Hydrological Processes最新文献

{"title":"Evaluating GRACE-Derived Total Water Storage Anomalies as an Indicator of Growing-Season Streamflow Drought Frequency in the Eastern United States","authors":"Abigail Dischner,&nbsp;Darren Ficklin,&nbsp;Grace Carlson,&nbsp;Seth Adelsperger,&nbsp;Taehee Hwang,&nbsp;Zhiying Li","doi":"10.1002/hyp.70746","DOIUrl":"https://doi.org/10.1002/hyp.70746","url":null,"abstract":"<p>Within the contiguous United States, streamflow droughts, or periods of abnormally low streamflow, are a rising concern due to impacts on both freshwater quantity and quality. Despite detrimental ecological, agricultural, and human health impacts, streamflow droughts are challenging to detect due to a lack of observations in many regions. The near global coverage provided by remotely-sensed datasets may offer an opportunity to provide increased insight into streamflow droughts in data-scarce regions. This study uses 1324 United States Geological Survey (USGS) gages throughout the eastern United States to identify the relationship between observed streamflow droughts and remotely sensed total water storage anomalies (TWSA) from the Gravity Recovery and Climate Experiment and the Follow-On GRACE missions (GRACE/GRACE-FO) within each study watershed. The variable threshold method was used to identify observed streamflow droughts at the 5th, 10th, 15th, and 20th percentiles for each day from May to September. To assess the relationship between TWSA and streamflow drought frequency, the percentages of growing season considered streamflow drought were generated and correlated with TWSA from 2002 to 2024. Most watersheds in the eastern United States have significant correlations (<i>M</i> = −0.49, SD = 0.19) between streamflow droughts and watershed-averaged TWSA. Regions with high variability in streamflow drought occurrence as well as routine streamflow droughts during the growing season, such as the southeastern United States, were found to have strong correlations. Weaker, or non-significant, correlations were found in regions where there are fewer streamflow droughts and low interannual variability such as New England. Less severe streamflow droughts (15th and 20th percentiles) have a stronger relationship to TWSA as they are better captured by the coarse temporal resolution of the GRACE/GRACE-FO observations than extreme streamflow droughts (5th and 10th percentiles). Similarly, during extreme storage drought defined using the GRACE/GRACE-FO Drought Severity Index (GRACE-DSI), streamflow droughts are more likely to be indicated. GRACE/GRACE-FO observations are useful for indicating broad, persistent streamflow drought rather than detecting short-lived or very extreme streamflow drought events.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 10","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70746","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205767","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":"Influence of Irrigation and Topography on Groundwater Recharge in the Canadian Prairies","authors":"Alexandra T. Bateman,&nbsp;Edwin E. Cey,&nbsp;Masaki Hayashi","doi":"10.1002/hyp.70725","DOIUrl":"https://doi.org/10.1002/hyp.70725","url":null,"abstract":"<p>Irrigation augments soil water input and generally increases groundwater recharge. However, the effects of irrigation on recharge can be complex, depending on topography, climate and other factors. In the Canadian prairies, where recharge is focused under closed topographic depressions, little has been known about the spatial and temporal variability of irrigation-induced recharge in the depression-rich environment. This study compared groundwater recharge in depressions and uplands under irrigated and unirrigated conditions at experimental sites in the prairies of Alberta, Canada. Chemical and isotopic compositions of sediment porewater showed that pre-irrigation recharge was almost negligible under uplands and increased substantially after irrigation started many decades ago. Depression-focused recharge was the main mode of recharge before irrigation, and recharge flux under depressions is still much higher than under uplands under the current irrigated condition. Recharge is negligible under the unirrigated upland under the current condition. Estimated recharge flux under irrigated upland was on the order of 30 mm year⁻¹, which was less than 10% of irrigation flux, and the increased recharge did not cause adverse effects such as excessively shallow water table or high soil salinity. Therefore, a modest loss of irrigation application efficiency may result in considerable benefits to local groundwater.