地球科学最新文献

{"title":"Energetic Electron Diffusion and Precipitation Driven by Ducted Hiss Waves in High Density Irregular Region","authors":"Bopu Feng,&nbsp;Haimeng Li,&nbsp;Rongxin Tang,&nbsp;Meng Zhou,&nbsp;Zhihai Ouyang,&nbsp;Zhigang Yuan,&nbsp;Dedong Wang,&nbsp;Xiongdong Yu,&nbsp;Ying Xiong,&nbsp;Zhou Chen,&nbsp;An Yuan,&nbsp;Yingqiao Cheng","doi":"10.1029/2025GL115107","DOIUrl":"https://doi.org/10.1029/2025GL115107","url":null,"abstract":"<p>Plasmaspheric hiss plays an important role in the electron precipitation and the slot formation in radiation belts. Recent studies show the whistler-mode waves can be guided in the density irregularities, performing parallel propagation. Therefore, the resonance between ducted waves and energetic electrons can expand to higher latitudes, and then drive strong energetic electron scattering. In this study, we report a conjugate observation using data from Van Allen Probe A and POES. Through the analysis of observation and the quantification of quasi-linear diffusion coefficients, the results show the ducted hiss can effectively scatter the energetic electrons and drive enhanced electron flux at low altitude region. We suggest the ducted hiss is important for electron loss process in radiation belts.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL115107","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143740966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Severe Extreme Cold Event in Beijing-Tianjin-Hebei Region Tied to Mid-High-Latitude Intraseasonal Waves","authors":"Tao Zhu,&nbsp;Yiruo Zhou,&nbsp;Jing Yang,&nbsp;Frederic Vitart,&nbsp;Qing Bao","doi":"10.1029/2024GL113745","DOIUrl":"https://doi.org/10.1029/2024GL113745","url":null,"abstract":"<p>Extreme cold events (ECEs) have intensified in East Asia over the past decades, disrupting socio-economic activities and public health. Understanding the mechanism and accurate prediction are crucial yet challenging. This study explores the causes and prediction biases for a severe ECE in Beijing-Tianjin-Hebei (BTH) during the 2022 Winter Olympics. Two upper-tropospheric quasi-biweekly oscillations (QBWO), propagating eastward along the mid- and high-latitudes, respectively, have been confirmed to trigger a low-tropospheric cyclonic anomaly (LCA) via potential vorticity advection and meridional secondary circulation. This LCA generated the BTH ECE by reducing incoming solar radiation due to increased snowfall and cloud cover, and by advecting cold air into BTH. Both the subseasonal dynamical prediction and long-term historical observational diagnosis further indicate a strong connection between mid-high-latitude QBWO and the regional ECEs. This research deepens our understanding of the ECE mechanisms and underscores the need for improving the prediction of extratropical subseasonal signals for better forecasting of extreme events.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL113745","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143741359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Diachronous Accumulation of Mid-Pleistocene Gravel Beds Driven by Tectonics Across the Tibetan Plateau","authors":"Yizhou Yang,&nbsp;Feng Cheng,&nbsp;Rongzhang Zheng,&nbsp;Luying Peng,&nbsp;Kexin Yi,&nbsp;Jiawei Wu,&nbsp;Zhaojie Guo","doi":"10.1029/2024GL110750","DOIUrl":"https://doi.org/10.1029/2024GL110750","url":null,"abstract":"<p>Deciphering how the widespread late Cenozoic conglomerates were formed across the Tibetan Plateau is crucial for understanding the competition between tectonics and climate. Here we target the mid-Pleistocene conglomerate cap along the northern Saishiteng range (SR), North Tibet. ²⁶Al/¹⁰Be burial dating constrains the onset accumulation of the conglomerate cap to 828 ⁺¹¹⁶/₋₁₀₅ to 679 ^+55.0/_−51.1 kyr ago. Newly-discovered seismites and localized unconformities indicate the mid-Pleistocene growth of the SR, leading to accumulation of the conglomerate cap. Integrating our new observation with previous studies on other gravel beds across the Tibetan Plateau, we reveal diachronous depositional ages of these gravel beds ranging from 1.37 to 0.56 Myr. Given the spatial and temporal distribution patterns of gravel beds, we infer that tectonic uplift primarily governed the accumulation of the low-elevation (&lt;2,400 m) gravel beds, whereas the interplay between tectonics and climate change shaped most high-elevation (&gt;2,400 m) gravel beds across the plateau.