Hydrological Processes最新文献

{"title":"Hydrological Controls on Drip Water δ18O Heterogeneity: A 4-Year Monitoring Study in Remi Cave, Southern China","authors":"Shuyan Li,&nbsp;Yunxia Li,&nbsp;Wenyan Zhao,&nbsp;Zhimao Ye,&nbsp;Lin Zhao,&nbsp;Zhongwei Shen,&nbsp;Lidan Liu,&nbsp;Jiantao Cao,&nbsp;Zhiguo Rao","doi":"10.1002/hyp.70741","DOIUrl":"https://doi.org/10.1002/hyp.70741","url":null,"abstract":"<div>\u0000 \u0000 <p>Understanding how stable water isotopes are modified during percolation through the soil-epikarst-bedrock continuum is a fundamental challenge in karst hydrology, particularly in subtropical monsoon regions with heterogeneous infiltration dynamics. This study presents a four-year (December 2020–December 2024) isotopic monitoring dataset from Remi Cave (southern China), including three precipitation sites (P1–P3), two soil water depths (50 and 95 cm), six drip sites (D1–D6), and two surface karst springs (R1 and R2). Our results show that: (1) Soil water, drip water, and spring water all plot close to the Local Meteoric Water Line but with lower slopes and intercepts, indicating evaporative fractionation during infiltration, with shallower soil water (50 cm) exhibiting stronger evaporation than deeper soil water (95 cm). (2) Considerable spatial heterogeneity exists among drip sites: D1, D2 and D5 preserve seasonal precipitation signals with the mean residence time (MRT) of approximately 1 year (~345–366 days), modulated by cave ventilation and drip-rate variability. D3 and D4 show the most depleted δ¹⁸O values (−7.8‰ and −7.6‰, respectively) and negligible seasonal amplitudes, indicating that they are recharged primarily by wet-season rainfall. D6 exhibits an MRT of ~73 days and shares similar isotopic characteristics with the two karst springs (MRT ~60–76 days), demonstrating rapid hydraulic connectivity through preferential fracture flow. (3) The marked offsets in δ¹⁸O among coeval drip sites within the same cave reveal that hydrological pathways, rather than climatic inputs alone, determine the isotopic composition of cave drip waters. These findings provide a quantitative framework for assessing water transit and recharge in subtropical karst. They also imply that site-specific hydrology must be characterized before using speleothem δ¹⁸O for paleoclimate, and that ‘non-replicated’ records may encode past recharge dynamics.</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":"149205762","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":"Deep Seepage Estimation Under Forests in the North German Lowlands—A Deuterium Oxide Labeling Experiment in a Scots Pine and Douglas Fir Stand","authors":"Kolja Bosch,&nbsp;Paul Koeniger,&nbsp;Stefan Fleck,&nbsp;Susanne Stadler,&nbsp;Bernd Ahrends,&nbsp;Christoph Neukum","doi":"10.1002/hyp.70721","DOIUrl":"https://doi.org/10.1002/hyp.70721","url":null,"abstract":"<p>Climate resilient tree species are increasingly used in the process of forest conversion toward climate-change adapted stands. Data to quantify the impact of this forest conversion on deep seepage is scarce. This study aims to estimate deep seepage in a native Scots pine (<i>Pinus sylvestris</i>) stand and in a nonnative Douglas fir (<i>Pseudotsuga menziesii</i>) stand applying the peak shift method, based on the analysis of a tracer peak movement in the vadose zone. Deep seepage was estimated by determining the water volume between the lower root zone limit and the tracer peak below the root zone. Deuterium oxide (²H₂O) was used as a conservative tracer using small amounts of irrigation water (5.1 mm) to remain close to the natural water contents but high ²H₂O-concentrations (calculated δ²H mixture concentration ≈111 000‰ VSMOW) compared to the natural ²H₂O background concentrations. After applying the ²H₂O-tracer, soil samples were taken five times at each location over a period of 15 months with sampling depths up to 4.6 m, and 0.1 m sampling intervals. Soil water was extracted using cryogenic vacuum distillation, and stable water isotope ratios were measured with cavity ring-down laser spectrometry. From April 2023 to April 2024, deep seepage in the Scots pine stand was 0–23 mm/a (0%–2.8% of gross precipitation) while in the Douglas fir stand it amounted to 0–14 mm/a (0%–1.7% of gross precipitation). The experiment was combined with the analysis of throughfall, tracer mass recovery, grain size, bulk density and tree rooting depths as well as with soil probe measurements of volumetric water contents and matric potentials. The combination of the methods was essential to define error ranges of the peak shift method and to understand soil water dynamics between the tracer sampling dates.