment Hysteresis Challenge","authors":"Keith J. Beven, David Mindham, Nick A. Chappell","doi":"10.1002/hyp.70438","DOIUrl":"10.1002/hyp.70438","url":null,"abstract":"<p>This paper makes the argument for treating the response of small catchments as an exercise in the identification of hysteretic functions as a way of overcoming the impossibility of knowing all the small-scale detail of time variable and spatial heterogeneous catchment processes. An initial form of analysis is proposed based on the Data-Based Mechanistic (DBM) transfer function methodology to define functions for classes of events based on rainfall input volumes and antecedent flow as an index of catchment wetness. From the resulting transfer functions, event-scale storage-discharge plots can be derived if within-event evapotranspiration is neglected as small relative to event inputs. The great hysteresis challenge is to find a way of identifying a more continuous mechanistic function that allows for the change in input–output gains and transfer function state variables directly from the observed data without invoking a particular conceptual storage model structure (or structures) or a difficult-to-interpret machine-learning framework.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70438","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147707989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marcio Augusto Reolon Schmidt, Carlos Eugênio Pereira, Alan Petrônio Pinheiro
{"title":"Analysis of Rainfall Run-Off Processes in Tropical Cities Under Climate Change and Urbanisation Patterns","authors":"Marcio Augusto Reolon Schmidt, Carlos Eugênio Pereira, Alan Petrônio Pinheiro","doi":"10.1002/hyp.70510","DOIUrl":"10.1002/hyp.70510","url":null,"abstract":"<div>\u0000 \u0000 <p>Flood warning systems are essential tools for reducing risks in extreme hydrological events and, when integrated with effective response actions, contribute to mitigating material damage. However, simulations are conducted with static data, disregarding the temporal dynamics of changes in land use and land cover (LULC) and precipitation and surface run-off projections. In this study, we quantify the influence of precipitation duration and intensity and soil sealing on surface run-off and flooded area in an urban watershed in the Brazilian Cerrado. To this end, we propose a hybrid structure that integrates precipitation forecasting (LSTM with attention mechanism and Monte Carlo dropout), land use change modelling (CA-Markov with U-net) and hydrological-hydraulic simulation (HEC_HMS and HEC-RAS). The results show that soil sealing has a more significant influence on simulated peak flows than projected variations in precipitation for the period from 2025 to 2040. The simulations indicate that, regardless of changes in projected precipitation intensities, the critical duration remained equal to or less than 2 h, with the connectivity of impervious areas being the dominant factor. For 2-h events, maximum flows increased by 3.72% with current CN values and up to 8.78% in the upper scenario (CN + 11%). For 6-h events, the increase reached 16.7% in the most urbanised scenarios. These results indicate a transition from the dominant process of precipitation intensity to surface connectivity in short-duration events, with direct implications for design standards based on IDF curves. The study supports a reorientation of urban planning towards the disconnection of impervious surfaces and the control of peak flow generation.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147707978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amila Ljutic, Genevieve Ali, Laura Van Eerd, Merrin Macrae, Claudia Wagner-Riddle
{"title":"Comparing Seasonal Soil Water Storage and Flow Processes Under Different Soil Conditions","authors":"Amila Ljutic, Genevieve Ali, Laura Van Eerd, Merrin Macrae, Claudia Wagner-Riddle","doi":"10.1002/hyp.70508","DOIUrl":"10.1002/hyp.70508","url":null,"abstract":"<p>Soil moisture dynamics are known to vary greatly in space and time, especially given soil–plant-water and human interactions in agricultural environments. Knowledge gaps remain surrounding how soil moisture processes change under different soil conditions and land management practices. In this study, soil moisture storage and flow were examined over seasonal timescales in 2021 and 2022 in Southern Ontario, Canada under three soil agricultural management treatments—control (no-till), cover cropped and compacted soil. To compare soil moisture patterns, experimental plots under each treatment (three replicates) were characterized based on vertical soil moisture distributions in the root zone (0–60 cm). Monotonic versus non-monotonic soil moisture profiles were taken as an indication of different matrix and lateral flow pathways when field capacity was exceeded. Results showed that despite soil water storage trends being similar inter-treatment (i.e., similar ‘average’ changes), lower water storage capacity was measured on compacted plots. Soil moisture pattern analysis revealed 95% of the study period was characterized by non-monotonic soil moisture profiles. When monotonic patterns were identified, the control and cover crop treatments were more often associated with soil moisture that increased monotonically with depth (4% of time), attributed to better water infiltration and storage, whereas the opposite was observed for the compacted treatment. Although no dominant flow pathway could be identified for 75% of timesteps, flow pathways were more active in the spring and fall seasons, as expected, with high spatial variability of inferred instances of matrix and lateral preferential flow. Both years considered, the control and cover crop treatments each had four times more observations of capillary rise compared to the compacted treatment. The analysis of vertical soil moisture patterns therefore revealed process insights that may otherwise be overlooked when solely focusing on total soil water storage or water budget analyses.