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL110750","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143741364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Palaeoecology of the Pliocene large carnivore guild at Hadar, Lower Awash Valley, Ethiopia","authors":"Joshua R. Robinson ,&nbsp;Ignacio A. Lazagabaster ,&nbsp;John Rowan ,&nbsp;Margaret E. Lewis ,&nbsp;Lars Werdelin ,&nbsp;Christopher J. Campisano ,&nbsp;Kaye E. Reed","doi":"10.1016/j.jhevol.2025.103653","DOIUrl":"10.1016/j.jhevol.2025.103653","url":null,"abstract":"<div><div>The Hadar Formation at Hadar (Lower Awash Valley, Ethiopia, ∼3.45–2.95 Ma) is one of the most well-known and studied Pliocene hominin-bearing sequences in eastern Africa, yielding numerous fossils of the species <em>Australopithecus afarensis</em>. While much research has been conducted on the palaeoecology of the Hadar Formation broadly, little attention has been placed on the carnivore guild. Here, we present new stable carbon and oxygen isotope data for Hadar carnivores that contribute to the palaeoenvironmental reconstructions of the Hadar Formation and facilitate inference of predator-prey relationship between the large carnivore and herbivore guilds at Hadar. Overall, the members of the Hadar carnivore guild had relatively high carbon values (−4.6 ± 1.4‰), with the highest values in the middle part of the sequence (Denen Dora Member, ∼3.2 Ma). These values are higher than the carbon values of carnivores from penecontemporaneous sediments in the Turkana Basin (southern Ethiopia and northern Kenya). Stable oxygen isotope values are variable throughout the Hadar Formation, but reconstruction of estimated meteoric water oxygen values indicates a wetter and more pluvial climate than that at the present. Carbon isotope mixing models weighted by a prey selectivity index based on established predator-prey body size relationships reveals that two large-bodied taxa (<em>Homotherium</em> and <em>Crocuta venustula</em>) had partitioned their dietary niches only to a limited extent. Understanding the nature of the large carnivore guild at Hadar allows us to predict which taxa may have been competitors or predators of <em>Au. afarensis</em>, offering insights into the palaeoecological context beyond what can be inferred from palaeoenvironmental reconstructions alone. Moreover, our analyses provide a valuable insight into the little-known isotopic ecology of fossil African carnivores.</div></div>","PeriodicalId":54805,"journal":{"name":"Journal of Human Evolution","volume":"202 ","pages":"Article 103653"},"PeriodicalIF":3.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controls From Above and Below: Snow, Soil, and Steepness Drive Diverging Trends of Subsurface Water and Streamflow Dynamics","authors":"Devon Kerins,&nbsp;Abigail S. Knapp,&nbsp;Fiona S. Liu,&nbsp;Valerie Diana Smykalov,&nbsp;Matthew P. Berzonsky,&nbsp;Andrew Vierbicher,&nbsp;Kayalvizhi Sadayappan,&nbsp;Bryn Stewart,&nbsp;Elizabeth M. Andrews,&nbsp;Pamela L. Sullivan,&nbsp;Holly R. Barnard,&nbsp;Jan Seibert,&nbsp;Lauren E. McPhillips,&nbsp;Kamini Singha,&nbsp;Li Li","doi":"10.1002/hyp.70120","DOIUrl":"https://doi.org/10.1002/hyp.70120","url":null,"abstract":"<p>The importance of subsurface water dynamics, such as water storage and flow partitioning, is well recognised. Yet, our understanding of their drivers and links to streamflow generation has remained elusive, especially in small headwater streams that are often data-limited but crucial for downstream water quantity and quality. Large-scale analyses have focused on streamflow characteristics across rivers with varying drainage areas, often overlooking the subsurface water dynamics that shape streamflow behaviour. Here we ask the question: <i>What are the climate and landscape characteristics that regulate subsurface dynamic storage, flow path partitioning, and dynamics of streamflow generation in headwater streams?