</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.70721","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205770","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":"Seasonal Variability of Water Vapour Dynamics in the Semi-Arid Region of Western India—Revelations From Isotopic Investigation at Mt. Abu, Rajasthan","authors":"Virendra Padhya,&nbsp;Harsh Oza,&nbsp;Akash Ganguly,&nbsp;Swagatika Chakra,&nbsp;R. D. Deshpande","doi":"10.1002/hyp.70727","DOIUrl":"https://doi.org/10.1002/hyp.70727","url":null,"abstract":"<div>\u0000 \u0000 <p>This study presents the first year-long continuous record of stable isotopes (δ¹⁸O, δD and d-excess) in atmospheric water vapour from semi-arid western India (except during periods of inoperable extreme weather conditions). Continuous in situ isotopic measurements of water vapour were made to monitor isotopic variations on daily to seasonal timescales and to discern the controlling factors. The observed temporal changes in isotopic composition are governed by variations in vapour sources and the contribution of recycled moisture. Seasonal mean values reflect a source-driven isotopic baseline: pre-monsoon [δ¹⁸O: −10.0‰; d-excess: −0.9‰], monsoon [δ¹⁸O: −10.6‰; d-excess: −5.3‰], post-monsoon [δ¹⁸O: −12.7‰; d-excess: −1.0‰] and winter [δ¹⁸O: −14.3‰; d-excess: +7.3‰]. Four distinct isotopic patterns, defined by coincident highs and lows in δ¹⁸O and d-excess, are linked to specific vapour sources: the northern Arabian Sea, evaporated terrestrial water bodies across the arid northwest, the wetter eastern interior of India and the Bay of Bengal. A dramatic isotopic shift at the end of April marks the seasonal transition from arid terrestrial to marine vapour dominance. Terrestrially recycled vapour dominates during non-monsoon months (64%–94%), while Arabian Sea contributions peak in June (~66%) and recede rapidly in post-monsoon. Vapour δ¹⁸O begins declining a median of ~14 h before rain onset (Wilcoxon <i>p</i> = 0.0005), demonstrating that vapour δ¹⁸O may serve as a reliable precursor to imminent rainfall. Atmospheric humidity and isotopic composition follow decoupled seasonal trajectories, confirming that vapour isotopes track moisture origin rather than amount, making them a uniquely powerful diagnostic tool for vapour dynamics in water-scarce regions.</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":"149205776","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":"Surface Water-Groundwater Interactions Revealed by Coupling a Glacier-Enhanced SWAT Model With MODFLOW in Cryosphere Watershed","authors":"Yaqin Li,&nbsp;Xuejiao Wu,&nbsp;Rao Zhu,&nbsp;Ziqiang Li,&nbsp;Anan Chen,&nbsp;Xiaoyan Guo,&nbsp;Yuzhong Yang,&nbsp;Tao Pu,&nbsp;Shiqiang Zhang,&nbsp;Ninglian Wang","doi":"10.1002/hyp.70739","DOIUrl":"https://doi.org/10.1002/hyp.70739","url":null,"abstract":"<div>\u0000 \u0000 <p>Climate warming has been altering cryospheric processes in cold regions, accelerating glacier retreat, reducing snow cover, leading to increased interannual variability in runoff and more frequent extreme hydrological events, thereby exacerbating hydrological instability. Consequently, exploring reliable approaches to investigate surface water-groundwater interactions in alpine cryospheric regions remains challenging and essential. Accordingly, we coupled the glacier-enhanced hydrological model (SWAT-GL) with the groundwater model (MODFLOW) to develop the integrated SWAT-GL-MODFLOW framework and to quantify such interactions in the cryospheric upper Shule River Basin on the northeastern Tibetan Plateau. The coupled model was calibrated and validated using observed streamflow and separated baseflow, demonstrating its capability to simulate basin-scale runoff dynamics and groundwater processes. For runoff, SWAT-GL-MODFLOW achieved Nash-Sutcliffe Efficiency values of 0.71 (calibration) and 0.65 (validation), improving by about 16.1% and 4.8% over SWAT and SWAT-MODFLOW, respectively. For baseflow, the simulated values showed good agreement with the baseflow separation values, with a FitNRMSE of 0.82. Our results reveal that: (1) the average contribution of glacier meltwater runoff to annual river discharge was 28.8%, highlighting its key role in runoff generation; (2) groundwater storage increased at an average annual rate of 4.2 mm/a, with 6.3 mm/a during the glacier melt season from June to September; (3) annual groundwater discharge to surface water accounted for 53.4% of the total exchange, and surface water leakage to groundwater accounted for 46.6%, with contributions of 17.1% from glacier meltwater, 7.3% from snow meltwater, and 22.2% from rainfall infiltration recharge during 2005–2020. This study provides a framework for evaluating surface water-groundwater interactions in cryospheric regions globally.