Instant water quality index (WQI) prediction via reaeration process and hydraulic parameters in the river system

Instant water quality index (WQI) prediction via reaeration process and hydraulic parameters in the river system | 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 Instant water quality index (WQI) prediction via reaeration process and hydraulic parameters in the river system Amin Arzhangi, Sadegh Partani, Ali Danandeh Mehr, Faeze Ezzati, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7481412/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 28 Jan, 2026 Read the published version in Communications Sustainability → Version 1 posted 10 You are reading this latest preprint version Abstract This study presents a novel approach for predicting the Water Quality Index (WQI) in river systems by integrating reaeration processes and hydraulic parameters. Using a Genetic Programming (GP) model, the reaeration coefficient (K₂) is predicted and used as a predictor for the WQI, significantly improving the accuracy of water quality assessments. The model demonstrates that K₂ can be reliably calculated using only the Froude number (Fr), a dimensionless parameter representing the river's flow hydraulic regime. After several iterations of multivariate linear regressions (MLRs), the less effective parameters (LEPs) were identified and removed, leading to the development of a WQI prediction equation based on Fr while maintaining high prediction accuracy (R² >0.9). Unlike previous studies that utilized multiple predictors, this model relies on the Fr number as a sole hydraulic predictor. Furthermore, a bootstrap-enhanced GP model is introduced, linking K₂ with WQI, with key factors such as Turbidity (Tu), Temperature (T), and K₂ identified as the primary drivers of WQI dynamics. The proposed model is computationally efficient and provides a cost-effective framework for real-time river ecosystem monitoring. The findings suggest that this approach can be applied across different river systems, making it a valuable tool for sustainable water quality management and environmental monitoring. By reducing the reliance on traditional, costly field studies, the model facilitates better decision-making in managing water resources, particularly in regions with limited data. The study paves the way for future research to expand and apply the model to other river systems globally, incorporating seasonal and anthropogenic factors to improve its robustness and predictive accuracy. Earth and environmental sciences/Hydrology Earth and environmental sciences/Environmental sciences/Environmental chemistry/Pollution remediation Earth and environmental sciences/Environmental sciences/Environmental impact Earth and environmental sciences/Environmental social sciences/Sustainability Ecohydrology Environmental Hydraulics Water Quality Index Reaeration Coefficient River Pollution Ecohydraulics Genetic Programming Full Text Additional Declarations There is NO Competing Interest. Supplementary Files supportinginformation.docx Instant water quality index (WQI) prediction via reaeration process and hydraulic parameters in the river system Cite Share Download PDF Status: Published Journal Publication published 28 Jan, 2026 Read the published version in Communications Sustainability → Version 1 posted Editorial decision: revise 05 Nov, 2025 Review # 1 received at journal 29 Sep, 2025 Review # 3 received at journal 25 Sep, 2025 Reviewer # 3 agreed at journal 18 Sep, 2025 Reviewer # 2 agreed at journal 18 Sep, 2025 Reviewer # 1 agreed at journal 18 Sep, 2025 Reviewers invited by journal 18 Sep, 2025 Submission checks completed at journal 08 Sep, 2025 Editor assigned by journal 28 Aug, 2025 First submitted to journal 28 Aug, 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. 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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-7481412","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":512180764,"identity":"cdc3c9c8-2f49-457d-9d52-46b2329ffbff","order_by":0,"name":"Amin Arzhangi","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+0lEQVRIiWNgGAWjYJCCAyDCAEQkVAAJZuYGUrScAWlhJKyFAa6FsQ1M4tfC33468XBBzT17c/azh188nFcbzd8O1PKjYhtOLRJncjccnnGsmNmyJy/NInHb8dwZhxkbGHvO3MbjEaAWHrYENoMDOWYGiduO5TYAtTAztuHWIn/+LVDLvwQeg/NvgFrmHMudT0iLwQ2gLbxtCRIGN3KMHyQ21AC5BLQY3gDawtuXYGBw440ZQ8KxA7kbgVoO4vOL3PnczZ95viXYG5zPMf74o6Yud975wwcf/KjA430kwCbBwHAYzDpAlHogYP7AwFBHrOJRMApGwSgYQQAAopxi8ZoVFO8AAAAASUVORK5CYII=","orcid":"https://orcid.org/0009-0008-9471-7630","institution":"University of Bojnord","correspondingAuthor":true,"prefix":"","firstName":"Amin","middleName":"","lastName":"Arzhangi","suffix":""},{"id":512180765,"identity":"d7bcd35b-1162-416c-ace9-aa82bfa23f2f","order_by":1,"name":"Sadegh Partani","email":"","orcid":"","institution":"University of Bojnord","correspondingAuthor":false,"prefix":"","firstName":"Sadegh","middleName":"","lastName":"Partani","suffix":""},{"id":512180766,"identity":"7b4968b7-1145-4d1d-9947-415530c0e857","order_by":2,"name":"Ali Danandeh Mehr","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Ali","middleName":"Danandeh","lastName":"Mehr","suffix":""},{"id":512180767,"identity":"58f0c281-7373-4c32-a86a-2656b7777196","order_by":3,"name":"Faeze Ezzati","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Faeze","middleName":"","lastName":"Ezzati","suffix":""},{"id":512180768,"identity":"f61078f7-22f7-4205-966d-117273b89a19","order_by":4,"name":"Ali Saber","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Ali","middleName":"","lastName":"Saber","suffix":""}],"badges":[],"createdAt":"2025-08-28 14:52:05","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7481412/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7481412/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s44458-025-00025-3","type":"published","date":"2026-01-28T05:00:00+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":101390635,"identity":"5abdab03-8399-4f50-a688-301a39bcb07f","added_by":"auto","created_at":"2026-01-29 08:23:15","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2205798,"visible":true,"origin":"","legend":"","description":"","filename":"ReaerationK208282025Revisednohighliight.