</i> To answer this question, we used streamflow data and a widely-used hydrological model (HBV) for 15 headwater catchments across the contiguous United States. Results show that climate characteristics such as aridity and precipitation phase (snow or rain) and land attributes such as topography and soil texture are key drivers of streamflow generation dynamics. In particular, steeper slopes generally promoted more streamflow, regardless of aridity. Streams in flat, rainy sites (&lt; 30% precipitation as snow) with finer soils exhibited flashier regimes than those in snowy sites (&gt; 30% precipitation as snow) or sites with coarse soils and deeper flow paths. In snowy sites, less weathered, thinner soils promoted shallower flow paths such that discharge was more sensitive to changes in storage, but snow dampened streamflow flashiness overall. Results here indicate that land characteristics such as steepness and soil texture modify subsurface water storage and shallow and deep flow partitioning, ultimately regulating streamflow response to climate forcing. As climate change increases uncertainty in water availability, understanding the interacting climate and landscape features that regulate streamflow will be essential to predict hydrological shifts in headwater catchments and improve water resources management.</p>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 4","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70120","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749534","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":"Understanding Flow Transport in Dual-Water-Source Rivers: Enhancing Storage Selection Functions With Two-Gamma Distributions","authors":"Anran Liao,&nbsp;Tiantian Zhou,&nbsp;Xianfang Song,&nbsp;Lihu Yang,&nbsp;Dongmei Han,&nbsp;Shengtian Yang","doi":"10.1002/hyp.70121","DOIUrl":"https://doi.org/10.1002/hyp.70121","url":null,"abstract":"<div>\u0000 \u0000 <p>Modelling solute transport in river systems using the Storage Selection (SAS) function presents challenges when solute recharge originates from two distinct water sources: a point reclaimed-water source (perpendicular to gravity) and a surface rainfall source (parallel to gravity). This study introduces three modifications to the original SAS function to address dual-source transport dynamics in a reclaimed-water-source river reach: (i) incorporating rainwater into the reclaimed water flux (<i>R</i>), (ii) introducing a mixing process to represent interactions between rainwater and reclaimed water (Mix), and (iii) modifying the original SAS function into a two-gamma-distribution (2GM) model to better capture dual-source transport behaviour. The effects of these modifications were evaluated individually and in combination. Among the modifications, the 2GM model achieved the highest increase in the Nash-Sutcliffe efficiency coefficient (NSE), followed by R and then Mix. The 2GM model regulated storage volume, thereby influencing the outflow δ²<i>H</i> value (i.e., the objective function), making it the most effective modification. Combining all modifications produced the best model performance, improving NSE from 0.61 to 0.86. However, short-term δ²<i>H</i> fluctuations due to river morphology-induced stochastic processes were not captured by this lumped transport model. The optimal model indicated that storm events significantly accelerated river water (mixed reclaimed water and rainwater) mobility. One day after rainfall, 53% of the water at the outlet originated from event water, either from adjacent sites or nearby subsurface flow. Subsequent rainwater and reclaimed water flowed out gradually at a very slow rate. River storage received sustained event water throughout the wet period, with most event water stagnating in storage, except for outflow occurring 1 day post-rainfall. Special attention should be given to pollutants carried by event water and the associated aquatic risks during wet periods in megacities. This study provides a reference for flood management and pollution control.