Rainwater Composition of a Sub-tropical Urban Indian Town Under the Influence of Natural and Anthropogenic Factors

Rainwater Composition of a Sub-tropical Urban Indian Town Under the Influence of Natural and Anthropogenic Factors | 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 Rainwater Composition of a Sub-tropical Urban Indian Town Under the Influence of Natural and Anthropogenic Factors Rajesh Kumar Vishwakarma, Himanshu Joshi, Ashantha Goonetilleke This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7174332/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 07 Feb, 2026 Read the published version in Theoretical and Applied Climatology → Version 1 posted 13 You are reading this latest preprint version Abstract Rainwater quality studies were conducted during July to September of 2016–2019 at a sub-tropical urban location in north India, viz. Roorkee (29.8543° N, 77.8880° E). The parameters pH, electrical conductivity, and major chemical constituents were measured for the precipitation samples. The volume-weighted mean electrical conductivity values were in the range 21.57 ± 1.63, and the pH values indicated the precipitation events to be mostly alkaline. The ionic concentration in the study area followed the order of: \(\:{Ca}^{2+}>HC{O}_{3}^{-}>C{l}^{-}>{Na}^{+}>N{O}_{3}^{-}>S{O}_{4}^{2-}>{Mg}^{2+}>{K}^{+}\) . The dominant ions observed alongwith their weighted mean concentration values were as Ca 2+ (115.19 ± 96 µeq/l), HCO 3 − (90.95 ± 64 µeq/l), Cl − (58.30 ± 38 µeq/l), Na + (38.42 ± 22 µeq/l), and NO 3 − (36.22 ± 23 µeq/l). Aggregates of the acidic species \(\:\left(S{O}_{4}^{2-}+{NO}_{3}^{-}\right)\) and the major cations \(\:\left({Ca}^{2+}+{Mg}^{2+}\right)\) respectively showed a substantial correlation (r = 0.83; P < 0.001), highlighting that the presence of alkaline species in the rainwater could act as acidity neutralizing agents. The presence of sulphates in water was assessed to the order of 85%, whereas nitrate presence was around 15%. Both of these were apparently contributed through anthropogenic activities, driven by combustion of fossil fuel or biomass etc. Principal Component Analysis (PCA) was employed to transform the original variables into a new set of uncorrelated principal components, and to effectively reduce the dimensionality of the dataset while still capturing the majority of the variability in Rainwater quality. The resulting principal components (P1 to P4) pointed towards key factors influencing water quality. For assessing the temporal variability in the rainwater quality during different phases of the monsoon season over a period of few years, the ANOVA-derived hypotheses were applied. Backward trajectory analysis was applied as a tool for investigating the transport and origin of air pollutants. Using a combination of meteorological data and trajectory analysis tools, the study evaluated the potential of each site for capturing regional and long-range transport of pollutants. Rainwater ionic species chemical composition alkalinity backward trajectory analysis sea salt fraction Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 07 Feb, 2026 Read the published version in Theoretical and Applied Climatology → Version 1 posted Editorial decision: Revision requested 13 Oct, 2025 Reviews received at journal 12 Oct, 2025 Reviews received at journal 09 Oct, 2025 Reviewers agreed at journal 29 Sep, 2025 Reviewers agreed at journal 28 Sep, 2025 Reviewers agreed at journal 27 Sep, 2025 Reviewers agreed at journal 27 Sep, 2025 Reviewers agreed at journal 07 Aug, 2025 Reviewers agreed at journal 07 Aug, 2025 Reviewers invited by journal 07 Aug, 2025 Editor assigned by journal 23 Jul, 2025 Submission checks completed at journal 23 Jul, 2025 First submitted to journal 21 Jul, 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. 