{"title":"ScS Reverberations Map Widespread Subducted Slab Stagnation in the Mantle Transition Zone","authors":"Rashni Anandawansha, Lauren Waszek, Benoit Tauzin","doi":"10.1029/2025JB031726","DOIUrl":"10.1029/2025JB031726","url":null,"abstract":"<p>Earth's mantle transition zone (MTZ) is a region of substantial transformations in the structure and composition of rocks. The mineralogical phase changes, observed seismically as semi-discontinuous features, act as a semi-permeable barrier to thermochemical flux between the upper and lower mantle. They partly control global mantle circulation patterns. However, understanding regional-scale convection processes relies on high-quality seismic measurements with improvements in observational approaches in terms of coverage and resolution. Here, we perform a comprehensive analysis of the MTZ discontinuities using new large global data sets of ScS reverberations. The data sets are compiled and processed using data-driven and machine learning methodologies, highlighting the prospective capacity of automated approaches for rapid data analysis. Our maps reveal significant topography variations in the 410 and 660 km discontinuity depths, and hence MTZ thickness, and provide complementary spatial geometry to existing MTZ maps. These results are consistent with first order correlation of MTZ thickness with seismic wavespeed, and further indicate additional smaller scale lateral variation in topography across all regions of data coverage. We integrate our observations with mineralogical modeling to derive new thermal and compositional models of the MTZ. Our models display a correlation between locations of recent subduction and basalt accumulation, and between hotspots and regions of high temperature. Both temperature and composition are dominated by short-length scale patterns in their variability, indicating ubiquitous and persistent heterogeneities within the MTZ. Together, these observations evidence widespread and long-term stagnation of material at and within the MTZ.</p>","PeriodicalId":15864,"journal":{"name":"Journal of Geophysical Research: Solid Earth","volume":"130 10","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261598","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}
Molly Asher , Jonas Wied Pedersen , Steven Böing , Cathryn Birch , Mark Trigg , Elizabeth Kendon
{"title":"Extreme rainfall and temporal loading in Great Britain: Analysis of present and future trends using a convection-permitting climate model","authors":"Molly Asher , Jonas Wied Pedersen , Steven Böing , Cathryn Birch , Mark Trigg , Elizabeth Kendon","doi":"10.1016/j.ejrh.2025.102750","DOIUrl":"10.1016/j.ejrh.2025.102750","url":null,"abstract":"<div><h3>Study Region:</h3><div>Great Britain</div></div><div><h3>Study Focus:</h3><div>While climate change is intensifying rainfall extremes, its effect on temporal loading remains poorly understood. Temporal loading, the distribution of rainfall over storm duration, influences flood risk for storms of a given volume and is critical for urban infrastructure planning. This research presents the first direct investigation of event temporal loading within climate projections, utilising UKCP Local convection-permitting ensemble simulations. At rain gauge locations, we sample the most extreme storm each year at durations from 1.5 to 24 hours and apply two classification metrics to evaluate storm temporal structure.</div></div><div><h3>New Hydrological Insights for the Region:</h3><div>Our analysis confirms that in today’s climate, shorter-duration storms tend to be front-loaded, while longer storms exhibit more centred, symmetrical intensity profiles. Spatial patterns emerge with central and southern England exhibiting a higher proportion of highly asymmetric events. However, no consistent changes in temporal loading are projected under future climates, challenging previous inferences based on temperature–rainfall relationships. These discrepancies may stem from differences in storm-generating mechanisms between Great Britain and tropical regions studied previously. Our findings highlight limitations of current metrics, which inadequately distinguish aspects of storm structure contributing to temporal loading. We recommend developing refined metrics to independently quantify event asymmetry, peak intensity, and timing. Such advancements are crucial for improving design flood modelling alongside future climate scenarios.</div></div>","PeriodicalId":48620,"journal":{"name":"Journal of Hydrology-Regional Studies","volume":"62 ","pages":"Article 102750"},"PeriodicalIF":5.0,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268803","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}