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 10","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70725","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205768","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":"Stable but Transient—Episodic Sensitivity in a Buffered German Karst Headwater Stream","authors":"Christina M. Schubert,&nbsp;Robert van Geldern,&nbsp;Johannes A. C. Barth,&nbsp;Anna-Neva Visser","doi":"10.1002/hyp.70719","DOIUrl":"https://doi.org/10.1002/hyp.70719","url":null,"abstract":"&lt;p&gt;Karst headwaters often exhibit stable carbonate-system behaviour because carbonate buffering maintains consistent relationships among pH, alkalinity, dissolved inorganic carbon, calcite saturation and partial CO&lt;sub&gt;2&lt;/sub&gt; pressure (&lt;i&gt;p&lt;/i&gt;CO&lt;sub&gt;2&lt;/sub&gt;). However, it remains unclear whether this chemical stability translates into predictable CO&lt;sub&gt;2&lt;/sub&gt; evasion patterns (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;F&lt;/mi&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;CO&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {F}_{{mathrm{CO}}_2} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;), and how hydroclimatic shifts affect the resilience of buffered spring-fed systems. This study examines a karst headwater stream in northern Bavaria over 15 months, complemented by a 32 h diel survey during warm low-flow conditions. System sensitivity was evaluated as deviations from baseline carbonate-system behaviour and as spatial decoupling between &lt;i&gt;p&lt;/i&gt;CO&lt;sub&gt;2&lt;/sub&gt; and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;F&lt;/mi&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;CO&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {F}_{{mathrm{CO}}_2} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. Under baseline conditions, the stream showed a consistent carbonate-system evolution over the first 2000 m. Alkalinity remained stable, while &lt;i&gt;p&lt;/i&gt;CO&lt;sub&gt;2&lt;/sub&gt; declined from ~22 910 to ~3420 μatm, dissolved inorganic carbon decreased by ~0.7 mmol L&lt;sup&gt;−1&lt;/sup&gt;, and δ&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;DIC&lt;/sub&gt; became enriched by ~1.4‰. However, this hydrochemical consistency did not translate into predictable &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;F&lt;/mi&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;CO&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {F}_{{mathrm{CO}}_2} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; patterns. Although &lt;i&gt;p&lt;/i&gt;CO&lt;sub&gt;2&lt;/sub&gt; was highest at the spring, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;F&lt;/mi&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;CO&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {F}_{{mathrm{CO}}_2} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; peaked ~443 m downstr","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 10","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70719","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205706","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":"Evaluating Hydrological Process Information for Testing Models as Hypotheses Using a Virtual Reality Model","authors":"Moritz M. Heuer,&nbsp;Markus C. Casper,&nbsp;Keith J. Beven","doi":"10.1002/hyp.70731","DOIUrl":"https://doi.org/10.1002/hyp.70731","url":null,"abstract":"<p>Process-behavioural modelling aims to achieve accurate representation of hydrological processes in hydrological models. Evaluation of model performance on discharge alone cannot achieve this; more informative observables are needed. This poses the question of which types of observables might be most informative in discriminating between different potential models. As a way of testing the value of different observables to this end, a method was developed that uses a virtual reality model of a catchment. Based on this virtual reality, ‘observations’ were then simulated by perturbing the ‘real’ values. These observations were used to evaluate the outputs of 1800 simulations with alternative parameter sets, but with the same model structure. The simulated results for the hydrological variables discharge, discharge peaks, discharge components, incremental discharge, cosmic ray neutron sensing soil moisture (CRNS), and total water storage were then normalised with the uncertainties derived for each variable from the virtual reality model. This allowed the individual variables to be compared in terms of their ability to identify non-process-behavioural simulations. For the assumed uncertainties, it was shown that the discharge component separation by the tracer model discriminates between models particularly strongly, while CRNS serves as a complementary variable for evaluation. For all the models tried, however, significant relaxations of the limits of acceptability were required to accept any models as process-behavioural. This appeared to be the result primarily of the perturbations applied to the inputs which resulted in significant model residuals during certain periods. Since in this case there is no significant model structural error, this suggests that hydrological modellers should, as far as possible, assess the uncertainty in the model forcing data as part of the model evaluation process.