Journal article
The impact of land subsiding on pluvial flooding in a mega-city: a century of evidence from Shanghai
Geomatics, Natural Hazards and Risk, Vol.17(1), pp.1-19
2026
Abstract
The long-term impact of land subsidence on urban pluvial flooding remains poorly understood, particularly regarding its cumulative effects over century scales. Using Shanghai as a case study, this research investigates the evolution of pluvial flooding driven by subsidence-induced topographic changes from the 1920s to the 2020s. A coupled hydrological-hydrodynamic model (SCS-CN and MIKE 21) was employed to simulate inundation scenarios under multiple rainfall return periods (5- to 200-year events). The results demonstrate that land subsidence significantly alters both the depth and spatial extent of urban flooding, with impacts intensifying under extreme rainfall conditions. The spatial distribution of increased inundation depths aligns closely with historical subsidence patterns. In the 2020s, approximately 5.3% of the study area exhibited high sensitivity, where the ratio of the increase in inundation depth to subsidence magnitude exceeded 10%, with maximum values reaching up to ~290%. By the 1960s, the adverse effects of land subsidence (flood aggravation) had clearly surpassed its mitigating effects (flood reduction), a trend that persists despite recent subsidence control. This study provides valuable insights into the non-linear and lasting relationship between land subsidence and urban flooding, offering critical guidance for flood mitigation and subsidence control strategies in coastal megacities.
Details
- Title
- The impact of land subsiding on pluvial flooding in a mega-city: a century of evidence from Shanghai
- Authors
- Luna Zhao - Shanghai Normal UniversityQing Zhan (Corresponding Author) - Shanghai Institute of Geological SurveyJiahong Wen - Shanghai Normal UniversityChengming Jin - Shanghai Normal UniversityChengcheng Wan - Aerospace Information Research InstituteJianli Liu - University of the Sunshine CoastTongfei Tian - University of the Sunshine CoastHengzhi Hu - Shanghai Business School
- Publication details
- Geomatics, Natural Hazards and Risk, Vol.17(1), pp.1-19
- Publisher
- Taylor & Francis
- Date published
- 2026
- DOI
- 10.1080/19475705.2026.2699011
- ISSN
- 1947-5713
- Copyright note
- © 2026 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The terms on which this article has been published allow the posting of the Accepted Manuscript in a repository by the author(s) or with their consent.
- Data Availability
- The data that support the findings of this study are available from the corresponding author, upon reasonable request.
- Grant note
- This work was supported by the National Natural Science Foundation of China (Grant No. 42171080), Shanghai Philosophy Social Science Planning General Project (Grant No. 2024BJC014), and the Key Laboratory of Land Subsidence Monitoring and Prevention, Ministry of Natural Resources (KLLSMP20230X).
- Organisation Unit
- School of Science, Technology and Engineering
- Language
- English
- Record Identifier
- 991246278102621
- Output Type
- Journal article
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