Katelyn McKindles, Kensuke Seto, D. Quynh Nguyen, Timothy Y. James, R. Michael McKay
{"title":"Temperature and light drive physiological and transcriptional responses, modulating infection outcomes in a freshwater diatom–chytrid system","authors":"Katelyn McKindles, Kensuke Seto, D. Quynh Nguyen, Timothy Y. James, R. Michael McKay","doi":"10.1002/lno.70224","DOIUrl":"https://doi.org/10.1002/lno.70224","url":null,"abstract":"<jats:italic>Stephanodiscus binderanus</jats:italic> is a bloom‐forming diatom abundant in winter and persisting into spring in the Laurentian Great Lakes. Climate change impacts these blooms by altering ice cover, turbidity, light penetration, and water temperature. Fungal parasites, especially <jats:italic>Chytridiomycota</jats:italic>, can suppress phytoplankton growth and alter bloom succession. To address the effects of both biotic and abiotic factors on <jats:italic>S. binderanus</jats:italic> in the face of a changing climate, we tested a range of temperatures (9.4–24°C) and light intensities (15, 30, 50, 100 <jats:italic>μ</jats:italic>mol m<jats:sup>−2</jats:sup> s<jats:sup>−1</jats:sup>) on infected and uninfected cultures. We also conducted an RNAseq analysis of both host and parasite across the described environmental parameters. <jats:italic>Stephanodiscus binderanus</jats:italic> can rapidly adapt to the above conditions, growing slowest at the lowest temperature and under low light, while adjusting its chlorophyll <jats:italic>a</jats:italic> (Chl <jats:italic>a</jats:italic>) content in lower light treatments to be more efficient at light harvesting. Chytrid infections were more prevalent at either end of the tested temperature range, despite downregulation of zoospore mitotic cycle genes at elevated temperatures. Elevated temperatures also induced reproductive stress in <jats:italic>S. binderanus</jats:italic>, marked by downregulation of meiosis‐related genes. These effects, combined with nutrient depletion, likely contribute to seasonal declines in diatom populations as green algae and cyanobacteria emerge in late spring and early summer. It is anticipated that host response to lower light availability and the ability of the chytrid to infect under warming waters will contribute to a decline in filamentous diatom biomass in Lake Erie, especially as climate change increases the frequency of ice‐free winters.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"72 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261581","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":"Effect of the driving process for construction of geotextile-encased columns on the deformation of soft foundation soils","authors":"H.P. Souza , G.L.S. Araújo , J.G. Zornberg , F.H.M. Portelinha","doi":"10.1016/j.geotexmem.2025.09.006","DOIUrl":"10.1016/j.geotexmem.2025.09.006","url":null,"abstract":"<div><div>The construction of geosynthetic encased columns for embankment support involving the tube driving technique may induce vertical and horizontal stresses throughout the soft soil foundation and neighboring columns, which is often not accounted for in design. Investigating this unknown effect is a difficult task for which the use of the transparent soil method is a promising tool when combined with Digital Image Correlation (DIC) techniques. This study investigates the effect of GEC column installation on the deformation of the soft foundation soil. The specific focus is on how the driving process affects the lateral and vertical deformations of the surrounding soft soil, as well as the interaction with neighboring columns. Different column configurations, spacing, and installation sequences were investigated. After evaluation and quantification of the deformation patterns, a methodology is proposed to study the extent of displacements caused by the tube's driving. Results showed that an increase in the spacing between columns reduced the influence of the tube's driving. Interestingly, adopting the alternating GEC installation may lead to higher lateral displacements than the sequential installation process. Increasing the number of GECs from three to four elements further reduced the displacements magnitude in the region adjacent to the first column installed.</div></div>","PeriodicalId":55096,"journal":{"name":"Geotextiles and Geomembranes","volume":"54 1","pages":"Pages 67-84"},"PeriodicalIF":6.2,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Veera Lipsanen, Lucile Turc, Sanni Hoilijoki, Denny M. Oliveira, Souhail Dahani, Shi Tao, Milla Kalliokoski, Mirja Ojuva, Emilia K. J. Kilpua
