Hydrological Processes最新文献

{"title":"Quantifying the Impact of Changed Soil Properties on the Sharp Increase in Slope Erosion Following a Shallow Landslide","authors":"Sha Chen,&nbsp;Songbai Wu,&nbsp;Li Chen,&nbsp;Wenzhao Guo,&nbsp;Sheng Hu,&nbsp;Haijun Qiu","doi":"10.1002/hyp.70160","DOIUrl":"https://doi.org/10.1002/hyp.70160","url":null,"abstract":"<div>\u0000 \u0000 <p>The abrupt changes of soil properties after shallow landslides were found to greatly increase the soil erosion on loess slopes in field and laboratory experiments in Loess Plateau, but which properties play the dominant role under various conditions is still unclear. To address this issue, a simplified runoff and soil erosion model was applied to quantitatively identify the contribution of four changed properties at the landslide scar on soil erosion aggravation after a shallow landslide. The slope angle, soil, and the length and location of the landslide scar were further analysed in detail to determine if the dominant roles vary with these parameters. The results show the model can accurately simulate the sediment yields before and after shallow landslides. After shallow landslides, the increasing rainfall excess rate and soil erodibility play dominant roles in soil erosion aggravation, which cause 4.95–90.75 and 3.08–17.92 times larger sediment yields, respectively, than those before shallow landslides. Moreover, the effects of increasing rainfall excess rate and soil erodibility can complement and reinforce each other in the soil erosion aggravation following a shallow landslide. A sensitivity analysis shows that the dominant factors remain unchanged, even though the impacts of changed soil properties on soil erosion aggravation can vary substantially for different slope angles and shallow landslide characteristics. In addition, using a temporally varying soil erodibility in the landslide path can account for the impact of remnant loose soil over there, and the simulation agrees much better with the observations. These results are expected to deepen our understanding of how shallow landslides aggravate the following soil erosion and formulate an optimal strategy to control the combined gravity-hydraulic erosion in the Loess Plateau.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949926","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":"Subsurface Lateral Flow in Steep Granite Slope and Its Relation to Benggang Erosion","authors":"Hao Zhang,&nbsp;Wenkai Li,&nbsp;Ziqiang Zou,&nbsp;Shengjie Li,&nbsp;Lu Qin,&nbsp;Zhengcao Tian,&nbsp;Yangbo He,&nbsp;Lirong Lin,&nbsp;Jiazhou Chen","doi":"10.1002/hyp.70157","DOIUrl":"https://doi.org/10.1002/hyp.70157","url":null,"abstract":"<div>\u0000 \u0000 <p>Rainfall-induced soil slope failures represent a widespread issue, with subsurface lateral flow (SLF) playing a pivotal role in slope hydrological processes and stability. Monitoring SLF remains challenging owing to its spatially heterogeneous distribution and complex pathways. Through continuous soil moisture monitoring on steep granite slopes from 2016 to 2022, this study estimated SLF dynamics using the Soil Moisture Mass Balance (SWMB) method and SEEP/W numerical modelling. The results demonstrated that SLF frequency exhibited a positive correlation with rainfall frequency, with the highest annual mean SLF (1811.0 mm) recorded at the downslope position near the Benggang wall, followed by the midslope (1605.6 mm) and upslope (1211.3 mm). Saturated SLF developed when antecedent soil water content reached the field capacity on the upslope (0.38 cm³/cm³) and midslope (0.36 cm³/cm³) and approached the field capacity on the downslope (0.31 cm³/cm³), with the precipitation exceeding 20 mm. Benggang wall collapses were observed during heavy rainfall events, with cumulative SLF at the downslope position before the collapse of the Benggang wall reaching more than 238.4 mm. The SWMB method failed to estimate the SLF during long-duration or heavy rainfall events. Compared to the SEEP/W model, the SWMB method underestimated the SLF, exhibiting an average discrepancy of 527.1 mm during collapse events. The findings confirm that SLF is an important reason for the instability of the steep slope, and the saturated SLF can indicate the Benggang wall collapse.