Modeling Microplastic Transport in Watershed and Estuarine Systems: A Coupled DHSVM-FVCOM Approach

Modeling Microplastic Transport in Watershed and Estuarine Systems: A Coupled DHSVM-FVCOM Approach | 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 Article Modeling Microplastic Transport in Watershed and Estuarine Systems: A Coupled DHSVM-FVCOM Approach Zhuoran Duan, Yicheng Huang, Mark Wigmosta, Zhi Li, Ning Sun, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8444276/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 10 You are reading this latest preprint version Abstract Microplastics (MPs) are an emerging environmental concern owing to their widespread presence and ecological impacts. We develop a coupled watershed–estuary modeling framework to simulate MP transport from terrestrial sources to estuarine systems. The Distributed Hydrology Soil Vegetation Model (DHSVM) is enhanced to represent point and nonpoint MP sources and is coupled with the Finite Volume Community Ocean Model (FVCOM) to capture estuarine transport. Applied to the Delaware River Basin, the framework simulates MP buildup and wash-off, including airborne deposition and wastewater treatment plant (WWTP) discharges. Coupling the estuary model substantially alters MP discharge to the ocean, highlighting retention within Delaware Bay from salinity-induced circulation. MP retention on land is strongly influenced by watershed topography, urban distribution, and source configuration, with the “Lower Delaware” subwatershed exhibiting minimal residence time. These results demonstrate the importance of watershed–estuary coupling for accurate MP export estimates and provide a framework for evaluating MP fate in aquatic environments. Biological sciences/Ecology Earth and environmental sciences/Ecology Earth and environmental sciences/Environmental sciences Earth and environmental sciences/Hydrology Full Text Additional Declarations No competing interests reported. Supplementary Files Supplementary.pdf Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 12 Mar, 2026 Reviews received at journal 19 Feb, 2026 Reviewers agreed at journal 02 Feb, 2026 Reviews received at journal 11 Jan, 2026 Reviewers agreed at journal 02 Jan, 2026 Reviewers invited by journal 02 Jan, 2026 Editor invited by journal 31 Dec, 2025 Editor assigned by journal 27 Dec, 2025 Submission checks completed at journal 27 Dec, 2025 First submitted to journal 24 Dec, 2025 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. 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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-8444276","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":568495293,"identity":"62b6b357-7bf4-481c-bd05-5f50a919fe4a","order_by":0,"name":"Zhuoran Duan","email":"","orcid":"","institution":"Pacific Northwest National Laboratory","correspondingAuthor":false,"prefix":"","firstName":"Zhuoran","middleName":"","lastName":"Duan","suffix":""},{"id":568495294,"identity":"3d45f29b-4386-4927-906a-8791e01f64fc","order_by":1,"name":"Yicheng Huang","email":"","orcid":"","institution":"Pacific Northwest National 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