Unsustainable groundwater-fed irrigation drives deltaic water scarcity and compound flooding

Unsustainable groundwater-fed irrigation drives deltaic water scarcity and compound flooding | 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 Unsustainable groundwater-fed irrigation drives deltaic water scarcity and compound flooding Augusto Getirana, Nishan Kumar Biswas, Sujay kumar, Wanshu Nie, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4355431/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 16 May, 2025 Read the published version in Nature Sustainability → Version 1 posted You are reading this latest preprint version Abstract Southern Asia benefits from groundwater pumping for dry-season irrigation by increasing both crop productivity and monsoon aquifer recharge rates in the region. Based on a data-driven integrated modeling system, we provide numerical evidence that the impacts of unsustainable groundwater-fed irrigation surface freshwater availability go beyond what was previously understood. Our results confirm findings from previous studies that increased groundwater recharge rates during wet seasons over 2002-2021, but they are insufficient for aquifers to recover, gradually depleting groundwater across the Ganges-Brahmaputra-Meghna delta. Main findings are that such an increased recharge causes a drop in runoff generation during the monsoons, resulting in lower flood risk, a good outcome, but also less surface freshwater available for farming, which may trigger additional groundwater demand during monsoons. Drop in coastal flooding induced by groundwater-fed irrigation exceeds by ~5-10 fold the flooding increase caused by sea level rise. Reduced runoff also increases seawater intrusion, driven by less freshwater to push ocean water away. This is particularly concerning, since the region has been under rising sea levels and sinking lands. These findings over this delta have global implications, as humans and climate are increasingly pressuring coastal and deltaic ecosystems worldwide. Earth and environmental sciences/Hydrology Earth and environmental sciences/Environmental sciences/Environmental impact Earth and environmental sciences/Natural hazards Scientific community and society/Water resources Scientific community and society/Agriculture Full Text Additional Declarations There is NO Competing Interest. Cite Share Download PDF Status: Published Journal Publication published 16 May, 2025 Read the published version in Nature Sustainability → 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. 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-4355431","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":302783459,"identity":"38a99b45-3cd6-4811-96fb-9c40371963bc","order_by":0,"name":"Augusto Getirana","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABFklEQVRIiWNgGAWjYLCDAyCCnzi1CSCCGaJFsoEULWBgcICAYv4Z6dckf/6wYZB37z94uKLmjrzx7ebHH34w1Mrh0itxI6dMmichjcHwzGGGg2eOPTPcdueYmWQPw3FjnNbdyEmTZkg4zGA4I5nhYAPbYcZtNxLMGHgYjiXOxOEpeaAWyR8gLfMfA7X8O2y/eUb6549/8GgxuJF+TIIHqEVegpnhYGPb4cQNEjkG0jwMNYn9ONxleOYNszVPWhqPAU+ywcHGvsPJM0C+kzE4YIwrguSOpz+8+cPGRk6+/eDjjw3fDtv2z0jf/PFNRZ0cGw4tDAw8BhDyAKqDD+PUwMDA/gBMyTegCtfh0TIKRsEoGAUjDAAAxFthgKPEQ6oAAAAASUVORK5CYII=","orcid":"https://orcid.org/0000-0001-9635-7220","institution":"NASA Goddard Space Flight Center","correspondingAuthor":true,"prefix":"","firstName":"Augusto","middleName":"","lastName":"Getirana","suffix":""},{"id":302783460,"identity":"4f491ae3-3c15-4b93-9d5c-dee8cd171a07","order_by":1,"name":"Nishan Kumar Biswas","email":"","orcid":"","institution":"NASA Goddard Space Flight Center","correspondingAuthor":false,"prefix":"","firstName":"Nishan","middleName":"Kumar","lastName":"Biswas","suffix":""},{"id":302783461,"identity":"77affdeb-5f56-4666-8090-112f91d5f82e","order_by":2,"name":"Sujay kumar","email":"","orcid":"https://orcid.org/0000-0001-8797-9482","institution":"NASA GSFC","correspondingAuthor":false,"prefix":"","firstName":"Sujay","middleName":"","lastName":"kumar","suffix":""},{"id":302783462,"identity":"605f2afc-e504-42b6-9f48-38481f25ef8f","order_by":3,"name":"Wanshu Nie","email":"","orcid":"https://orcid.org/0000-0003-3639-9570","institution":"Johns Hopkins University","correspondingAuthor":false,"prefix":"","firstName":"Wanshu","middleName":"","lastName":"Nie","suffix":""},{"id":302783463,"identity":"e9d6fa34-cd0d-4e52-a218-8dba36ec66ad","order_by":4,"name":"Shahryar Ahmad","email":"","orcid":"https://orcid.org/0000-0002-9789-3137","institution":"NASA Goddard Space Flight Center","correspondingAuthor":false,"prefix":"","firstName":"Shahryar","middleName":"","lastName":"Ahmad","suffix":""},{"id":302783464,"identity":"dc5a09cf-2492-4390-9f70-7c212589110f","order_by":5,"name":"Fadji Zaouna Maina","email":"","orcid":"https://orcid.org/0000-0003-3126-4343","institution":"NASA Goddard Space Flight Center","correspondingAuthor":false,"prefix":"","firstName":"Fadji","middleName":"Zaouna","lastName":"Maina","suffix":""},{"id":302783465,"identity":"6376e737-aa09-490a-9715-79514012f46a","order_by":6,"name":"Nazmus Sakib","email":"","orcid":"","institution":"Bangladesh Water Development