{"title":"Local Time Dependence of High-Latitude Pc5 Wave Activity Driven by Interplanetary Shocks and Foreshock Transients, Using a New ULF Index","authors":"Veera Lipsanen, Lucile Turc, Sanni Hoilijoki, Denny M. Oliveira, Souhail Dahani, Shi Tao, Milla Kalliokoski, Mirja Ojuva, Emilia K. J. Kilpua","doi":"10.1029/2025JA034378","DOIUrl":"https://doi.org/10.1029/2025JA034378","url":null,"abstract":"<p>We present a study of ground-based Pc5 ultra-low frequency (ULF) wave response to over 400 interplanetary (IP) shocks and 18 foreshock transients. We investigated the local time dependence of magnetospheric Pc5 wave power generated by IP shocks and foreshock transients and whether this dependence is related to the impact angle of IP shocks and impact point of foreshock transients. To study this, we created a new magnetic local time dependent high-latitude Pc5 ULF wave index using magnetic field measurements from high latitude magnetometers obtained from SuperMAG. Our findings indicate that the impact angle of an IP shock does not determine the location of the peak Pc5 power. However, we find that frontal shocks drive stronger wave power than inclined shocks. Shock speed and dynamic pressure ratio correlate moderately with the peak Pc5 power. During 61% of the studied foreshock transients, we observe a clear Pc5 response, that is, the wave power increased significantly. The distribution of Pc5 power is consistent with the propagation direction of the transients. The results suggest that the size of the foreshock transient and the solar wind speed may affect the observed Pc5 wave response. Although the Pc5 response to IP shocks and foreshock transients differ, foreshock transients can drive Pc5 wave power comparable to IP shocks.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 10","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JA034378","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145272358","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}
Patrizia Santi, Alberto Renzulli, Daniele Sacco, Anna Lia Ermeti, Erika Valli
{"title":"The Pietra Ollare of the medieval archaeological site of Monte Giove (Fano, Marche Region, Central Italy) unveils further constraints for the Alpine Valchiavenna soapstone trade","authors":"Patrizia Santi, Alberto Renzulli, Daniele Sacco, Anna Lia Ermeti, Erika Valli","doi":"10.1007/s12520-025-02315-2","DOIUrl":"10.1007/s12520-025-02315-2","url":null,"abstract":"<div><p>More than two hundred fragments of <i>pietra ollare</i> were discovered in the Monte Giove Medieval archaeological site as erratic pieces on the surface and within some of the 120 silos of underground pits for food storage, dated between the 9th and 11th centuries AD. Twelve representative samples were selected for thin section petrography, X-ray powder diffraction and whole rock major-trace element composition. The entire data provide a homogeneous petrographic classification for the stone findings: carbonate (magnesite) talc schists, also known as soapstones. Among the Alpine <i>pietra ollare</i> lithotype groups (Mannoni et al. 1987), these samples belong to the fine-grained and grey to light-green coloured soapstones, namely the “petrographic group D”, whose quarrying sites in antiquity were commonly recognised in the Valchiavenna area (Central Alps). This <i>pietra ollare</i> provenance of Monte Giove thus reinforces the so-called “Valchiavenna soapstone trade”, from the Mera-Adda-Po Rivers towards the Adriatic harbour of Comacchio, where several <i>pietra ollare</i> findings, dating back between the 7th and 9th centuries, are also well documented. The role played by Comacchio as a Medieval commercial hub for <i>pietra ollare</i> is also discussed in the framework of Monte Giove findings.</p></div>","PeriodicalId":8214,"journal":{"name":"Archaeological and Anthropological Sciences","volume":"17 10","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s12520-025-02315-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256812","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}
Robert J. Lillis, Yingjuan Ma, Shaosui Xu, Justin Deighan, Krishnaprasad Chirakkil, Sonal Jain, Matthew Fillingim, Michael Chaffin, Greg Holsclaw, Scott England, Raghuram Susarla, David Brain, Hoor Al Mazmi, Abigail R. Azari, Yaxue Dong, Nick Schneider, Jared Espley, Shannon Curry