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 10","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70731","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205708","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":"Hydrological Uncertainty Across Snow- and Rainfall-Dominated Sub-Basins of a Partially Glacierized Himalayan Catchment","authors":"Nikunj K. Mangukiya,&nbsp;Sagar Gupta,&nbsp;Rajat Mishra,&nbsp;Ashutosh Sharma,&nbsp;Sumit Sen,&nbsp;Ankit Agarwal,&nbsp;Domenico De Santis,&nbsp;Christian Massari,&nbsp;Silvia Barbetta","doi":"10.1002/hyp.70717","DOIUrl":"https://doi.org/10.1002/hyp.70717","url":null,"abstract":"<div>\u0000 \u0000 <p>Uncertainty in hydrological modelling is often addressed through parameter estimation, while uncertainties from model inputs and structure remain underexplored. This limitation is critical in mountainous catchments, where sparse monitoring and high spatial heterogeneity amplify uncertainty. This study assesses precipitation input, parameter and model structure uncertainties in the Alaknanda River Basin, a partially glacierized Himalayan catchment with snow-dominated upstream and rainfall-driven downstream sub-basins. Precipitation input and parameter uncertainties were evaluated using the SWAT+ model through Latin Hypercube Sampling and the Sequential Uncertainty Fitting algorithm, while model structure uncertainty was assessed using 47 conceptual hydrological models implemented in the MARRMoT framework. The precipitation input assessment shows that differences among precipitation datasets substantially affect simulated streamflow, particularly in areas with high precipitation variability. Parameter sensitivity analysis indicates that snow-related parameters exert strong control on simulated streamflows in the upper basin, with parameter uncertainty producing the widest prediction uncertainty band at the glacier-fed Joshimath station (<i>r</i>-factor 0.85). The model structure assessment shows substantial variation among conceptual model structures, with wider prediction bands at the downstream rainfall- and baseflow-dominated sub-basins (<i>r</i>-factor 0.63 at Rudraprayag-A). Structural analysis further indicates that snow storage, soil moisture and routing stores are important for reliable simulations, whereas additional storage components do not consistently improve performance. Overall, the three uncertainty assessments reveal distinct spatial patterns associated with the dominant hydrological processes across the basin. These findings highlight the need for process-specific calibration, data collection and model selection to improve hydrological predictions in complex mountainous catchments.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 10","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205760","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":"Variable Source Area Runoff Representation in the Water Erosion Prediction Project (WEPP) Model Using Multiple Overland Flow Elements","authors":"Abdisa S. Kebebew,&nbsp;Ames F. Fowler,&nbsp;Philip L. Moffatt,&nbsp;Julie Padowski,&nbsp;Erin S. Brooks,&nbsp;Jan Boll","doi":"10.1002/hyp.70720","DOIUrl":"https://doi.org/10.1002/hyp.70720","url":null,"abstract":"<p>Hillslopes are the fundamental hydrologic unit of a watershed, where subsurface flow and runoff processes are established and routed downslope to the channel network. Most models simplify hillslope flow processes without adequate attention to changes along the hillslopes when creating hydrographs at the watershed outlet. In this study, we evaluate how representing hillslopes with multiple overland flow elements (OFEs) in the WEPP model affects watershed-scale hydrologic processes and illustrate variable source area (VSA) runoff in a forested watershed. We automated fixed OFE configuration (i.e., a pre-assigned number of OFEs) and compared this to a novel topographic curvature-aware dynamic OFE configuration. We applied the model to data from Phelps Creek in the South Fork Tolt watershed in Washington, USA. and compared observed data from 2021 to 2024 with simulated streamflow. Our results show that increasing the number of OFEs systematically improved model performance and that the dynamic OFE configuration delivered optimal representation with the fewest OFEs. Importantly, representing hillslopes with multiple OFEs improved WEPP's ability to simulate both infiltration-excess and saturation-excess runoff processes, and revealed runoff source area dynamics along the hillslope profiles. Concave and S-shaped hillslope profiles exhibited downslope amplification in runoff activation, mainly due to convergence of upslope subsurface drainage on low-gradient toe slope areas where soils were fully saturated. Convex profiles exhibited toe slope area re-infiltration of surface run-on received from upper OFEs. Uniform hillslope profiles showed moderate downslope runoff increment, mostly due to downslope lateral flow accumulation. Long, strongly concave slopes produced the greatest runoff volume, and short, convex slopes generated the lowest runoff. Using the dynamic OFE configuration, the WEPP model can simulate watershed-scale VSA hydrological processes more realistically to help locate hydrologically sensitive areas.