</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":"149205658","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":"Slope Effect of Soil Detachment Capacity on Steep Colluvial Deposits in Southern China","authors":"Qiaoqiao Yang,&nbsp;Yuanyuan Zhan,&nbsp;Liting Zhang,&nbsp;Ying Meng,&nbsp;Wei Wu,&nbsp;Yue Zhang,&nbsp;Jinshi Lin,&nbsp;Yanhe Huang,&nbsp;Fangshi Jiang","doi":"10.1002/hyp.70723","DOIUrl":"https://doi.org/10.1002/hyp.70723","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 &lt;p&gt;Soil erosion is a major environmental issue affecting agricultural productivity and land conservation, and soil detachment capacity is a key parameter governing the erosion process. However, the mechanisms of soil detachment differ significantly across slope gradients, and the underlying causes remain to be further explored. In this study, scour experiments were conducted using small soil samples (0.1 m in diameter, 0.05 m in height) under eight slope gradients (9%, 18%, 27%, 36%, 47%, 58%, 70%, and 84%) and five unit discharges (0.56 × 10&lt;sup&gt;−3&lt;/sup&gt;, 1.11 × 10&lt;sup&gt;−3&lt;/sup&gt;, 1.67 × 10&lt;sup&gt;−3&lt;/sup&gt;, 2.22 × 10&lt;sup&gt;−3&lt;/sup&gt;, and 3.33 × 10&lt;sup&gt;−3&lt;/sup&gt; m&lt;sup&gt;2&lt;/sup&gt; s&lt;sup&gt;−1&lt;/sup&gt;) to simulate rill flow detachment processes on colluvial deposits. The objectives were to systematically elucidate the influence of slope gradient on soil detachment capacity and to quantify the difference in slope contribution rates between gentle to moderate slopes (9%–36%) and steep slopes (47%–84%). The results show that soil detachment capacity increases with the slope gradient according to a power function, but the rate of increase in detachment capacity decreases as the slope steepens. Additionally, the contribution of slope gradient to soil detachment capacity is lower for steep slopes (47%–84%) (27.2%) than for gentle to moderate slopes (9%–36%) (43.2%). Furthermore, the representation of soil detachment capacity using basic indicators (flow velocity), mechanical indicators (flow shear stress), and energy indicators (stream power) exhibits slope-dependent effects. The threshold slope for rill erodibility parameters (&lt;i&gt;k&lt;/i&gt;) and critical hydraulic variables (&lt;i&gt;v&lt;/i&gt;&lt;sub&gt;c&lt;/sub&gt;, &lt;i&gt;τ&lt;/i&gt;&lt;sub&gt;c&lt;/sub&gt;, &lt;i&gt;ω&lt;/i&gt;&lt;sub&gt;c&lt;/sub&gt;) derived from linear fitting was approximately 47%. Similarly, the threshold slope for the coefficients (&lt;i&gt;a&lt;/i&gt;) derived from the power-law fitting between soil detachment capacity and hydrodynamic variables was also 47%, whereas the exponents (&lt;i&gt;b&lt;/i&gt;) showed comparatively limited changes, with the stream power exponent (&lt;i&gt;b&lt;/i&gt;&lt;sub&gt;3&lt;/sub&gt;) remaining relatively stable across the tested slope range. Therefore, the slope-dependent effects on soil detachment capacity suggest that results from gentle to moderate slopes cannot be directly applied to steep slopes. The slope-dependent effects on soil detachment capacity confirm that results from gentle to moderate slopes cannot be directly applied to steep slopes. This study quantitatively reveals the variation rule that the contribution rate of slope to soil detachment decreases from 43.2% to 27.2%, clarifies the internal physical mechanism of the 47% slope as a hydrodynamic transition zone, and improves the theoretical understanding of soil detachment processes in steep colluvial deposits. It should be noted that this study is based on colluvial deposits derived from granite weathering crust in southern China (30% gravel, 2% clay), and the results are primarily appl","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":"149205777","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":"A Monsoon-Season Precipitation δ18O Isoscape for India: Insights Into Moisture Recycling