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143939207","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":"Spatial and Temporal Variability of River Water Quality","authors":"Linus S. Schauer,&nbsp;James W. Jawitz,&nbsp;Matthew J. Cohen,&nbsp;Andreas Musolff","doi":"10.1002/hyp.70154","DOIUrl":"https://doi.org/10.1002/hyp.70154","url":null,"abstract":"<p>The deterioration of stream water quality threatens ecosystems and human water security worldwide. Effective risk assessment and mitigation requires spatial and temporal data from water quality monitoring networks (WQMNs). However, it remains challenging to quantify how well current WQMNs capture the spatiotemporal variability of stream water quality, making their evaluation and optimisation an important task for water management. Here, we investigate the spatial and temporal variability of concentrations of three constituents, representing different input pathways: anthropogenic (NO₃⁻), geogenic (Ca²⁺) and biogenic (total organic carbon, TOC) at 1215 stations in three major river basins in Germany. We present a typology to classify each constituent on the basis of magnitude, range and dominance of spatial versus temporal variability. We found that mean measures of spatial variability dominated over those for temporal variability for NO₃⁻ and Ca²⁺, while for TOC they were approximately equal. The observed spatiotemporal patterns were robustly explained by a combination of local landscape composition and network-scale landscape heterogeneity, as well as the degree of spatial auto-correlation of water quality. Our analysis suggests that river network position systematically influences the inference of spatial variability more than temporal variability. By employing a space–time variance framework, this study provides a step towards optimising WQMNs to create water quality data sets that are balanced in time and space, ultimately improving the efficiency of resource allocation and maximising the value of the information obtained.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70154","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930530","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":"Wave Motion and Sediment Resuspension Influenced by Aquatic Vegetation With Varying Morphologies","authors":"Yinghao Zhang,&nbsp;Xiao Zhang,&nbsp;Wenjuan Yuan,&nbsp;Zhanfei Zhang,&nbsp;Xijun Lai","doi":"10.1002/hyp.70158","DOIUrl":"https://doi.org/10.1002/hyp.70158","url":null,"abstract":"<div>\u0000 \u0000 <p>Wind-driven sediment resuspension is a common phenomenon and impacts water quality and ecological balance in shallow lake systems. Aquatic vegetation (AV) alters the local hydrodynamics and thus influences the sediment resuspension processes, with its morphology as one of the most important factors. To understand the effect of AV on wave and sediment motion, field experiments were conducted for a year across a complete plant growth cycle in Dongping Lake, China. The vegetation morphology, water velocity, suspended sediment concentration, and wind direction/velocity were monitored within a patch of submerged flexible vegetation (i.e., <i>Potamogeton crispus</i>). Results showed that the existence of AV not only dampened the significant wave height (<i>H</i>_<i>s</i>) within the patch, but also attenuated the in-canopy wave orbital velocity (<i>U</i>_{<i>w_horiz</i>}) compared with the water surface, which indicated a dual reduction for near-bed wave velocity compared with bare-bed conditions. Variations of wave height and velocity reduction were related to vegetation morphological parameters. With vegetation experiencing its flourishing to senescent stages, the decrease of plant roughness density (i.e., from 3.89 to 1.81) weakened the wave velocity attenuation (i.e., from 12.7% to 5.4%). In the present study, the near-bed wave velocity in the centre of the vegetation patch was reduced by 40%–55%, even for the cases with vegetation in the senescent stage. The reduced near-bed wave velocity increased the critical velocity for sediment incipient motion from 3.0 cm/s for bare-bed conditions to 5.0 cm/s in vegetated cases. Besides, relationships between near-bed sediment concentration and hydrodynamics demonstrated wave dominance in resuspension initiation, transitioning to combined wave-current control during sustained suspension events. This study highlighted the effect of vegetation morphology induced by phenological evolution on wave-sediment motion, and its results have great significance for water pollution control and ecological restoration in shallow lakes.