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 10","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70720","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205799","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":"Effects of Vegetation Morphologies on Flow Structures and Turbulent Diffusivity in Stream-Scale Experiments With Emergent Vegetation Patches","authors":"Inhwan Park,&nbsp;Un Ji,&nbsp;Chanjoo Lee,&nbsp;Hyung Suk Kim,&nbsp;Jongmin Kim","doi":"10.1002/hyp.70706","DOIUrl":"https://doi.org/10.1002/hyp.70706","url":null,"abstract":"<div>\u0000 \u0000 <p>This study aims to investigate the impact of foliated and leafless vegetation patches on flow structures and turbulent diffusivity using a stream-scale experiment. Partially vegetated flow measurements were analysed, focusing on three key aspects of vegetation morphology: (1) morphology-induced variations in the time-averaged velocity and turbulent kinetic energy; (2) effects of vegetation morphology on transverse and vertical turbulent diffusion; (3) the relative magnitude of transverse and vertical turbulent diffusivity. The presence of the vegetation patch led to a reduction in the vertical shear of the streamwise velocity downstream of the patch while increasing the transverse shear. Moreover, the vertically varying vegetation morphology in the foliated patch resulted in vertical variations in the location of the peak turbulent kinetic energy downstream, whereas the leafless patch showed a consistent position over the flow depth. The study also revealed reduced transverse and vertical turbulent diffusion within the vegetation patch, followed by an increase in the downstream, consistent with shear-layer-induced and wake turbulence. Notably, in the foliated patch, the relative magnitude of vertical turbulent diffusion to transverse turbulent diffusion was 0.69, which was higher than that in the leafless condition (0.46), primarily because of the presence of leaves. Furthermore, the scaling constant ratio (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>α</mi>\u0000 <mi>z</mi>\u0000 </msub>\u0000 <mo>/</mo>\u0000 <msub>\u0000 <mi>α</mi>\u0000 <mi>y</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {alpha}_z/{alpha}_y $$</annotation>\u0000 </semantics></math>) of the transverse and vertical turbulent diffusion was close to 1, indicating a more active vertical turbulent diffusion relative to cylindrical vegetation. The transverse and vertical scaling constants exhibited an inverse relationship with the solid volume fraction and were more sensitive to decreases relative to cylindrical-shaped vegetation. These significant findings suggest that the vegetation morphology regulates the magnitude and anisotropy of turbulent diffusion, with potential implications for the transport and residence time of solutes and suspended materials in vegetated flows.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 10","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149145891","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":"Correction to ‘An Initial Assessment of Winter Microclimatic Conditions in Response to Seismic Line Disturbance in a Forested Peatland’","authors":"","doi":"10.1002/hyp.70711","DOIUrl":"https://doi.org/10.1002/hyp.70711","url":null,"abstract":"<p>\u0000 <span>Bayatvarkeshi, M.</span>, <span>Ketcheson, S.</span>, <span>Weiland, L.</span>, &amp; <span>Strack, M.</span> <span>2024</span>. “ <span>An Initial Assessment of Winter Microclimatic Conditions in Response to Seismic Line Disturbance in a Forested Peatland</span>.” <i>Hydrological Processes</i> <span>38</span>, no. <span>7</span>: e15243. https://doi.org/10.1002/hyp.15243.\u0000 </p><p>In the 2nd paragraph of subsection 3.5 Soil Temperature within the 3. Results section, the text:</p><p>‘At the Tamarack site, Ts on the line is above 0^oC throughout the entire measurement period. The Ts trends with depth illustrate that the pattern of Ts has reversed on December 27th. Before that time, Ts in the deeper soil layer (i.e., 25 cm) is higher than in the shallow layer. However, at the end of December, the Ts at 5 cm is greater than the Ts at 25 cm. Under both circumstances, on the line has not experienced freezing temperature during the cold months. Contrary to the seismic line, the Ts at the depth of 5 cm at the undisturbed location is below 0^oC from November 7th to April 8th. The Ts in the deeper layer is above freezing during the full measurement period’. was incorrect due to an issue with the temperature sensor. The sensor has been recalibrated and corrected. The revised text should read:</p><p>‘At the Tamarack site, Ts on the line is approximately 4^oC and 2^oC lower than off the line throughout the entire measurement period at the depth of 5 cm and 25 cm, respectively. The Ts trends with depth illustrate that the pattern of Ts is reversed between online and offline so that Ts on the line in the deeper soil layer (i.e., 25 cm) has a lower temperature than in the shallow. However, the Ts off the line at 25 cm is greater than the Ts at 5 cm. Under both circumstances, on the line has experienced a longer freezing temperature period during the cold months than off the line. The freezing period on the line occurs almost at the same time in both layers; however, the shallow layer off the line has had a longer time period below the zero compared to the deeper layer’.