{"paper_id":"11d5034b-898c-45aa-8bf7-3bf40083c19c","body_text":"Chronic flooding drives cumulative risk in 11,422 urban centres | 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 Chronic flooding drives cumulative risk in 11,422 urban centres Chris Bean, Paul Bates, Becky Collins, Eddie Djemba, Laurence Hawker, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9020274/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract Rapid urbanisation and climate change are increasing flood exposure in cities, but global assessments commonly analyse infrequent, high-magnitude events such as the 1-in-100-year flood. Here, we provide the first global analysis of cumulative chronic flood exposure for 11,422 urban centres. We do this by integrating high-resolution chronic flood hazard data (1-in-5-year flood) with population and gross domestic product (GDP) data and compare the estimated cumulative impacts of these events to the 1-100-year event. Assuming stationarity, we estimate 170 million instances of population exposure to a 1-in-5-year flood, over a hypothetical 100-year period, representing US$1.69 trillion of GDP exposed. Low and lower-middle-income countries experience disproportionate exposure, with the greatest concentrations in small and medium-sized urban centres across poorer regions of Sub-Saharan Africa and East and South-Eastern Asia. In short, those most exposed to cumulative chronic flooding are also those most likely to be adversely impacted. As flood exposure and societal inequality increase, the current ‘big flood’ framing of risk overlooks the insidious consequences of cumulative chronic flood exposure. Cumulative chronic flooding is a globally underappreciated but quantitatively significant source risk for urban dwellers that warrants further research. Earth and environmental sciences/Natural hazards Earth and environmental sciences/Hydrology Earth and environmental sciences/Environmental social sciences/Environmental impact Scientific community and society/Water resources Scientific community and society/Geography Full Text Additional Declarations There is NO Competing Interest. Supplementary Files Supplementarydatatables.xlsx Supplementary Figures 1-7 Supplementaryreport.pdf Supplementary report S1toS7figures.pdf All Supplementary figures Cite Share Download PDF Status: Under Review 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-9020274\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":false,\"archivedVersions\":[],\"articleType\":\"Article\",\"associatedPublications\":[],\"authors\":[{\"id\":608490721,\"identity\":\"2a5f1035-0ac1-46a0-a3a8-98ad77659bac\",\"order_by\":0,\"name\":\"Chris Bean\",\"email\":\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABAElEQVRIie2RMUvDQBTH/+EgXQK3XhDqV3ih0CL1wyhCXCo4ZooHgU7pXunQz+Cia+SBLrrfkKUImXWRgA5ezORwbUaH+3FwvHf34/2PAzye/4gCqt8F8QSQ3Uf9AQ1QwrS7pyAGKOiVaNrXhxS5We0eW9RjuSk/37LrPJcCwXsLnjiH1M/EEZqJql8fkhdiFRcQcQmeuhRSKRjgc22u7mNNlSJbHtnO6T7FBuObrVk0Vsk7RXwdUqoIfEZmEVpFdErYTXEGU8YGi6hJ7kw6SzRxfFsEy5OSLp3Pl+tUfLRZfTw2F81Of+dSjgo2bTZPtMvp4/2pAr3vIz0ej8czgB+OLFH6aJhPGwAAAABJRU5ErkJggg==\",\"orcid\":\"https://orcid.org/0009-0005-6954-4860\",\"institution\":\"Bristol University - School of Geographical Sciences, Bristol, UK\",\"correspondingAuthor\":true,\"prefix\":\"\",\"firstName\":\"Chris\",\"middleName\":\"\",\"lastName\":\"Bean\",\"suffix\":\"\"},{\"id\":608490722,\"identity\":\"27d7f5df-25fe-4351-9d81-7518c1815d8e\",\"order_by\":1,\"name\":\"Paul Bates\",\"email\":\"\",\"orcid\":\"https://orcid.org/0000-0001-9192-9963\",\"institution\":\"Bristol University - School of Geographical Sciences, Bristol, UK; 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