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7481412/v1_covered_1bb4b3c3-7a37-4c09-8571-4d53c15f8c29.pdf"},{"id":91169661,"identity":"5567a312-f152-481e-83a4-319989a6cfbd","added_by":"auto","created_at":"2025-09-12 11:18:54","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":140191,"visible":true,"origin":"","legend":"Instant water quality index (WQI) prediction via reaeration process and hydraulic parameters in the river system","description":"","filename":"supportinginformation.docx","url":"https://assets-eu.researchsquare.com/files/rs-7481412/v1/7df2ce1dfaa0343470a8198e.docx"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Instant water quality index (WQI) prediction via reaeration process and hydraulic parameters in the river system","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"commssustain","isNatureJournal":false,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"commssustain","sideBox":"Learn more about [Communications Sustainability](https://www.nature.com/commssustain/)","snPcode":"44458","submissionUrl":"https://mts-commssustain.nature.com","title":"Communications Sustainability","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Ecohydrology; Environmental Hydraulics; Water Quality Index; Reaeration Coefficient; River Pollution; Ecohydraulics; Genetic Programming","lastPublishedDoi":"10.21203/rs.3.rs-7481412/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7481412/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study presents a novel approach for predicting the Water Quality Index (WQI) in river systems by integrating reaeration processes and hydraulic parameters. Using a Genetic Programming (GP) model, the reaeration coefficient (K₂) is predicted and used as a predictor for the WQI, significantly improving the accuracy of water quality assessments. The model demonstrates that K₂ can be reliably calculated using only the Froude number (Fr), a dimensionless parameter representing the river's flow hydraulic regime. After several iterations of multivariate linear regressions (MLRs), the less effective parameters (LEPs) were identified and removed, leading to the development of a WQI prediction equation based on Fr while maintaining high prediction accuracy (R\u0026sup2; \u0026gt;0.9). Unlike previous studies that utilized multiple predictors, this model relies on the Fr number as a sole hydraulic predictor. Furthermore, a bootstrap-enhanced GP model is introduced, linking K₂ with WQI, with key factors such as Turbidity (Tu), Temperature (T), and K₂ identified as the primary drivers of WQI dynamics. The proposed model is computationally efficient and provides a cost-effective framework for real-time river ecosystem monitoring. The findings suggest that this approach can be applied across different river systems, making it a valuable tool for sustainable water quality management and environmental monitoring. By reducing the reliance on traditional, costly field studies, the model facilitates better decision-making in managing water resources, particularly in regions with limited data. The study paves the way for future research to expand and apply the model to other river systems globally, incorporating seasonal and anthropogenic factors to improve its robustness and predictive accuracy.\u003c/p\u003e","manuscriptTitle":"Instant water quality index (WQI) prediction via reaeration process and hydraulic parameters in the river system","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-12 11:18:49","doi":"10.21203/rs.3.rs-7481412/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"revise","date":"2025-11-05T14:41:39+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"This content is not available.","date":"2025-09-29T04:04:11+00:00","index":1,"fulltext":"This content is not available."},{"type":"editorInvitedReview","content":"This content is not available.","date":"2025-09-25T12:14:56+00:00","index":3,"fulltext":"This content is not available."},{"type":"reviewerAgreed","content":"This content is not available.","date":"2025-09-18T15:39:22+00:00","index":3,"fulltext":"This content is not available."},{"type":"reviewerAgreed","content":"This content is not available.","date":"2025-09-18T15:37:42+00:00","index":2,"fulltext":"This content is not available."},{"type":"reviewerAgreed","content":"This content is not available.","date":"2025-09-18T15:29:06+00:00","index":1,"fulltext":"This content is not available."},{"type":"reviewersInvited","content":"","date":"2025-09-18T15:29:05+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-09T01:09:30+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-28T14:42:43+00:00","index":"","fulltext":""},{"type":"submitted","content":"Communications Sustainability","date":"2025-08-28T14:42:42+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"commssustain","isNatureJournal":false,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"commssustain","sideBox":"Learn more about [Communications Sustainability](https://www.nature.com/commssustain/)","snPcode":"44458","submissionUrl":"https://mts-commssustain.nature.com","title":"Communications Sustainability","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"e4fef0ee-594b-4eeb-9bae-da49a47b3517","owner":[],"postedDate":"September 12th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":54400123,"name":"Earth and environmental sciences/Hydrology"},{"id":54400124,"name":"Earth and environmental sciences/Environmental sciences/Environmental chemistry/Pollution remediation"},{"id":54400125,"name":"Earth and environmental sciences/Environmental sciences/Environmental impact"},{"id":54400126,"name":"Earth and environmental sciences/Environmental social sciences/Sustainability"}],"tags":[],"updatedAt":"2026-01-29T08:23:04+00:00","versionOfRecord":{"articleIdentity":"rs-7481412","link":"https://doi.org/10.1038/s44458-025-00025-3","journal":{"identity":"commssustain","isVorOnly":false,"title":"Communications Sustainability"},"publishedOn":"2026-01-28 05:00:00","publishedOnDateReadable":"January 28th, 2026"},"versionCreatedAt":"2025-09-12 11:18:49","video":"","vorDoi":"10.1038/s44458-025-00025-3","vorDoiUrl":"https://doi.org/10.1038/s44458-025-00025-3","workflowStages":[]},"version":"v1","identity":"rs-7481412","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7481412","identity":"rs-7481412","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}