Hydrological Processes最新文献

{"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}

{"title":"Influence of Sub-Cloud Evaporation on Precipitation Isotopes: Insights From Hourly-Scale Meteorological Assessment in a Large Lake in the East Asian Monsoon Region","authors":"Shiyong Tao,&nbsp;Jing Xu,&nbsp;Junqiang Xia,&nbsp;Yang Xiao","doi":"10.1002/hyp.70152","DOIUrl":"https://doi.org/10.1002/hyp.70152","url":null,"abstract":"<div>\u0000 \u0000 <p>Sub-cloud evaporation is a critical aspect of the hydrological cycle, reducing surface precipitation totals and altering the stable isotopic composition as raindrops fall from the cloud base towards the surface. However, isotopic modelling of sub-cloud evaporation in humid climates and its implications for hydrological processes remain poorly understood, posing challenges for regional water resource management and ecological conservation. In this study, a comprehensive assessment was conducted to understand the influence of sub-cloud evaporation on precipitation isotopes in Poyang Lake, the largest freshwater lake in China. Using 4-year hourly meteorological observations from 11 national meteorological stations, we found that there was significant sub-cloud evaporation during the precipitation process in humid regions. The remaining fraction of evaporated raindrops varied between 81% and 95%, with the lowest values occurring in September and the highest in February. The monthly average ∆δ²H, ∆δ¹⁸O and ∆d-excess values ranged from 2.9‰ to 7.0‰, 0.7‰ to 1.8‰, and −7.7‰ to −2.8‰, respectively, and the sub-cloud evaporation effect during the rainy season was more intense than that during the dry season. By modifying the sub-cloud evaporation effect, precipitation isotopes monitored at the surface and estimated at the cloud base were confirmed to exhibit consistent temporal patterns on both monthly and daily scales. Sensitivity analysis revealed that precipitation isotopic changes were more sensitive to fluctuations in relative humidity and precipitation intensity under varying meteorological scenarios. The underrepresentation of low-intensity precipitation events was found to lead to a statistical underestimation of precipitation isotopic changes, and when the low-intensity events (≤ 1.0 mm/h) were excluded, the average ∆δ¹⁸O and ∆d-excess values shifted from 1.25‰ and −5.25‰ to 0.63‰ and −2.72‰, respectively. These findings contribute to a better understanding of hydrological cycle processes in Poyang Lake and other regions with similar humid climate characteristics, especially for the interpretation of regional paleohydrological records and ecohydrological mechanisms using stable isotopes.</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":"143914518","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":"Hydrological Implications of Urban Vegetation and Energy Dynamics in Heat and Climate Adaptation","authors":"Nurul Syahira Mohammad Harmay,&nbsp;Minha Choi","doi":"10.1002/hyp.70139","DOIUrl":"https://doi.org/10.1002/hyp.70139","url":null,"abstract":"<div>\u0000 \u0000 <p>This research paper investigates the interplay between urban vegetation, surface energy fluxes, and hydrological processes in mitigating heat and adapting to global warming. Through climate model simulation, this study explored how vegetation coverage (measured by leaf area index, LAI) and the impervious surface fraction (<i>f</i>_imp) influence hydrological dynamics, urban heat island (UHI), and energy fluxes across various climate zones within Asian cities for the period of 2000 to 2014. Kuala Lumpur and Singapore (tropical rainforest) showed significant increasing UHI trends of 0.319°C and 0.271°C/month, respectively. Bangkok and Ho Chi Minh (tropical savanna) showed a negative correlation between LAI and temperature (UHI) of −0.31 (−0.57), indicating the cooling effects of vegetation through evapotranspiration. In tropical rainforest climates, a strong positive correlation between LAI and latent heat flux highlights the critical role of water availability in modulating hydrological cycles and vegetation dynamics. Humid continental/subtropical climates showed a positive correlation between LAI and sensible heat flux, highlighting the influence of sensible heat exchange on vegetation growth. A positive correlation was demonstrated between energy fluxes and <i>f</i>_imp across all climate zones, indicating that urbanisation intensifies hydrological disruptions, exacerbating the UHI effect. This study emphasises the importance of integrating hydrological insights into urban vegetation strategies for effective heat mitigation and climate adaptation.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143905017","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":"Multivariate Drought Characteristics and Joint Probability Analysis Under Climate Change: A Comparative Index-Based Study in Korea","authors":"Sayed Shah Jan Sadiqi,&nbsp;Eun-Mi Hong,&nbsp;Won-Ho Nam,&nbsp;Taegon Kim","doi":"10.1002/hyp.70144","DOIUrl":"https://doi.org/10.1002/hyp.70144","url":null,"abstract":"<div>\u0000 \u0000 <p>This study analyses the impact of climate change on drought occurrence in the Doam Watershed using three distinct drought indices: precipitation, temperature and soil moisture. Historical data reveal shifting drought patterns influenced by changing hydrological conditions and precipitation variability. The Standardised Precipitation Index (SPI) and Standardised Precipitation Evapotranspiration Index (SPEI) indicate a trend towards more severe droughts in spring and winter, with less severity in summer. However, the Palmer Drought Severity Index (PDSI) shows increasing severity and longer duration for droughts from winter to spring. The periodicity of drought recurrence ranges from three to 6 years, with SPI3 indicating a short interval of approximately 1 year, SPI6 and SPI12 cycles of 4–6 years and PDSI a cycle of about 6 years. Future projections suggest that droughts will become more severe and persistent, particularly, under the SSP585 scenario. Joint return period analysis highlights an increased likelihood of future droughts, with shorter return periods for specified severity or duration compared to historical data. Drought severity data fit best with a log-normal distribution, while drought duration data follow an exponential distribution. Copula-based joint distribution functions were developed, with Frank and normal copula functions selected based on evaluation criteria. These models facilitated a deeper analysis of the interdependence between drought severity and duration. The findings emphasise the need for targeted measures to address annual winter and spring droughts, as well as large-scale, extreme droughts recurring approximately every 6 years.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 5","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143905007","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}