The growth mode of built-up land in floodplains and its impacts on flood vulnerability

Yapan Han; Qingxu Huang; Chunyang He; Yongqiang Fang; Jiahong Wen; Jun Gao; Shiqiang Du

doi:10.1016/j.scitotenv.2019.134462

The growth mode of built-up land in floodplains and its impacts on flood vulnerability

Sci Total Environ. 2020 Jan 15:700:134462. doi: 10.1016/j.scitotenv.2019.134462. Epub 2019 Oct 4.

Authors

Yapan Han¹, Qingxu Huang², Chunyang He³, Yongqiang Fang¹, Jiahong Wen⁴, Jun Gao⁵, Shiqiang Du⁶

Affiliations

¹ School of Environmental and Geographical Sciences, Shanghai Normal University, 100 Guilinlu Road, Shanghai 200234, China; Institute of Urban Study, Shanghai Normal University, 100 Guilinlu Road, Shanghai 200234, China.
² State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, 19 Xinjiekouwai Street, Beijing 100875, China. Electronic address: qxhuang@bnu.edu.cn.
³ State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, 19 Xinjiekouwai Street, Beijing 100875, China. Electronic address: hcy@bnu.edu.cn.
⁴ School of Environmental and Geographical Sciences, Shanghai Normal University, 100 Guilinlu Road, Shanghai 200234, China. Electronic address: jhwen@shnu.edu.cn.
⁵ School of Environmental and Geographical Sciences, Shanghai Normal University, 100 Guilinlu Road, Shanghai 200234, China; Institute of Urban Study, Shanghai Normal University, 100 Guilinlu Road, Shanghai 200234, China. Electronic address: gaojun@shnu.edu.cn.
⁶ School of Environmental and Geographical Sciences, Shanghai Normal University, 100 Guilinlu Road, Shanghai 200234, China; Institute of Urban Study, Shanghai Normal University, 100 Guilinlu Road, Shanghai 200234, China; Institute for Environmental Studies, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, The Netherlands. Electronic address: shiqiangdu@shnu.edu.cn.

PMID: 31689649
DOI: 10.1016/j.scitotenv.2019.134462

Abstract

Built-up land in floodplains (BLF) is a vital indicator of the socio-hydrological system, and its dynamics are key to understanding and managing flood risk. However, previous studies have neglected the impacts of BLF growth modes (e.g., patch sizes and expansion types) on flood vulnerability. This paper fills this gap by assessing the BLF's growth modes and revealing their divergent impacts on flood vulnerability using a case study in the Yangtze River Economic Belt (YREB), China. The results show that the BLF has nearly doubled in the YREB during 1990-2014. A considerable proportion (35.43%) of the BLF growth is scattered in small patches (≤1 km²), which have a much stronger correlation with flood occurrence than that of the other patch sizes. In terms of expansion types, the edge-expansion type dominates 57.52% of the BLF growth, followed by the leapfrogging and infilling expansions. Both the leapfrogging and the edge-expanding BLFs are significantly associated with flood occurrence, while the infilling type is not. The patch size and expansion type can thus influence the vulnerability of BLF patches, which is also supported by real-world cases. These findings enrich a general understanding of BLF growth and its impacts on flood vulnerability. The scientific community and policymakers should pay attention to not only the quantity of BLF growth, but also its spatial arrangement.

Keywords: Flood risk management; Nature-based adaptation; Socio-hydrology; Urban planning; Urban sustainability.