</p><p>Subsequently, Figure 10 was incorrect, and the correct version is provided below.</p><p>We apologise for this error.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 10","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70711","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149068312","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":"Investigating Storm Impacts on Springs in a Karst Region Using Oxygen and Hydrogen Isotopes","authors":"Yang Wang,&nbsp;Riley G. Thomason,&nbsp;Ming Ye","doi":"10.1002/hyp.70709","DOIUrl":"https://doi.org/10.1002/hyp.70709","url":null,"abstract":"<div>\u0000 \u0000 <p>Groundwater contamination is a growing concern in many regions around the world. Karst aquifers are particularly vulnerable to contamination because surface runoff can rapidly enter the subsurface through sinkholes and conduits. This study analysed time-series oxygen and hydrogen isotope data collected before and after Hurricane Idalia to assess storm impacts on two nearby springs with different discharge rates–Sally Ward Spring (~0.6 m³/s) and Wakulla Spring (~13 m³/s)–in a karst region of North Florida in the US. The δ¹⁸O and δ²H values of rainwater from Hurricane Idalia (event water hereinafter) were −15.2‰ and −108.5‰, respectively, considerably lower than those of normal rainfall in the region (δ¹⁸O = −4.1‰ ± 1.6‰ and δ²H = −20.2‰ ± 12.2‰), providing a distinct tracer for storm-derived water. Event water appeared at Sally Ward Spring within one day and again at 12–19 and ~30 days post-storm, while it took 10–12 days to appear at Wakulla Spring. These relatively short transit times are in general agreement with previous dye-tracer-based estimates, reflecting rapid flows through sinkholes and conduits. Isotopic mass balance calculations, however, reveal that event water contributed no more than ~7% and ~1% of the discharge at Sally Ward Spring and Wakulla Spring, respectively. These results demonstrate that despite the marked differences in hydrodynamics, discharge at both springs is dominated by pre-event aquifer water, even following a major storm. The data further suggest that surface water bodies (e.g., lakes and ponds) within the springshed are important groundwater sources, contributing a substantial amount (&gt; 20%) of water to base flow at both springs. These findings highlight the complex recharge dynamics of the karst aquifer system and the limited direct contribution of event water to spring discharge. This study also demonstrated that the unique isotopic signatures of tropical cyclones can serve as powerful natural tracers in regional hydrological investigations.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 10","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149068217","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":"Thermal Regime Dynamics in a Karst Watershed Influenced by Groundwater and Urbanization","authors":"Alexandra Orr,&nbsp;Jonathan Duncan,&nbsp;Lauren McPhillips,&nbsp;Elizabeth W. Boyer","doi":"10.1002/hyp.70689","DOIUrl":"https://doi.org/10.1002/hyp.70689","url":null,"abstract":"<p>Stream temperature is an important physical characteristic that influences in-stream biological and chemical processes. An understanding of both the spatial and temporal variation in stream temperature and major factors influencing that variation, such as urban development and groundwater inflow, is critical to the management of aquatic ecosystems and in predicting how thermal regimes may respond to continued development and climate change. This study analysed daily stream temperature data between 2016 and 2024, and sub-daily (5–60 min interval) data between 2020 and 2024 in a karstic, mixed land use watershed to understand key influences on the spatial and temporal variation in stream temperature. Air–stream temperature relationships were utilised to determine the influence of factors such as groundwater inputs or overland flow. Deep groundwater sources were evident in many streams resulting in dampened diel and seasonal temperature fluctuations, while shallower flow paths likely drove higher stream temperature variability in others. The impact of urban development through thermal surge events was observed in sub-basins with higher levels of developed and impervious cover. Because the most urbanised sub-catchments also receive sustained groundwater inputs that stabilise baseflow temperatures, thermal surges at these sites were amplified by the contrast between cool, groundwater-buffered baseflow and heated stormwater runoff. These results can inform management decisions to mitigate the impact of climate change and future development.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"40 9","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70689","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148994195","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}