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 4","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749535","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":"Culture énéolithique de Botaï-Tersek au Kazakhstan septentrional","authors":"Sergey V. Zakharov","doi":"10.1016/j.anthro.2025.103363","DOIUrl":"10.1016/j.anthro.2025.103363","url":null,"abstract":"<div><div>The final period of the Palaeolithic in Northern Kazakhstan is highly represented by Eneolithic sites of the Botai-Tersek culture. This paper provides an overview and principal information on the material criteria of this culture. The major sites are the Botai, the Krasnyj Yar I, the Vasilkovka IV, the Kozhai 1 and the Kumkeshu 1. They are situated in two regions bordering Northern Kazakhstan. These are the Turgay depression and the north-western part of the Sary-Arka region. These large sites were occupied for a long time. They are represented by dozens and hundreds of semi-buried habitats. The faunal assemblage from the major sites is predominated by horse bones. The material is best represented by lithic and bone tools, ceramics and engraved phalanges of horses and other ungulate species. The collections are abundant and very diversified. The knapping is based both on the production of flake tools and bifacial retouching. The collections are dominated by lithic and bone tools for hunting and for treatment of raw materials of animal origin. The round-based, low-streamlined ceramic vessels are decorated with geometric compositions with straight lines. The major questions are about the development and origine of the Botai-Tersek culture.</div></div>","PeriodicalId":46860,"journal":{"name":"Anthropologie","volume":"129 2","pages":"Article 103363"},"PeriodicalIF":0.6,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal Source Water Changes and Winds Contribute to the Development of Hypoxia in St Helena Bay Within the Southern Benguela Upwelling System","authors":"A. J. Carlson,&nbsp;S. A. Siedlecki,&nbsp;J. Granger,&nbsp;J. Veitch,&nbsp;G. C. Pitcher,&nbsp;G. Fearon,&nbsp;F. Soares,&nbsp;M. Zhou,&nbsp;R. F. Flynn,&nbsp;S. E. Fawcett","doi":"10.1029/2024JC021702","DOIUrl":"https://doi.org/10.1029/2024JC021702","url":null,"abstract":"<p>St Helena Bay (SHB), a retentive zone in the productive southern Benguela Upwelling System off western South Africa, experiences seasonal hypoxia and episodic anoxic events that threaten local fisheries. To understand the drivers of oxygen variability in SHB, we queried 25 years of dissolved oxygen (DO) observations alongside high-resolution wind and hydrographic data, and dynamical data from a high-resolution model. At 70 m in SHB (mid-bay), upwelling-favorable winds in spring drove replenishment of cold, oxygenated water. Hypoxia developed in summer, becoming most severe in autumn. Bottom waters in autumn were replenished with warmer, less oxygenated water than in spring—suggesting a seasonal change in source waters upwelled into the bay. Downwelling and deep mixing in winter ventilated mid-bay bottom waters, which reverted to hypoxic conditions during wind relaxations and reversals. In the nearshore (20 m), hypoxia occurred specifically during periods of upwelling-favorable wind stress and was most severe in autumn. Using a statistical model, we extended basic hydrographic observations to nitrate and DO concentrations and developed metrics to identify the accumulation of excess nutrients on the shelf and nitrogen-loss to denitrification, both of which were most prominent in autumn. A correspondence of the biogeochemical properties of hypoxic waters at 20 m to those at 70 m implicates the latter as the source waters upwelled inshore in autumn. We conclude that wind-driven upwelling drives the replenishment of respired bottom waters in SHB with oxygenated waters, noting that less-oxygenated water is imported later in the upwelling season, which exacerbates hypoxia.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143740976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact-Based Thresholds for Investigation of High-Tide Flooding in the United States","authors":"Christopher G. Piecuch,&nbsp;Sarah B. Das,&nbsp;Levi Gorrell,&nbsp;Sönke Dangendorf,&nbsp;Benjamin D. Hamlington,&nbsp;Philip R. Thompson,&nbsp;Thomas Wahl","doi":"10.1029/2024EF005850","DOIUrl":"https://doi.org/10.1029/2024EF005850","url":null,"abstract":"<p>High-tide flooding—minor, disruptive coastal inundation—is expected to become more frequent as sea levels rise. However, quantifying just how quickly high-tide flooding rates are changing, and whether some places experience more high-tide flooding than others, is challenging. To quantify trends in high-tide flooding from tide-gauge observations, flood thresholds—elevations above which flooding begins—must be specified. Past studies of high-tide flooding in the United States have used different data sets and approaches for specifying flood