A longitudinal multi‑proxy geospatial classification of peri‑urban transitions across Community Health Units in coastal Kenya

A longitudinal multi‑proxy geospatial classification of peri‑urban transitions across Community Health Units in coastal Kenya | 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 longitudinal multi‑proxy geospatial classification of peri‑urban transitions across Community Health Units in coastal Kenya Prissy Makena, Felix Oluoch, Rosebella Iseme-Ondiek, Fredrick Gudda, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9231692/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 7 You are reading this latest preprint version Abstract Background: Urbanization is spatially heterogeneous in many sub-Saharan African settings. This complicates community health planning when rural and peri-urban labels are applied informally or updated inconsistently. We assessed whether multiple publicly available geospatial proxies could characterize settlement dynamics and support Community Health Unit (CHU) level classification within the Kaloleni Rabai Health and Demographic Surveillance System (KRHDSS) in coastal Kenya. Methods: We conducted a longitudinal ecological analysis across 10 CHUs in Kilifi County with annual observations from 2017 to 2024. Five geospatial proxy indicators of settlement intensity were summarized within CHU boundaries: Visible Infrared Imaging Radiometer Suite (VIIRS) nighttime lights radiance, Sentinel-2 built-up area percentage, WorldPop built-up area percentage, WorldPop population density, and Degree of Urbanization urban percentage. The built-up proxies quantify the extent of built surfaces and do not distinguish construction materials or housing quality. We quantified year-to-year and cumulative percent change, assessed concordance using Pearson correlation coefficients, and derived a consensus classification using k-means clustering applied separately to standardized CHU-level median proxy values, followed by cross-proxy vote scoring. Results: The analytic dataset comprised 80 CHU-year observations per proxy with no missing raw proxy values. Degree of Urbanization showed a pronounced floor effect with 37 zero observations. Median cumulative percent change from 2017 to 2024 was 62.25% for nighttime lights, 110.74% for Sentinel-2 built-up area, 34.14% for WorldPop built-up area, and 14.67% for population density. Sentinel-2 built-up area showed substantial interannual variability, with 41.0% of valid year-to-year transitions negative. Pearson correlation coefficients between pairs of proxy indicators, using pooled raw values across all 80 CHU-year observations, ranged from 0.710 to 0.955. Cross-proxy vote scoring classified 3 of the 10 CHUs as consensus peri-urban. Conclusions: A multi-proxy geospatial approach provides a reproducible complementary framework for delineating CHU settlement contexts in transitional settings. It may support periodic reassessment alongside established administrative classifications where settlement patterns are changing. Divergent proxy patterns, including volatility and floor effects, highlight the value of combining complementary products when distinguishing peri-urban from rural contexts for routine health system planning. urbanization peri-urban geospatial analysis nighttime lights Sentinel-2 WorldPop Degree of Urbanization Community Health Units Kilifi Kenya Full Text Additional Declarations No competing interests reported. Supplementary Files SupplementaryMaterialCHUUrbanization26032026FO.docx Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 04 May, 2026 Reviewers agreed at journal 25 Apr, 2026 Reviewers agreed at journal 17 Apr, 2026 Reviewers invited by journal 15 Apr, 2026 Editor assigned by journal 29 Mar, 2026 Submission checks completed at journal 29 Mar, 2026 First submitted to journal 26 Mar, 2026 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-9231692","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":614183010,"identity":"1873fae3-2b89-47b8-b501-dc6c5b66d2e4","order_by":0,"name":"Prissy Makena","email":"","orcid":"","institution":"Aga Khan University","correspondingAuthor":false,"prefix":"","firstName":"Prissy","middleName":"","lastName":"Makena","suffix":""},{"id":614183011,"identity":"d5293b4d-6e39-4d26-a979-2b791ea0b395","order_by":1,"name":"Felix 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This complicates community health planning when rural and peri-urban labels are applied informally or updated inconsistently. We assessed whether multiple publicly available geospatial proxies could characterize settlement dynamics and support Community Health Unit (CHU) level classification within the Kaloleni Rabai Health and Demographic Surveillance System (KRHDSS) in coastal Kenya.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e We conducted a longitudinal ecological analysis across 10 CHUs in Kilifi County with annual observations from 2017 to 2024. Five geospatial proxy indicators of settlement intensity were summarized within CHU boundaries: Visible Infrared Imaging Radiometer Suite (VIIRS) nighttime lights radiance, Sentinel-2 built-up area percentage, WorldPop built-up area percentage, WorldPop population density, and Degree of Urbanization urban percentage. 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Divergent proxy patterns, including volatility and floor effects, highlight the value of combining complementary products when distinguishing peri-urban from rural contexts for routine health system planning.\u003c/p\u003e","manuscriptTitle":"A longitudinal multi‑proxy geospatial classification of peri‑urban transitions across Community Health Units in coastal Kenya","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-01 08:52:59","doi":"10.21203/rs.3.rs-9231692/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2026-05-04T12:08:36+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"172308057650138153135509042473641582321","date":"2026-04-25T11:24:56+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"232803803303677811266419324502323932875","date":"2026-04-17T10:10:04+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-15T06:10:12+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-30T00:15:46+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-30T00:15:02+00:00","index":"","fulltext":""},{"type":"submitted","content":"International Journal of Health Geographics","date":"2026-03-26T08:47:20+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"international-journal-of-health-geographics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ijhg","sideBox":"Learn more about [International Journal of Health Geographics](http://ij-healthgeographics.biomedcentral.com/)","snPcode":"12942","submissionUrl":"https://submission.nature.com/new-submission/12942/3","title":"International Journal of Health Geographics","twitterHandle":"@IJHGeo","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"4de8d450-95ab-496d-b0b0-42569232db81","owner":[],"postedDate":"April 1st, 2026","published":true,"recentEditorialEvents":[{"type":"editorInvitedReview","content":"","date":"2026-05-04T12:08:36+00:00","index":19,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-15T06:23:21+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-01 08:52:59","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9231692","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9231692","identity":"rs-9231692","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}