{"title":"IMF Control of Electron Aurora Across Mars' Crustal Magnetic Fields: Insights Into Electron Sources","authors":"Robert J. Lillis, Yingjuan Ma, Shaosui Xu, Justin Deighan, Krishnaprasad Chirakkil, Sonal Jain, Matthew Fillingim, Michael Chaffin, Greg Holsclaw, Scott England, Raghuram Susarla, David Brain, Hoor Al Mazmi, Abigail R. Azari, Yaxue Dong, Nick Schneider, Jared Espley, Shannon Curry","doi":"10.1029/2025JA033913","DOIUrl":"https://doi.org/10.1029/2025JA033913","url":null,"abstract":"<p>We investigate Martian electron aurora utilizing 130.4 nm auroral observations from the Emirates Mars Ultraviolet Spectrograph and IMF clock angle measurements and estimates from MAVEN. Analysis reveals that more than 5 R aurora occurrence in a given region can vary by up to a factor of seven with IMF orientation, generally highest for southward IMF and lowest for westward IMF, with higher auroral occurrence post-dusk, decreasing toward and past midnight before increasing again toward dawn. A broad diversity of IMF and local time dependence of aurora occurrence is observed across Mars' crustal magnetic fields. The polarity of a given crustal field determines whether its field lines preferentially magnetically connect to dayside ionospheric or nightside magnetotail electron sources in the post-dusk or pre-dawn sectors. We thus establish a “source preference metric”, that is, the excess likelihood of aurora when likely magnetically connected to the nightside versus dayside. A wide range of source preferences are observed across the crustal field features, with some showing higher occurrence for night sources, day sources, or neither, often differently when in the post-dusk or pre-dawn sectors. A generally stronger nightside source preference is found for radially inward crustal fields in the predawn sector, and for weaker outward crustal fields in the post-dusk sector. These results highlight the complex and dynamic nature of Mars' magnetic topology in controlling auroral electron access. Future studies integrating in situ electron measurements with synoptic and limb auroral imaging will further constrain the relative contributions of dayside and magnetotail electron populations to Mars' auroral processes.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 10","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145272434","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}
Aeolian ResearchPub Date : 2025-10-11DOI: 10.1016/j.aeolia.2025.101003
Mingyu Wang , Huoqing Li , Yongqiang Liu
{"title":"Estimation of secondary dune density in the hinterland of the Taklimakan Desert","authors":"Mingyu Wang , Huoqing Li , Yongqiang Liu","doi":"10.1016/j.aeolia.2025.101003","DOIUrl":"10.1016/j.aeolia.2025.101003","url":null,"abstract":"<div><div>The secondary dune density is a crucial parameter for studying desert surface characteristics and monitoring the development of sand ridges. It provides an effective means to describe the distribution of regional secondary dunes. However, there is currently no effective method for estimating dune density, particularly for secondary dunes that are attached to large sand ridges, which are often overlooked due to their smaller scale. Therefore, this study presents a more effective method for estimating secondary dune density by utilizing Google Earth images and the YOLOv8s algorithm. This study utilizes Google Earth images from the hinterland of the Taklimakan Desert to construct a secondary dune identification dataset. Based on the dataset, we train and validate the secondary dune identification model to estimate secondary dune density. The research results indicate that the model achieved an average precision (AP50) of 63.58 % for secondary dune identification, outperforming other baseline algorithms. Furthermore, the dune identification model successfully identified a total of 18,208 secondary dunes within the verification area. The model demonstrated a higher predictive capability for secondary dune densities in the Taklimakan Desert hinterland, with a coefficient of determination (<em>R<sup>2</sup></em>) of 0.89 between estimated and observed values. The mean absolute error (<em>MAE</em>) was 20.94 km<sup>−2</sup>, and the root mean square error (<em>RMSE</em>) was 25.04 km<sup>−2</sup>. Crucially, the accuracy of the secondary density estimation is highly dependent on the precise delineation of dune outlines, crest lines, dune arcs, and ridge lines from the imagery. The method for estimating secondary dune density proposed in this study overcomes the limitations of existing research and provides new insights into the evolutionary processes of aeolian dunes.</div></div>","PeriodicalId":49246,"journal":{"name":"Aeolian Research","volume":"74 ","pages":"Article 101003"},"PeriodicalIF":3.4,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264875","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}
