Accelerating and Widespread Retreat of Global Estuarine Fronts

Accelerating and Widespread Retreat of Global Estuarine Fronts | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Accelerating and Widespread Retreat of Global Estuarine Fronts Fenzhen Su, Dongjie Fu, Hao Yu, Vincent Lyne This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7983543/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Estuarine-fronts retreat poses significant challenges as global environmental changes increasingly shape the frontal dynamics between estuaries and the sea. Prevailing interpretations frequently present inconsistencies, tending to prioritize terrestrial processes while underestimating the increasing impact of sea-level change. Here, we analyze high-resolution data on estuarine fronts positions from 1984 to 2024 across 18 of the world’s largest rivers with discharge higher than 5000 m 3 /s, revealing significant long-term retreat in all cases, with the Amazon exhibiting maximum retreat (102.9 km) and the Indus the least (8.4 km). We also find that most of the rivers posed accelerating retreating trends and six of which are among the top-9 large rivers (Amazon, Orinoco, Yangtze, Paraná, Irrawaddy and Mekong). Our analysis reveals that four major drivers—sea-level, river discharge, sediment flux and wind field—shape these patterns in different ways. Each of these factors singly dominates at least two rivers, accounting altogether for twelve rivers where retreat can be attributed primarily to one driver. In contrast, six rivers exhibit multi-factorial control, with two to three drivers acting jointly. These results demonstrate that estuarine retreat cannot be explained by a universal mechanism; instead, distinct rivers are governed by different combinations of terrestrial and oceanic processes. Oceanic influences, especially sea-level rise, are emerging as pervasive controls and normally with delayed responses. Given projections of sea-level rise of 0.63–1.01 meters by 2100, the accelerating retreat already observed is likely to intensify, with profound implications for biodiversity and ecological balance, highlighting the urgent need for adaptive management strategies. Climate Analysis and Modeling Full Text Additional Declarations The authors declare no competing interests. Supplementary Files SupplementaryMaterialsGlobalEstuaringFrontsRetreat.pdf Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7983543","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":537140390,"identity":"89fc87f2-83a3-46d6-a79f-9db4307c49a7","order_by":0,"name":"Fenzhen 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Prevailing interpretations frequently present inconsistencies, tending to prioritize terrestrial processes while underestimating the increasing impact of sea-level change. Here, we analyze high-resolution data on estuarine fronts positions from 1984 to 2024 across 18 of the world’s largest rivers with discharge higher than 5000 m\u003csup\u003e3\u003c/sup\u003e/s, revealing significant long-term retreat in all cases, with the Amazon exhibiting maximum retreat (102.9 km) and the Indus the least (8.4 km). We also find that most of the rivers posed accelerating retreating trends and six of which are among the top-9 large rivers (Amazon, Orinoco, Yangtze, Paraná, Irrawaddy and Mekong). Our analysis reveals that four major drivers—sea-level, river discharge, sediment flux and wind field—shape these patterns in different ways. Each of these factors singly dominates at least two rivers, accounting altogether for twelve rivers where retreat can be attributed primarily to one driver. In contrast, six rivers exhibit multi-factorial control, with two to three drivers acting jointly. These results demonstrate that estuarine retreat cannot be explained by a universal mechanism; instead, distinct rivers are governed by different combinations of terrestrial and oceanic processes. Oceanic influences, especially sea-level rise, are emerging as pervasive controls and normally with delayed responses. Given projections of sea-level rise of 0.63–1.01 meters by 2100, the accelerating retreat already observed is likely to intensify, with profound implications for biodiversity and ecological balance, highlighting the urgent need for adaptive management strategies.\u003c/p\u003e","manuscriptTitle":"Accelerating and Widespread Retreat of Global Estuarine Fronts","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-31 03:43:48","doi":"10.21203/rs.3.rs-7983543/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"8ea93ec9-6213-4382-bf5a-fd261ba07ce3","owner":[],"postedDate":"October 31st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":57121547,"name":"Climate Analysis and Modeling"}],"tags":[],"updatedAt":"2025-10-31T03:43:49+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-31 03:43:48","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7983543","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7983543","identity":"rs-7983543","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}