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-7174332","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":497960310,"identity":"b27511f4-81db-44c1-867b-ee4fa8e7eb8b","order_by":0,"name":"Rajesh Kumar Vishwakarma","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABB0lEQVRIiWNgGAWjYFACxgZmIGkAZn9sYGBgY4ZKsBGjhXEmWAszIS0MDHAtzLwNMD4eYD4juflzYZudMf/s04mfbXccZuBj5z/2gaHGjoFPugGrFpkbiW3SM9uSzSTO5W6Wzj1zGOQw5hkMx5IZ2GQOYNUiwXOwjZl3G7MNwxneDdK5bRAtQI8cYGCTSMClpfkz77Z6G/kzvJt/W8K1/MOjhb2xQZp322EzgzO826QZYVoY2/BqaZPm/Xfc2BCoxbK3LZ0HqMWYIbEvmQenFmb2x595zlQbzgM67MbPNms5+f6Djxk+fLOTk5+BXQs6aOYBU0DFPESpB4I6YhWOglEwCkbBCAIAK71M2KwwGtgAAAAASUVORK5CYII=","orcid":"","institution":"Indian Institute of Technology Roorkee","correspondingAuthor":true,"prefix":"","firstName":"Rajesh","middleName":"Kumar","lastName":"Vishwakarma","suffix":""},{"id":497960312,"identity":"4f9bd736-95b2-4597-ab28-85de89faeca0","order_by":1,"name":"Himanshu Joshi","email":"","orcid":"","institution":"Indian Institute of Technology Roorkee","correspondingAuthor":false,"prefix":"","firstName":"Himanshu","middleName":"","lastName":"Joshi","suffix":""},{"id":497960315,"identity":"aba0ef1d-ea72-4098-b93f-3befec24acbe","order_by":2,"name":"Ashantha Goonetilleke","email":"","orcid":"","institution":"Queensland University of Technology","correspondingAuthor":false,"prefix":"","firstName":"Ashantha","middleName":"","lastName":"Goonetilleke","suffix":""}],"badges":[],"createdAt":"2025-07-21 07:23:19","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7174332/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7174332/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00704-026-06038-9","type":"published","date":"2026-02-07T15:57:48+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":102234257,"identity":"9f39589b-74a7-4583-8813-3674baec719f","added_by":"auto","created_at":"2026-02-09 16:08:36","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":895717,"visible":true,"origin":"","legend":"","description":"","filename":"Manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7174332/v1_covered_233a9cdc-69d2-41d9-b2c8-a1985dc1739b.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eRainwater Composition of a Sub-tropical Urban Indian Town Under the Influence of Natural and Anthropogenic Factors\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"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":"theoretical-and-applied-climatology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"taac","sideBox":"Learn more about [Theoretical and Applied Climatology](https://www.springer.com/journal/704)","snPcode":"704","submissionUrl":"https://submission.nature.com/new-submission/704/3","title":"Theoretical and Applied Climatology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Rainwater, ionic species, chemical composition, alkalinity, backward trajectory analysis, sea salt fraction","lastPublishedDoi":"10.21203/rs.3.rs-7174332/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7174332/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eRainwater quality studies were conducted during July to September of 2016\u0026ndash;2019 at a sub-tropical urban location in north India, viz. Roorkee (29.8543\u0026deg; N, 77.8880\u0026deg; E). The parameters pH, electrical conductivity, and major chemical constituents were measured for the precipitation samples. The volume-weighted mean electrical conductivity values were in the range 21.57\u0026thinsp;\u0026plusmn;\u0026thinsp;1.63, and the pH values indicated the precipitation events to be mostly alkaline. The ionic concentration in the study area followed the order of: \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{Ca}^{2+}\u0026gt;HC{O}_{3}^{-}\u0026gt;C{l}^{-}\u0026gt;{Na}^{+}\u0026gt;N{O}_{3}^{-}\u0026gt;S{O}_{4}^{2-}\u0026gt;{Mg}^{2+}\u0026gt;{K}^{+}\\)\u003c/span\u003e\u003c/span\u003e. The dominant ions observed alongwith their weighted mean concentration values were as Ca\u003csup\u003e2+\u003c/sup\u003e (115.19\u0026thinsp;\u0026plusmn;\u0026thinsp;96 \u0026micro;eq/l), HCO\u003csub\u003e3\u003c/sub\u003e\u003csup\u003e\u0026minus;\u003c/sup\u003e (90.95\u0026thinsp;\u0026plusmn;\u0026thinsp;64 \u0026micro;eq/l), Cl\u003csup\u003e\u0026minus;\u003c/sup\u003e (58.30\u0026thinsp;\u0026plusmn;\u0026thinsp;38 \u0026micro;eq/l), Na\u003csup\u003e+\u003c/sup\u003e (38.42\u0026thinsp;\u0026plusmn;\u0026thinsp;22 \u0026micro;eq/l), and NO\u003csub\u003e3\u003c/sub\u003e\u003csup\u003e\u0026minus;\u003c/sup\u003e (36.22\u0026thinsp;\u0026plusmn;\u0026thinsp;23 \u0026micro;eq/l). Aggregates of the acidic species \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\left(S{O}_{4}^{2-}+{NO}_{3}^{-}\\right)\\)\u003c/span\u003e\u003c/span\u003e