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930529","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":"Variability in Hydrologic Response to Wildfire Between Snow Zones in Forested Headwaters","authors":"Q. M. Miller,&nbsp;D. M. Barnard,&nbsp;M. G. Sears,&nbsp;J. C. Hammond,&nbsp;S. K. Kampf","doi":"10.1002/hyp.70151","DOIUrl":"https://doi.org/10.1002/hyp.70151","url":null,"abstract":"<p>Rising temperatures and shifting fire regimes in the western United States are pushing fires upslope into areas of deep winter snowpack, where we have little knowledge of the likely hydrologic impacts of wildfire. We quantified differences in the timing and magnitude of stormflow responses to summer rainstorms among six catchments of varying levels of burn severity and seasonal snowpack cover for years 1–3 after the 2020 Cameron Peak fire. Our objectives were to (1) examine whether responsiveness, magnitude, and timing of stormflow responses to rainfall vary between burned and unburned catchments and between snow zones, and (2) identify the factors that affect these responses. We evaluated whether differences in storm hydrograph peak flow, total flow, stage rise, and lag to peak time differed by snow zone and burn category using generalised linear models. Additional predictors in these models are the maximum 60-min rainfall intensity for each storm, the cumulative potential water deficit prior to the storm, and the year post-fire. These models showed that the high snow zone (HSZ) has higher total stormflow than the low snow zone (LSZ), likely due to the higher soil moisture content in that area. In both snow zones, the biggest driver of the magnitude of the stormflow response was MI₆₀. Burn category did not have a clear impact on stormflow response in the HSZ, but it did impact stage rise at the severely burned catchment in the LSZ. This was the only site that had widespread overland flow post-fire. These results demonstrate that the stormflow responses to fire vary between snow zones, indicating a need to account for elevation and snow persistence in post-fire risk assessments.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70151","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919553","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":"Storage Dynamics and Groundwater–Surface Water Interactions in a Drought Sensitive Lowland Catchment: Process-Based Modelling as a Learning Tool","authors":"Zhengtao Ying,&nbsp;Doerthe Tetzlaff,&nbsp;Jean-Christophe Comte,&nbsp;Songjun Wu,&nbsp;Chris Soulsby","doi":"10.1002/hyp.70141","DOIUrl":"https://doi.org/10.1002/hyp.70141","url":null,"abstract":"<p>Groundwater is a key strategic water resource in times of drought, yet climate and land use change are increasing threats; this means that quantitative understanding of groundwater dynamics in lowland catchments is becoming more urgent. Here, we used a spatially distributed numerical groundwater model to simulate seasonal and long-term changes in the spatio-temporal patterns of water storage dynamics and groundwater–surface water interactions in the 66 km² lowland Demnitzer Millcreek catchment (DMC) in NE Germany. DMC experienced a long period of drought following the hot, dry summer of 2018, with groundwater stores becoming depleted and stream flows increasingly intermittent. The architecture and parameterisation of the model domain were based on groundwater observations, hydrogeological mapping and geophysical surveys. Weekly simulations using a single model layer with a 50 × 50 m grid of 15 m depth were able to broadly reproduce observed shallow groundwater dynamics in glacial and post-glacial deposits across the catchment. We showed that most groundwater flow is shallow and focused around topographic convergence zones fringing the channel network in more permeable glaciofluvial deposits. Most stream flow is generated by shallow groundwater in the catchment headwaters, which is relatively young (i.e., ~5 years old). With potential evapotranspiration rates exceeding precipitation, the groundwater balance is very sensitive to hydroclimate at DMC. The past two decades have been dominated by negative anomalies in annual rainfall, causing a general lowering of water tables and persistent storage deficits. Spatio-temporal patterns of recharge are also strongly influenced by vegetation cover, with coniferous forests, in particular, having high evapotranspiration losses that inhibit groundwater recharge. This underlines the importance of developing integrated land and water management strategies in NE Germany where climate change is expected to further reduce rainfall, increase temperatures and decrease groundwater recharge. For an evidence base to guide policy, we need to develop more robust ways to interface groundwater models with ecohydrological models to better characterise the impacts of land use on rechange in groundwater-dominated lowland catchments.