Long-Term Spatiotemporal Evolution of Annual and Seasonal Aridity Across Saudi Arabia

Long-Term Spatiotemporal Evolution of Annual and Seasonal Aridity Across Saudi Arabia | 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 Long-Term Spatiotemporal Evolution of Annual and Seasonal Aridity Across Saudi Arabia Ali O. Alnahit, Saleh H. Alhathloul This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9238358/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 12 You are reading this latest preprint version Abstract Understanding long-term aridity variability is critical for sustainable water-resource management in arid regions. This study assesses spatiotemporal trends and abrupt regime shifts in the annual and seasonal aridity index (AI) across Saudi Arabia during 1985–2022 using data from a multi-station meteorological network. The AI was calculated as the ratio of precipitation to potential evapotranspiration, with potential evapotranspiration estimated using the Hargreaves-Samani method. Monotonic trends were evaluated using the Mann-Kendall test with Sen’s slope estimation, while structural breaks were identified using both the Pettitt test and cumulative sum (CUSUM) analysis to enhance methodological robustness. The results indicate a general tendency toward increasing aridity at many stations, although the magnitude and statistical significance of trends exhibit clear spatial heterogeneity. Seasonal analyses show that winter and spring display the strongest and most spatially coherent decreases in AI, suggesting that cold-season hydroclimatic variability plays a dominant role in long-term water balance changes, whereas summer and autumn trends are weaker and more dispersed. Both change-point detection methods consistently identify a major hydroclimatic transition clustered around the late 1990s to early 2000s, particularly for the annual, winter, and spring series, confirming the presence of a regionally coherent regime shift. The strong agreement between independent statistical approaches indicates that the detected non-stationarity is robust and not method-dependent. Overall, the findings demonstrate that aridity evolution in Saudi Arabia is characterized by gradual intensification combined with abrupt structural shifts and pronounced seasonal dependence, highlighting the need to incorporate seasonal diagnostics and change-point analysis into long-term drought assessment and water-resource planning in arid environments. Aridity index hydroclimatic trends change-point detection Mann-Kendall test Sen’s slope Saudi Arabia Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 13 May, 2026 Reviews received at journal 11 May, 2026 Reviewers agreed at journal 15 Apr, 2026 Reviews received at journal 14 Apr, 2026 Reviews received at journal 13 Apr, 2026 Reviewers agreed at journal 11 Apr, 2026 Reviewers agreed at journal 10 Apr, 2026 Reviewers agreed at journal 10 Apr, 2026 Reviewers invited by journal 10 Apr, 2026 Editor assigned by journal 26 Mar, 2026 Submission checks completed at journal 26 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. 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-9238358","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":623660075,"identity":"825b023e-de24-493e-89cc-884be70c0111","order_by":0,"name":"Ali O. 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This study assesses spatiotemporal trends and abrupt regime shifts in the annual and seasonal aridity index (AI) across Saudi Arabia during 1985\u0026ndash;2022 using data from a multi-station meteorological network. The AI was calculated as the ratio of precipitation to potential evapotranspiration, with potential evapotranspiration estimated using the Hargreaves-Samani method. Monotonic trends were evaluated using the Mann-Kendall test with Sen\u0026rsquo;s slope estimation, while structural breaks were identified using both the Pettitt test and cumulative sum (CUSUM) analysis to enhance methodological robustness. The results indicate a general tendency toward increasing aridity at many stations, although the magnitude and statistical significance of trends exhibit clear spatial heterogeneity. Seasonal analyses show that winter and spring display the strongest and most spatially coherent decreases in AI, suggesting that cold-season hydroclimatic variability plays a dominant role in long-term water balance changes, whereas summer and autumn trends are weaker and more dispersed. Both change-point detection methods consistently identify a major hydroclimatic transition clustered around the late 1990s to early 2000s, particularly for the annual, winter, and spring series, confirming the presence of a regionally coherent regime shift. The strong agreement between independent statistical approaches indicates that the detected non-stationarity is robust and not method-dependent. Overall, the findings demonstrate that aridity evolution in Saudi Arabia is characterized by gradual intensification combined with abrupt structural shifts and pronounced seasonal dependence, highlighting the need to incorporate seasonal diagnostics and change-point analysis into long-term drought assessment and water-resource planning in arid environments.\u003c/p\u003e","manuscriptTitle":"Long-Term Spatiotemporal Evolution of Annual and Seasonal Aridity Across Saudi Arabia","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-20 07:05:20","doi":"10.21203/rs.3.rs-9238358/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-05-14T01:45:41+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-05-11T11:40:20+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"224821224494890235736079217830441476991","date":"2026-04-15T13:06:15+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-14T17:14:41+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-13T16:45:55+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"305494071312235894167149011267573239417","date":"2026-04-11T11:55:27+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"260849551806955649616248770113715226403","date":"2026-04-10T12:58:30+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"3762424916730691271085143727832414794","date":"2026-04-10T12:56:07+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-10T12:26:01+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-27T03:23:44+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-27T03:23:12+00:00","index":"","fulltext":""},{"type":"submitted","content":"Theoretical and Applied Climatology","date":"2026-03-26T22:43:09+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":"d7a777cd-d6fa-4601-8409-01c195f5aad7","owner":[],"postedDate":"April 20th, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Revision requested","date":"2026-05-14T01:45:41+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-05-11T11:40:20+00:00","index":32,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[],"tags":[],"updatedAt":"2026-05-14T01:53:53+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-20 07:05:20","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9238358","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9238358","identity":"rs-9238358","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}