and the major cations \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\left({Ca}^{2+}+{Mg}^{2+}\\right)\\)\u003c/span\u003e\u003c/span\u003e respectively showed a substantial correlation (r\u0026thinsp;=\u0026thinsp;0.83; P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), highlighting that the presence of alkaline species in the rainwater could act as acidity neutralizing agents. The presence of sulphates in water was assessed to the order of 85%, whereas nitrate presence was around 15%. Both of these were apparently contributed through anthropogenic activities, driven by combustion of fossil fuel or biomass etc. Principal Component Analysis (PCA) was employed to transform the original variables into a new set of uncorrelated principal components, and to effectively reduce the dimensionality of the dataset while still capturing the majority of the variability in Rainwater quality. The resulting principal components (P1 to P4) pointed towards key factors influencing water quality. For assessing the temporal variability in the rainwater quality during different phases of the monsoon season over a period of few years, the ANOVA-derived hypotheses were applied. Backward trajectory analysis was applied as a tool for investigating the transport and origin of air pollutants. Using a combination of meteorological data and trajectory analysis tools, the study evaluated the potential of each site for capturing regional and long-range transport of pollutants.\u003c/p\u003e","manuscriptTitle":"Rainwater Composition of a Sub-tropical Urban Indian Town Under the Influence of Natural and Anthropogenic Factors","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-12 11:42:57","doi":"10.21203/rs.3.rs-7174332/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-10-13T06:46:24+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-12T19:44:27+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-09T06:25:11+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"97464865359859635456506711563063678685","date":"2025-09-29T12:01:58+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"135404060011632978561109340046776618097","date":"2025-09-28T05:12:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"280033078029677910785887670181729753751","date":"2025-09-27T12:02:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"45521826654128595028745836250243631499","date":"2025-09-27T12:02:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"42124674206938475750682196819670587490","date":"2025-08-07T17:28:55+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"54596812768423451326976421042493354963","date":"2025-08-07T06:30:45+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-08-07T05:24:46+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-07-23T23:02:55+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-07-23T23:02:17+00:00","index":"","fulltext":""},{"type":"submitted","content":"Theoretical and Applied Climatology","date":"2025-07-21T07:14:02+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"theoretical-and-applied-climatology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"taac","sideBox":"Learn more about [Theoretical and Applied Climatology](https://www.springer.com/journal/704)","snPcode":"704","submissionUrl":"https://submission.nature.com/new-submission/704/3","title":"Theoretical and Applied Climatology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"06c29939-cd1e-4a55-b68b-5b8f68cb1588","owner":[],"postedDate":"August 12th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-02-09T16:04:22+00:00","versionOfRecord":{"articleIdentity":"rs-7174332","link":"https://doi.org/10.1007/s00704-026-06038-9","journal":{"identity":"theoretical-and-applied-climatology","isVorOnly":false,"title":"Theoretical and Applied Climatology"},"publishedOn":"2026-02-07 15:57:48","publishedOnDateReadable":"February 7th, 2026"},"versionCreatedAt":"2025-08-12 11:42:57","video":"","vorDoi":"10.1007/s00704-026-06038-9","vorDoiUrl":"https://doi.org/10.1007/s00704-026-06038-9","workflowStages":[]},"version":"v1","identity":"rs-7174332","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7174332","identity":"rs-7174332","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}