A Mechanistic Model for Gas Transfer Velocity in Damodar River

A Mechanistic Model for Gas Transfer Velocity in Damodar River | 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 A Mechanistic Model for Gas Transfer Velocity in Damodar River Jenny Lallawmzuali, Sundararajan Muniyan This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7137521/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 Riverine gas exchange is a critical yet poorly constrained component of global carbon cycling, with traditional models often failing to account for the complex interplay of turbulence, biofilm barriers, and sediment dynamics. Here, we present a mechanistic gas transfer velocity ( \(\:k\) ) model that explicitly integrates: 1. turbulence-driven transfer via shear velocity ( \(\:{u}_{*}\) ), 2. biofilm resistance ( \(\:{R}_{bio}\) ​) as a function of thickness ( \(\:\delta\:\) ) and porosity ( \(\:\varphi\:\) ), 3. sediment clogging ( \(\:{R}_{sed}\) ) scaled to suspended load ( \(\:{C}_{sed}\) ), 4. diurnal photosynthetic adjustments ( \(\:{\varDelta\:k}_{photo}\) ). We apply this model to the Damodar River, India—a regulated, eutrophic system where biofilm proliferation and monsoon-driven sediment pulses create an ideal testbed for evaluating interfacial gas exchange processes. Field measurements (tracer injections, micro-profiling, and Acoustic Doppler Current Profiler, ADCP surveys) reveal that biofilms suppress k by 18–37% in dry-season low-flow reaches ( \(\:\delta\:\) =1.2–2.5 mm), while suspended sediments dominate monsoon fluxes, reducing k by 22–29% at \(\:{C}_{sed}\) >300 mg/L. These findings underscore the necessity of incorporating biofilm-sediment interactions into gas flux models, particularly in anthropogenically altered rivers. Our framework provides a transferable tool for refining carbon budgets and informs management strategies targeting nutrient and sediment loads in river systems. Biofilm Damodar River gas transfer dynamic flow Figures Figure 1 Figure 2 Figure 3 Figure 4 Full Text Additional Declarations No competing interests reported. Tables 1 to 3 are available in the Supplementary Files section. Supplementary Files Tables.pdf figA1.png 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. 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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-7137521","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":501714171,"identity":"dfd50dc3-f248-46d9-b7d6-8704f9c816b5","order_by":0,"name":"Jenny 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River","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"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},"keywords":"Biofilm, Damodar River, gas transfer, dynamic flow","lastPublishedDoi":"10.21203/rs.3.rs-7137521/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7137521/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eRiverine gas exchange is a critical yet poorly constrained component of global carbon cycling, with traditional models often failing to account for the complex interplay of turbulence, biofilm barriers, and sediment dynamics. Here, we present a mechanistic gas transfer velocity (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:k\\)\u003c/span\u003e\u003c/span\u003e) model that explicitly integrates: 1. turbulence-driven transfer via shear velocity (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{u}_{*}\\)\u003c/span\u003e\u003c/span\u003e), 2. biofilm resistance (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{R}_{bio}\\)\u003c/span\u003e\u003c/span\u003e​) as a function of thickness (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\delta\\:\\)\u003c/span\u003e\u003c/span\u003e) and porosity (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\varphi\\:\\)\u003c/span\u003e\u003c/span\u003e), 3. sediment clogging (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{R}_{sed}\\)\u003c/span\u003e\u003c/span\u003e) scaled to suspended load (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{C}_{sed}\\)\u003c/span\u003e\u003c/span\u003e), 4. diurnal photosynthetic adjustments (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varDelta\\:k}_{photo}\\)\u003c/span\u003e\u003c/span\u003e). We apply this model to the Damodar River, India\u0026mdash;a regulated, eutrophic system where biofilm proliferation and monsoon-driven sediment pulses create an ideal testbed for evaluating interfacial gas exchange processes. Field measurements (tracer injections, micro-profiling, and Acoustic Doppler Current Profiler, ADCP surveys) reveal that biofilms suppress \u003cem\u003ek\u003c/em\u003e by 18\u0026ndash;37% in dry-season low-flow reaches (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\delta\\:\\)\u003c/span\u003e\u003c/span\u003e=1.2\u0026ndash;2.5 mm), while suspended sediments dominate monsoon fluxes, reducing \u003cem\u003ek\u003c/em\u003e by 22\u0026ndash;29% at \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{C}_{sed}\\)\u003c/span\u003e\u003c/span\u003e\u0026gt;300 mg/L. These findings underscore the necessity of incorporating biofilm-sediment interactions into gas flux models, particularly in anthropogenically altered rivers. Our framework provides a transferable tool for refining carbon budgets and informs management strategies targeting nutrient and sediment loads in river systems.\u003c/p\u003e","manuscriptTitle":"A Mechanistic Model for Gas Transfer Velocity in Damodar River","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-20 05:31:59","doi":"10.21203/rs.3.rs-7137521/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":"f905ae84-394e-4460-941f-570d23189211","owner":[],"postedDate":"August 20th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-10-22T12:38:35+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-20 05:31:59","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7137521","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7137521","identity":"rs-7137521","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}