and Atmospheric Transport","authors":"Debasis Kundu,&nbsp;A. A. Fousiya,&nbsp;Charan Teja Tejavath,&nbsp;Nitesh Sinha,&nbsp;Subodh K. Saha,&nbsp;Kiran Kumari,&nbsp;Md. Arzoo Ansari,&nbsp;C. Gnanaseelan,&nbsp;P. M. Mohan,&nbsp;Supriyo Chakraborty","doi":"10.1002/hyp.70707","DOIUrl":"https://doi.org/10.1002/hyp.70707","url":null,"abstract":"<div>\u0000 \u0000 <p>The spatial distribution of precipitation stable isotopes (“isoscapes”) provides important insights into atmospheric moisture transport, land–atmosphere interactions, and regional hydrological processes. In this study, we construct a monsoon-season precipitation oxygen isotope (δ¹⁸O) isoscape for India and investigate the mechanisms governing its spatial variability. Despite the limitations imposed by the sparse observational network, the reconstructed isoscape reveals a pronounced southwest-to-northeast isotopic gradient, with relatively enriched values over southwestern India and progressively depleted values toward northeastern India. While an inverse relationship between rainfall amount and δ¹⁸O is evident over central India, the large-scale spatial pattern cannot be explained solely by the classical amount effect. Instead, the observed isotopic distribution appears to be controlled by the combined influences of large-scale advection of moisture through monsoon circulation and moisture recycling. A phase-space analysis framework is used to examine the interactions between advected atmospheric moisture and evapotranspired moisture and to identify their characteristic timescales. The analysis reveals a strong spatial correspondence between precipitation isotope variability and recycled rainfall, demonstrating that terrestrial evapotranspiration exerts a first-order control on the isotopic composition of precipitation at the continental scale. This finding provides a mechanistic explanation for how moisture recycling shapes precipitation isotope variability across the Indian monsoon region. The study further shows that isotopically depleted rainfall associated with Bay of Bengal low-pressure systems is partly offset by the continuous advection of relatively enriched moisture from the Arabian Sea, contributing to the observed isotopic patterns over central India. In addition, an updated Indian Meteoric Water Line (IMWL) is derived using an expanded precipitation isotope dataset spanning mainland India and the island territories. Together, these results highlight the importance of land-atmosphere coupling and moisture recycling in controlling precipitation isotope variability and provide a new framework for interpreting isotope-based hydrological and paleoclimatic records from the Indian monsoon region.</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":"149205707","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":"Linkages Between Dissolved Organic Matter Quality and Denitrification Potential in Surface Water and Groundwater Mixing Zones","authors":"Zhang Wen,&nbsp;Kaihang Wang,&nbsp;Xue Ping,&nbsp;Yang Xian","doi":"10.1002/hyp.70740","DOIUrl":"https://doi.org/10.1002/hyp.70740","url":null,"abstract":"<div>\u0000 \u0000 <p>Nitrate contamination in surface water (SW) and groundwater (GW) represents a pervasive environmental challenge worldwide. The river-riparian-aquifer transition zone exerts a pivotal role in mediating nitrate export, primarily through promoting denitrification fueled by organic matter. In lowland riverine reaches, how compositional characteristics of organic matter regulate denitrification rates remains poorly elucidated, particularly in lowland reaches where processes are complicated by the combined effects of SW-GW mixing, and heterogeneous environmental conditions. This study conducted field sampling of water and sediment across the riparian continuum (SW, SW-GW mixing zone, and GW) along a representative lowland reach of the Han River. Denitrification potentials were quantified using the acetylene block technique, while the compositions and optical properties of organic matter were characterized via spectroscopic analyses. Partial least squares regression (PLSR; <i>R</i>² = 0.95) revealed that DOM quality dominates denitrification potential, with denitrifiers preferentially utilizing labile, microbially derived DOC components (C2), followed by terrestrial humic-like components (C4) derived from riverbank sediments. During low-flow periods, when labile protein-like DOM was less available, SW-GW mixing (river fraction of 10%–90%) was associated with enhanced utilization of sediment-derived humic-like C4 (<i>p</i> &lt; 0.05). This pattern is consistent with a priming-like substrate-switching mechanism, whereby small inputs of labile DOM and dynamic hydrological mixing stimulate the microbial use of semi-labile sediment-derived DOM. Such a mechanism helps sustain high denitrification potential in the mixing zone, highlighting the need to consider not only DOM quantity and quality, but also hydrologically mediated sediment OM processing in shallow riparian aquifers.