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70141","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919509","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":"Tidal Dynamics in Coastal Karst Caves: Contributions to Coastal Hydrology and Historical Relative Sea-Level Reconstruction Using Phreatic Overgrowths on Speleothems in the Eastern Adriatic","authors":"Nina Lončar,&nbsp;Sanja Faivre,&nbsp;Blaž Miklavič,&nbsp;Marko Baričević","doi":"10.1002/hyp.70148","DOIUrl":"https://doi.org/10.1002/hyp.70148","url":null,"abstract":"<p>This study explores the hydraulic relationship between marine tides and groundwater levels in Medvjeđa špilja Cave on Lošinj Island, northern Adriatic, Croatia. Using water level loggers in the cave pool and adjacent sea, we recorded a peak tidal lag of 20–30 min and nearly identical amplitudes, confirming a strong hydraulic connection driven by the cave's proximity to the sea and high hydraulic conductivity. To complement this, geochemical parameters such as dissolved oxygen and pH were measured to assess the mixing of seawater and freshwater within the cave system and its response to tidal forces. Seasonal monitoring revealed notable tidal amplitude variations, with the largest observed in autumn, indicating the importance of this period for future studies. Tidal variations influenced the mixing of oxygenated seawater into the cave system, as reflected in dissolved oxygen levels, while stable pH values highlighted the buffering capacity of the system. These findings suggest that Medvjeđa špilja Cave holds significant potential for reconstructing historical sea levels using phreatic overgrowths on speleothems (POS). As the first study of its kind in the Adriatic, this research provides a methodological framework for analysing tidal dynamics in coastal karst systems. It emphasises the importance of high-resolution monitoring for understanding coastal aquifers and the potential of such studies to inform sea-level reconstructions in changing environmental conditions.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70148","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919554","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":"Assessment of Saturated Hydraulic Conductivity-Depth Relationships and Extended Soil Column Thickness in Catchment Hydrological Modelling","authors":"Raul Mendoza,&nbsp;Willem van Verseveld,&nbsp;Chris Seijger,&nbsp;Albrecht Weerts","doi":"10.1002/hyp.70149","DOIUrl":"https://doi.org/10.1002/hyp.70149","url":null,"abstract":"<p>An appropriate soil configuration is essential in hydrological models given the role of subsurface processes in the hydrological functioning of a catchment. Hydrological models are typically set up with shallow soil depths as restricted by measurements and soil datasets that are often unavailable in greater depths. While this may be sufficient for some catchments, in some areas the water table is located deeper and thus the shallow groundwater and its link with the rest of the hydrological processes may not be captured well by the model. An important soil parameter, that is known to vary with soil depth, is the saturated hydraulic conductivity (<i>K</i>_sat). In this study, we assessed different vertical profiles of <i>K</i>_sat which exceed the typical soil measurement depths. The <i>K</i>_sat profiles were implemented in wflow.jl for the distributed hydrological model wflow_sbm and tested for the Vecht catchment. Results demonstrated that increasing the soil thickness and implementing any of the <i>K</i>_sat profiles assessed improved the discharge and mean groundwater depth predictive capabilities, albeit altering the groundwater dynamics. A sensitivity analysis revealed the respective influence of four model parameters on the groundwater dynamics which can be used as basis to optimise the model performance further.