Iris T. Stewart, John Dialesandro, Samantha Lei, Lilah Foster
{"title":"Toward the Human Right to Water for Vulnerable Communities: The Effectiveness of Stakeholder Processes to Control Regional Shallow Groundwater Contamination by Nitrates","authors":"Iris T. Stewart, John Dialesandro, Samantha Lei, Lilah Foster","doi":"10.1029/2025wr040896","DOIUrl":"https://doi.org/10.1029/2025wr040896","url":null,"abstract":"Nitrate contamination in shallow drinking water wells is an urgent and persistent concern for agricultural regions and disadvantaged communities worldwide. As viable options for the large‐scale removal of nitrates from groundwater remain elusive, greater emphasis has been placed on stakeholder‐based integrative approaches, yet few have been developed, and fewer evaluated for their effectiveness. The Central Valley in California is one of the most important intensive agricultural regions globally, where such a stakeholder‐based process (CV‐SALTS) has been initiated, and which is poised to serve as a model for controlling nitrate contamination elsewhere. Based on the Groundwater Ambient Monitoring and Assessment Program data for the 2000–2023 period, we develop a new data sufficiency metric, quantify the uncertainties associated with establishing nitrate concentrations and their changes in space and time, the impact of Confined Animal Feeding Operations (CAFOs), seasonal variability and drought on nitrate levels, and how they are addressed through CV‐SALTS policies. Our findings suggest that there remain substantial uncertainties associated with where nitrate concentrations are above safe levels, but that they predominantly intersect with environmental justice communities. Severe drought conditions and the proximity of CAFOS significantly elevated nitrate concentrations, but had previously not been sufficiently monitored or considered. A new data sufficiency metric based on nitrate variability, maximum contaminant level exceedance, and observation density can support stakeholder processes in prioritizing areas for additional monitoring and risk reduction. Our findings form the basis for recommended policy changes that are transferable to other regions.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"102 7 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145260945","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}
Xun Huang , Rongwen Yao , Yunhui Zhang , Xiao Li , Zhongyou Yu , Hongyang Guo
{"title":"Data-driven prediction modeling of groundwater quality using integrated machine learning in Pinggu Basin, China","authors":"Xun Huang , Rongwen Yao , Yunhui Zhang , Xiao Li , Zhongyou Yu , Hongyang Guo","doi":"10.1016/j.ejrh.2025.102812","DOIUrl":"10.1016/j.ejrh.2025.102812","url":null,"abstract":"<div><h3>Study region</h3><div>The Pinggu Basin of Beijing (Capital of China).</div></div><div><h3>Study focus</h3><div>Achieving high-accuracy (>95 %) groundwater quality prediction is key for sustainable groundwater management and protection. This study focused on data-driven prediction modeling — Support Vector Machine (SVM), Random Forest (RF), Back Propagation (BP) Neural Network, and Convolutional Neural Network (CNN) — to predict groundwater quality based on 1019 groundwater samples from the study area. This study provided new insights into model selection and model building for groundwater quality prediction.</div></div><div><h3>New hydrological insights for the region</h3><div>The dissolution of carbonate rocks primarily controlled major hydrochemical ions. More than 90 % of groundwater samples were clean for drinking. Poor-quality samples were distributed in the northwest of the Pinggu Basin in recent years, mainly due to high nitrate levels (>50 mg/L). That nitrate concentration was an important factor controlling the groundwater quality was also concluded from the machine learning (ML) models. The ion ratio diagram revealed that most of the nitrate originated from agricultural nitrogen fertilizer use, with some contribution from urban sewage sources. The BP Neural Network was the most accurate model for predicting nitrate concentration and groundwater quality in the Pinggu Basin (R<sup>2</sup>=0.99, accuracy=0.99).</div></div>","PeriodicalId":48620,"journal":{"name":"Journal of Hydrology-Regional Studies","volume":"62 ","pages":"Article 102812"},"PeriodicalIF":5.0,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268802","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}