</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":"149205771","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":"What Controls the Spatial Variation in Thermal Sensitivity in a Cascades River Basin During an Extreme Heat Year?","authors":"Savannah Milburn,&nbsp;Michael Krochta,&nbsp;Heejun Chang","doi":"10.1002/hyp.70745","DOIUrl":"https://doi.org/10.1002/hyp.70745","url":null,"abstract":"<p>Increasing stream temperatures resulting from climate change and consequent detrimental impacts on temperature-dependent aquatic species have signalled the need to better understand how different streams respond to changes in air temperature. This research generates a new assessment of thermal sensitivity in the Clackamas River Basin, Oregon, USA by analysing how underlying geology, climate, hydrology and land cover explain spatial variation in stream thermal sensitivity. Multiple linear regression analysis using spatially explicit landscape predictors across 72 sites identified upstream High Cascades geology, elevation, baseflow index, total upstream area and upstream shrubland area as the most significant and stable predictors determining thermal sensitivity. Spatial stream network and random forest models further validated and clarified spatial influences on stream temperature and each improved performance relative to multiple linear regression. Predictors derived at the total upstream area scale were most consistently associated with thermal sensitivity when compared to local reach contributing area or 100-m wide buffer area scales. Streams underlain by High Cascades geology, with higher baseflow and greater upstream area were substantially less sensitive to air-temperature changes (<i>β</i> = −0.27 to −0.61). Meanwhile, higher elevation (<i>β</i> = −0.51 to −0.59) and lower shrubland cover (<i>β</i> = 0.19 to 0.30) were associated with lower thermal sensitivity. Variation in predictors retained among models appears to reflect different indicators of shared underlying processes. Furthermore, this study confirms that these predictors are statistically robust drivers of stream thermal sensitivity via regularized regression techniques. Analysing why streams are more or less climate-resilient can inform management and restoration efforts and protect cold-water habitats.</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.70745","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205778","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":"From Source Waters to Rivers: Fe-Rich Colloids Control Carbon and Metal Partitioning in Western Siberian Hydrological Continua","authors":"Ivan V. Krickov,&nbsp;Sergey V. Loiko,&nbsp;Artem G. Lim,&nbsp;Darya M. Kuzmina,&nbsp;Georgy I. Istigechev,&nbsp;Liudmila S. Shirokova,&nbsp;Yuri S. Pupyshev,&nbsp;Oleg S. Pokrovsky","doi":"10.1002/hyp.70734","DOIUrl":"https://doi.org/10.1002/hyp.70734","url":null,"abstract":"<p>Colloids are a major, but still insufficiently resolved, transport phase linking terrestrial carbon mobilization to riverine export of metals and nutrients. Identifying where colloids form, how they transform along hydrological continua, and which solutes they preferentially carry is essential for predicting biogeochemical responses to permafrost thaw and changing groundwater connectivity. Here we investigated colloidal partitioning of dissolved organic carbon (DOC), major elements and trace metals along four hydrological continua of the Western Siberian Lowland spanning a 1500 km latitudinal transect and a broad climate and permafrost gradient. During summer baseflow, 29 surface waters and soil solutions were size-fractionated into low-molecular-weight (LMW; &lt; 3 kDa) and colloidal (3 kDa–0.45 μm) pools. Two robust patterns emerged. Major ions and Si remained largely in the &lt; 3 kDa fraction, whereas Fe, P and low-mobility hydrolyzing elements, including Al, Ti, Zr, Hf, Th, U, Pb and