Board","correspondingAuthor":false,"prefix":"","firstName":"Nazmus","middleName":"","lastName":"Sakib","suffix":""},{"id":302783466,"identity":"a7cc9bc0-6ce9-457e-9be4-48297b8fd463","order_by":7,"name":"Md Sazzad Hossain","email":"","orcid":"","institution":"Bangladesh Water Development Board","correspondingAuthor":false,"prefix":"","firstName":"Md","middleName":"Sazzad","lastName":"Hossain","suffix":""},{"id":302783467,"identity":"75283946-45d8-4a6e-9893-36536a629889","order_by":8,"name":"Robin Kumar Biswas","email":"","orcid":"","institution":"Bangladesh Water Development Board","correspondingAuthor":false,"prefix":"","firstName":"Robin","middleName":"Kumar","lastName":"Biswas","suffix":""}],"badges":[],"createdAt":"2024-05-01 17:35:49","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4355431/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4355431/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41893-025-01566-0","type":"published","date":"2025-05-16T04:00:00+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":82941421,"identity":"98f4d98f-1bf0-4752-a9d5-02529cd60619","added_by":"auto","created_at":"2025-05-17 07:06:02","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2764095,"visible":true,"origin":"","legend":"","description":"","filename":"getiranaetalv2combined.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4355431/v1_covered_4775f51e-b12c-4b11-8065-e2c3a3387477.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Unsustainable groundwater-fed irrigation drives deltaic water scarcity and compound flooding","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":"nature-portfolio","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Nature Portfolio","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"ejp","reportingPortfolio":"","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-4355431/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4355431/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Southern Asia benefits from groundwater pumping for dry-season irrigation by increasing both crop productivity and monsoon aquifer recharge rates in the region. Based on a data-driven integrated modeling system, we provide numerical evidence that the impacts of unsustainable groundwater-fed irrigation surface freshwater availability go beyond what was previously understood. Our results confirm findings from previous studies that increased groundwater recharge rates during wet seasons over 2002-2021, but they are insufficient for aquifers to recover, gradually depleting groundwater across the Ganges-Brahmaputra-Meghna delta. Main findings are that such an increased recharge causes a drop in runoff generation during the monsoons, resulting in lower flood risk, a good outcome, but also less surface freshwater available for farming, which may trigger additional groundwater demand during monsoons. Drop in coastal flooding induced by groundwater-fed irrigation exceeds by ~5-10 fold the flooding increase caused by sea level rise. Reduced runoff also increases seawater intrusion, driven by less freshwater to push ocean water away. This is particularly concerning, since the region has been under rising sea levels and sinking lands. These findings over this delta have global implications, as humans and climate are increasingly pressuring coastal and deltaic ecosystems worldwide. ","manuscriptTitle":"Unsustainable groundwater-fed irrigation drives deltaic water scarcity and compound flooding","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-05-16 03:03:09","doi":"10.21203/rs.3.rs-4355431/v1","editorialEvents":[],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"nature-sustainability","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"natsustain","sideBox":"Learn more about [Nature Sustainability](http://www.nature.com/natsustain/)","snPcode":"","submissionUrl":"","title":"Nature Sustainability","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature Research","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"4111b04e-f50d-4048-bb16-8dbd8ce78314","owner":[],"postedDate":"May 16th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":31950988,"name":"Earth and environmental sciences/Hydrology"},{"id":31950989,"name":"Earth and environmental sciences/Environmental sciences/Environmental impact"},{"id":31950990,"name":"Earth and environmental sciences/Natural hazards"},{"id":31950991,"name":"Scientific community and society/Water resources"},{"id":31950992,"name":"Scientific community and society/Agriculture"}],"tags":[],"updatedAt":"2025-05-17T07:05:55+00:00","versionOfRecord":{"articleIdentity":"rs-4355431","link":"https://doi.org/10.1038/s41893-025-01566-0","journal":{"identity":"nature-sustainability","isVorOnly":false,"title":"Nature Sustainability"},"publishedOn":"2025-05-16 04:00:00","publishedOnDateReadable":"May 16th, 2025"},"versionCreatedAt":"2024-05-16 03:03:09","video":"","vorDoi":"10.1038/s41893-025-01566-0","vorDoiUrl":"https://doi.org/10.1038/s41893-025-01566-0","workflowStages":[]},"version":"v1","identity":"rs-4355431","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4355431","identity":"rs-4355431","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}