Integrating Rainfall Return Periods in MCDA-Based Flood Risk Mapping: A Fuzzy-AHP Case Study in an Ungauged Watershed

Integrating Rainfall Return Periods in MCDA-Based Flood Risk Mapping: A Fuzzy-AHP Case Study in an Ungauged Watershed | 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 Integrating Rainfall Return Periods in MCDA-Based Flood Risk Mapping: A Fuzzy-AHP Case Study in an Ungauged Watershed Magfira Syarifuddin, Satoru Oishi, Haryati M. Sengadji, Chris N. Namah, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5926718/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 01 Apr, 2026 Read the published version in Stochastic Environmental Research and Risk Assessment → Version 1 posted 7 You are reading this latest preprint version Abstract Flooding is one of the most devastating hydrological disasters, severely impacting human lives and the environment. Effective flood risk analysis is crucial for mitigation, as it identifies areas at higher risk of flooding. One common approach is to combine Multi-Criteria Decision Analysis (MCDA) with Geographic Information Systems (GIS), which allows decision-makers to map vulnerable areas even when observational data are limited. However, previous studies often neglected the probabilistic nature of extreme events. This study aims to fill the gap by incorporating rainfall return periods into the Fuzzy Analytic Hierarchical Process (Fuzzy AHP), a popular MCDA method, to evaluate its impact on flood risk mapping. The framework considers rainfall scenarios together with key factors that affect flooding. These factors include elevation, slope, river density, distance to rivers, Topographic Wetness Index (TWI), soil type, land use/land cover, population density, female ratio, poverty ratio, and road density. Six rainfall return periods (2, 5, 10, 25, 50, and 100 years) with three distinct intensity-duration patterns are included in the analysis. In total, eighteen rainfall scenarios were generated by combining short-duration–high intensity, moderate-duration–moderate intensity, and long-duration–low intensity events. Including rainfall return periods gave a more balanced view of flood risk factors, with rainfall, elevation, and slope showing the strongest correlations (± 0.7). Validation with Sentinel-1 SAR data showed that by incorporating rainfall return periods into Fuzzy AHP, produced a more robust result. Over 90% of flooded pixels in the Sentinel-1 SAR imagery were correctly classified as the three highest risk classes: Moderate to High, High, and Very High. In contrast, models that did not embed the rainfall return periods misclassified more than 70% of flooded pixels into lower-risk classes. Our findings highlight the importance of considering rainfall return periods for accurate regional flood risk assessment. Flood risks Rainfall return period Fuzzy theorem Analytical Hierarchical Process (AHP) Multi Criteria Decision Analysis (MCDA) Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 01 Apr, 2026 Read the published version in Stochastic Environmental Research and Risk Assessment → Version 1 posted Editorial decision: Revision requested 22 Feb, 2026 Reviewers agreed at journal 03 Oct, 2025 Reviews received at journal 01 Oct, 2025 Reviewers agreed at journal 01 Oct, 2025 Reviewers invited by journal 30 Sep, 2025 Submission checks completed at journal 08 Sep, 2025 First submitted to journal 05 Sep, 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. 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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-5926718","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":527889275,"identity":"48fcdfc6-b261-452d-8fbb-b68e07abff81","order_by":0,"name":"Magfira Syarifuddin","email":"data:image/png;base64,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","orcid":"","institution":"University of Toyama","correspondingAuthor":true,"prefix":"","firstName":"Magfira","middleName":"","lastName":"Syarifuddin","suffix":""},{"id":527889276,"identity":"fbe46ec0-191b-48f5-a2ca-00ad7c15862d","order_by":1,"name":"Satoru Oishi","email":"","orcid":"","institution":"Kobe University","correspondingAuthor":false,"prefix":"","firstName":"Satoru","middleName":"","lastName":"Oishi","suffix":""},{"id":527889277,"identity":"724369c7-b418-4912-8f01-70127219a214","order_by":2,"name":"Haryati M. 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