the REEs, were predominantly colloidal, especially in streams and rivers. The strongest reorganization of size partitioning occurred not among rivers of different size, but at the transition from source compartments (soil and fen waters) to the first flowing waters. Along the continua, DOC became progressively enriched in the LMW (&lt; 3 kDa) pool, whereas Fe and many trace metals became increasingly colloidal, indicating partial decoupling between carbon and metal transport. Watershed area exerted only a weak, element-specific influence. In contrast, pH and colloid composition were first-order controls: increasing pH enhanced the colloidal fractions of Fe, P, Y, Zr, Th, U and REEs, but increased the low-molecular-weight fractions of alkali and alkaline-earth elements and Mo. Ratio-based, correlational and PCA analyses consistently identified Fe/Al-rich organo-mineral colloids as the dominant carriers of low-solubility elements, with REEs and P showing stronger affinity for Fe-rich than for Al-rich colloids. Similar carrier-based partitioning reported from humid tropical humic systems suggests that Fe/Al-rich colloidal transport is not restricted to permafrost landscapes, but may represent a broader mechanism in organic-rich hydrological systems. In Western Siberia, the permafrost gradient provides a space-for-time framework in which future changes in colloidal partitioning are expected to reflect active-layer deepening and increasing surface–subsurface water exchange.</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.70734","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205657","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":"Application of a Budyko-LMDI Framework to Evaluate Runoff and Sediment Attribution Across Multi-Hydrological Periods in the Western Loess Plateau","authors":"Yiran Tang,&nbsp;Yibo Wang,&nbsp;Zhongyang Zhang,&nbsp;Hu Tao,&nbsp;Yingpu Liu,&nbsp;Zhanchao Hai,&nbsp;Zeyong Gao","doi":"10.1002/hyp.70732","DOIUrl":"https://doi.org/10.1002/hyp.70732","url":null,"abstract":"<div>\u0000 \u0000 <p>The runoff and sediment processes in the Loess Plateau exhibit significant seasonal variability, yet traditional attribution methods often overlook water balance non-closure and precipitation phase transitions at seasonal scales. Utilizing hydro-meteorological data (1980–2019) from the Zuli River Basin, this study establishes an integrated methodological workflow by systematically integrating snowfall partitioning, the ABCD water balance model and the Logarithmic Mean Divisia Index (LMDI) method into the Budyko hypothesis. The ABCD model estimates seasonal water storage changes for physical consistency, while the LMDI method ensures a residue-free decomposition of runoff and sediment drivers. Results show an overall decline in both runoff and sediment across four hydrological periods. Accounting for hydro-meteorological input and storage estimation uncertainties via Monte Carlo analysis, runoff decrease in the hydrological year and wet season is predominantly driven by human-induced underlying surface changes, with contributions of 134.58% [95% CI: 107.82% to 163.17%] and 165.10% [95% CI: 145.16% to 186.44%], whereas dry-season runoff increase is primarily propelled by underlying surface regulation (179.59%) and enhanced snowfall (105.66%), while being substantially counterbalanced by seasonal water storage depletion (−163.88%). For sediment dynamics, the reduction in the wet season is predominantly driven by underlying surface changes (<i>n</i>, 99.44% [95% CI: 86.89% to 112.57%]), whereas during the hydrological year, dry season and snowmelt period, the decline is primarily dominated by decreasing sediment concentration (<i>mC</i>), with contributions of 61.30% [95% CI: 59.56% to 63.16%], 113.91% [95% CI: 110.41% to 117.89%] and 92.80% [95% CI: 90.71% to 95.08%], respectively. However, during the hydrological year, the role of underlying surface changes also remains substantial (54.07% [95% CI: 42.56% to 65.70%]). This study clarifies seasonally divergent driving mechanisms, underscoring the reshaping of hydrological processes by human activities and the crucial regulatory role of snowfall and storage dynamics during dry and snowmelt periods. The work offers a multi-scale scientific basis for tailored soil and water conservation on the Loess Plateau.</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":"149205761","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}