Future sea level rise exacerbates compound floods induced by rainstorm and storm tide during super typhoon events: A case study from Zhuhai, China

Zhaoyang Zeng; Chengguang Lai; Zhaoli Wang; Yuhong Chen; Xiaohong Chen

doi:10.1016/j.scitotenv.2023.168799

Future sea level rise exacerbates compound floods induced by rainstorm and storm tide during super typhoon events: A case study from Zhuhai, China

Sci Total Environ. 2024 Feb 10:911:168799. doi: 10.1016/j.scitotenv.2023.168799. Epub 2023 Nov 22.

Authors

Zhaoyang Zeng¹, Chengguang Lai², Zhaoli Wang³, Yuhong Chen¹, Xiaohong Chen⁴

Affiliations

¹ School of Civil Engineering and Transportation, State Key Laboratory of Subtropical Building and Urban Science, South China University of Technology, Guangzhou 510641, China.
² School of Civil Engineering and Transportation, State Key Laboratory of Subtropical Building and Urban Science, South China University of Technology, Guangzhou 510641, China; Pazhou Lab, Guangzhou 510335, China.
³ School of Civil Engineering and Transportation, State Key Laboratory of Subtropical Building and Urban Science, South China University of Technology, Guangzhou 510641, China; Pazhou Lab, Guangzhou 510335, China. Electronic address: wangzhl@scut.edu.cn.
⁴ Center for Water Resources and Environment, Sun Yat-sen University, Guangzhou 510275, China.

PMID: 37996036
DOI: 10.1016/j.scitotenv.2023.168799

Abstract

Compound floods are becoming a growing threat in coastal cities against a background of global sea level rise (SLR), and may cause increasing impacts on societal safety and economy. How to quantify the impact of SLR and compound effects among various flood causes on compound flood have become important challenges. We propose a modeling framework which integrates atmospheric, storm tide and urban flood (IASTUF) models to characterize the various physical processes related to compound flood. Future SLR projections under various shared socioeconomic and respective concentration pathway emission scenarios are considered. Hengqin Island (Zhuhai City, China) frequently experiences typhoon conditions combined with rainstorm and storm surge events. Its population has increased more than sixfold during the past decade, stimulating urgent demands for assessments of the potential risks associated with future compound floods in the context of potential SLR. A compound flood event in northern Hengqin Island, caused by the super typhoon Mangkhut in 2018, is selected as a case study to verify the proposed modeling framework. Results show that the IASTUF modeling framework can capture well the combined processes of typhoon, rainstorm, storm tide and inland flooding and demonstrates good performance in quantifying compound flood magnitudes. Compared to the current scenario, the node flooding volume (from the drainage system) and the maximum inundation area (with inundation depths >1 m) in 2050 are projected to increase by 20-26 % and 41-85 %, respectively, and these increases rise to 46-84 % and 23-71 times by 2100. The inundation volumes and water depths due to compound events are larger than the sum of those caused by the corresponding single-cause events, indicating that concurrent rainstorm and storm surge induce positive compound effects on flood magnitude. These findings can provide guidance for the management and mitigation of future compound flood hazards driven by super typhoon events.

Keywords: Compound effect; Compound flood; Future inundation changes; Modeling framework; Sea level rise.