thresholds, only some of which directly relate to coastal impacts, which has lead to sometimes conflicting and ambiguous results. Here we present a novel method for quantifying, with uncertainty, high-tide flooding thresholds along the United States coast based on sparsely available impact-based flood thresholds. We use those newly modeled thresholds to make an updated assessment of changes in high-tide flooding across the United States over the past few decades. From 1990–2000 to 2010–2020, high-tide flooding rates almost certainly (probability <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>P</mi>\u0000 <mo>&gt;</mo>\u0000 <mn>99</mn>\u0000 <mi>%</mi>\u0000 </mrow>\u0000 <annotation> $P &gt; 99%$</annotation>\u0000 </semantics></math>) increased along the United States East Coast, Gulf Coast, California, and Pacific Islands, while they very likely <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mrow>\u0000 <mi>P</mi>\u0000 <mo>=</mo>\u0000 <mn>93</mn>\u0000 <mi>%</mi>\u0000 </mrow>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation> $(P=93%)$</annotation>\u0000 </semantics></math> decreased along Alaska during that time; significant changes in high-tide flooding rates between the two decades were not detected in Oregon, Washington, and the Caribbean. Averaging spatially, we find that high-tide flooding rates probably <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mrow>\u0000 <mi>P</mi>\u0000 <mo>=</mo>\u0000 <mn>85</mn>\u0000 <mi>%</mi>\u0000 </mrow>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation> $(P=85%)$</annotation>\u0000 </semantics></math> more than doubled nationally between 1990–2000 and 2010–2020. Our approach lays a foundation for future studies to more accurately model high-tide flood thresholds and trends along the global coastline.</p>","PeriodicalId":48748,"journal":{"name":"Earths Future","volume":"13 4","pages":""},"PeriodicalIF":7.3,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EF005850","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Optimizing flood resilience in China’s mountainous areas: Design flood estimation using advanced machine learning techniques","authors":"Xuemei Wang ,&nbsp;Ronghua Liu ,&nbsp;Chaoxing Sun ,&nbsp;Xiaoyan Zhai ,&nbsp;Liuqian Ding ,&nbsp;Xiao Liu ,&nbsp;Xiaolei Zhang","doi":"10.1016/j.ejrh.2025.102345","DOIUrl":"10.1016/j.ejrh.2025.102345","url":null,"abstract":"<div><h3>Study region</h3><div>China</div></div><div><h3>Study focus</h3><div>We developed machine learning (ML) models for design flood estimation in mountainous catchments (≤ 500 km²) across China. This process considered different ML algorithms (random forest, extreme gradient boosting, and support vector regression), model scopes (nation and hydrological zones), and feature input sets (1–14 features) to optimize model development strategies.</div></div><div><h3>New hydrological insights for the region</h3><div>Based on estimation performance and hyperparameter tuning efficiency, random forest was found to be the optimal algorithm. The optimal model scope resulted in five distinct models: a single lumped model encompassing six eastern zones and four separate zonal models for the western zones. Considering both accuracy and efficiency, the optimal number of input features ranged from 5 to 14 for different models. High estimation accuracy was observed in the Qinba-Dabie North, Southeast, Southwest, and Yunnan-Tibet Zone, with average <em>RMSE</em>, <em>R</em>², <em>MQE</em>, and <em>QR</em> ranging from 55.90 to 103.97, 0.83–0.93, 45.62–65.77 %, and 55.90–60.98 %, respectively, for the test set across different return periods. The remaining zones exhibited moderate accuracy, with the Northwest Basin Zone demonstrating particularly low accuracy due to fewer catchments. Notably, catchments with areas &gt; 100 km² demonstrated higher estimation accuracy, with an average 60 % reduction in <em>MQE</em> and a 30 % increase in <em>QR</em> compared to catchments of all sizes. This study provides crucial reference and data support for national flash flood prevention efforts.</div></div>","PeriodicalId":48620,"journal":{"name":"Journal of Hydrology-Regional Studies","volume":"59 ","pages":"Article 102345"},"PeriodicalIF":4.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143748318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}