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70508","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147707975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Uncertainty Analysis of Internal Hydrological Processes in Two Agricultural Catchments in Ireland via Stochastic Calibration of SWAT+","authors":"Rodhraí Crowley, Joe Harrington","doi":"10.1002/hyp.70509","DOIUrl":"10.1002/hyp.70509","url":null,"abstract":"<p>Hydrological models are a valuable tool for providing insights into hydrological processes, particularly at different scales for which observations are not available. Calibration and uncertainty analysis of hydrological models typically focus on streamflow at the catchment outlet. However, extension of uncertainty analysis to internal model surface and subsurface hydrological processes remains less commonly practiced. The primary objective of this paper is to propagate parameter uncertainty from stochastic model calibration for river discharge simulation to quantify, analyse and compare the modelled uncertainty of hydrological fluxes via different pathways and provide more robust insights into hydrological processes. This paper focuses on two agricultural catchments in Ireland representing different scales: the River Owenabue (143 km<sup>2</sup>) and River Bandon (598 km<sup>2</sup>) catchments. A sensitivity analysis is conducted to identify important SWAT+ parameters for hydrologic simulation. To identify behavioural parameter sets for uncertainty analysis of hydrological processes, stochastic calibration using the SUFI-2 procedure in R-SWAT and evaluation of SWAT+ model performance for daily river discharge simulation are carried out. Overall, the SWAT+ model achieved satisfactory performance for prediction of daily mean river discharge in the study catchments. Uncertainty analysis of hydrological fluxes identified lateral flow as an important hydrological pathway in the study catchments, particularly in the Bandon Catchment, while agricultural tile drainage was identified as an important hydrological pathway in the Owenabue Catchment. This paper demonstrates how quantification and comparison of lower and upper bound hydrological pathway contributions provide a more comprehensive understanding of specific hydrological processes driving streamflow generation in river catchments as well as the degree of uncertainty associated with individual processes across multiple behavioural parameter sets for streamflow simulation. The approach is transferable to other hydrological models, optimisation methods and catchments in different hydroclimatic regions.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70509","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147708053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lanhui Zhang, Yanzhao Xu, Wenli Zhao, Jiewen Gou, Qi An, Yong Wang, Chansheng He
{"title":"Characterising Rainfall-Induced Soil Water Dynamics in Soil Profiles and Quantifying the Influencing Factors Over Mainland China","authors":"Lanhui Zhang, Yanzhao Xu, Wenli Zhao, Jiewen Gou, Qi An, Yong Wang, Chansheng He","doi":"10.1002/hyp.70496","DOIUrl":"10.1002/hyp.70496","url":null,"abstract":"<div>\u0000 \u0000 <p>Understanding rainfall-induced soil water dynamics (rainfall-induced SWD) is crucial for improving Earth System Models (ESMs), which have been limited in large-scale analyses. Using hourly data from 594 in situ stations, this study characterises the profile distribution patterns of rainfall-induced SWD, examines the environmental impacts and their scale effects and analyses the occurrence and controlling factors of preferential flow (PF). In the soil profile, three distinct patterns of soil water response to rainfall events were identified: a predominant shallow-decline pattern, a uniform pattern in barren land and a multi-phase pattern in areas with shallow groundwater, influenced by interactions between soil water and groundwater. The influence of rainfall and clay on soil water response amplitude decreases, while antecedent soil water content (SWC) and soil organic carbon (SOC) have increasing effects as the spatial scale decreases. Notably, these changes manifest as significant, stepwise shifts at critical scales, which should be considered in future investigations. The normalised difference vegetation index (NDVI) affects the maximum rate of the soil-wetting curve (Smax) in a bimodal fashion, with stronger impacts observed at regional scales and below 90 × 90 km<sup>2</sup>. Two distinct PF frequency distribution patterns emerge across soil layers: a consistent decrease with depth in PF frequency in the Changjiang river plain (CJ) region, corresponding with decreasing root density and microporosity. The predominant pattern is a mid-depth increase, caused by uneven grass root distribution, along with contributions from gravel content, cracks and soil fauna in deeper soils. Soil texture exhibits complex, nonlinear effects on PF frequency, varying with antecedent SWC in areas dominated by fine texture. Bulk density has a threshold effect: it negatively impacts PF frequency below 1.33 g/cm<sup>3</sup> and positively impacts it above 1.41 g/cm<sup>3</sup> in mainland China. Our results reveal novel profile patterns of rainfall-induced SWD and PF, providing fresh insights into the soil wetting process. This understanding is beneficial for effective model parameterisation and validation, ultimately enhancing the simulation of soil water dynamics in ESMs.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147708054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}