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70149","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919328","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":"Regional-Scale Effects of Glacial Till Aquitard Vertical Heterogeneity on Transient Well Flow and Groundwater Budget With Variable Discharge in Leaky Aquifer Systems","authors":"Yabing Li,&nbsp;Zhifang Zhou,&nbsp;Ning Zhang","doi":"10.1002/hyp.70147","DOIUrl":"https://doi.org/10.1002/hyp.70147","url":null,"abstract":"<div>\u0000 \u0000 <p>In Pleistocene glacial regions, glacial till aquitards typically exhibit a significant regional-scale decrease in hydraulic parameters, such as specific storage (<i>S</i>_<i>s</i>) and hydraulic conductivity (<i>K</i>), with depth due to increased sediment compaction, reduced porosity, and lower pore connectivity. Pumping rates also decrease over time due to equipment wear and hydraulic friction. This study developed a novel analytical model for variable groundwater discharge in a leaky aquifer system, incorporating the often-overlooked vertical heterogeneity of aquitards. The model integrates two exponential decay mechanisms: one for the aquitard <i>S</i>_<i>s</i> and <i>K</i> with depth, and one for the pumping rates over time. Special cases addressing only depth-decaying <i>S</i>_<i>s</i>, depth-decaying <i>K</i>, or constant rates were also derived. New analytical solutions investigate how the decay exponents of aquitard <i>S</i>_<i>s</i> and <i>K</i>, variable pumping rates, and aquitard thickness influence drawdown and groundwater budgets. Results reveal that variable pumping rates cause local maxima and minima in aquifer drawdown, especially with higher decay of <i>S</i>_<i>s</i> and <i>K</i>. While aquitard thickness and pumping rates affect depletion and leakage, changes in the physical properties of aquitards, such as the decay of <i>S</i>_<i>s</i> and <i>K,</i> are more critical in determining the actual patterns of depletion and leakage fractions. Larger <i>S</i>_<i>s</i> decay or smaller <i>K</i> decay enhance early peak depletions caused by time-decaying pumping rates. These results highlight the importance of prioritising depth-dependent parameters in groundwater management, particularly in regions with significant vertical heterogeneity, like glacial deposits. The study offers valuable insights for hydrological assessments and optimising groundwater resource management in similar settings.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143914516","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":"Regional Differences in High Elevation Snowpack Decline Along the North American Rocky Mountains","authors":"Karen P. Zanewich,&nbsp;Stewart B. Rood","doi":"10.1002/hyp.70153","DOIUrl":"https://doi.org/10.1002/hyp.70153","url":null,"abstract":"<p>The Rocky Mountains (RM) provide the ‘water towers’ for western North America, with deep winter snowpack accumulations that melt to contribute flows for the extensively utilised Columbia, Colorado, Saskatchewan, Missouri and Rio Grande River systems. With climate change, winter and spring warming are increasing seasonal and elevational rain versus snow proportions and altering the annual patterns of snowpack accumulation and melt. Prior studies have reported declines in snowpack extent or water content, especially on an index date, April 1. These declines could reflect reductions in the total annual snowpacks or earlier transitions to snowmelt. To resolve these influences, we assessed daily snowpack patterns at 314 snow pillow stations in the higher elevations along the 2500 km transboundary RM corridor, over three decades from 1991 to 2020. We found regional differentiation, with little change in the maximum snow water equivalent (SWE_max) or its timing (Day_max) in the most-northerly, Canadian RM region (BC, AB); slight declines in the Northern US (ID, MT, WY) and Central US (UT, CO); and major declines in the Southern US (AZ, NM; average ΔSWE_max: −2%/yr; ΔDay_max: −0.75%/yr). With compound influences of declining SWE_max and earlier Day_max, the April 1 SWE (SWE_Apr1) was more responsive, with progressive decline at some Northern US and Central US stations, and steep decline in the Southern US region (ΔSWE_Apr1: −6.5%/yr). Due to these compound influences, we recommend that future analyses include snowpack maxima and seasonality as well as April 1 measures, since that precedes the peak snowpack for higher elevation and northern sites, but follows the peak for lower and southern sites, confounding trend comparisons. Thus, higher elevation RM snowpacks are declining but with considerable latitudinal variation, displaying slight change in magnitude and seasonality in the northern regions, and greater change southward. These patterns contrast with some other climate change patterns that display increasing responsivity with higher latitude.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70153","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143914057","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}