Urbanization and climate change impacts on future flood risk in the Pearl River Delta under shared socioeconomic pathways

Xiaoli Chen; Han Zhang; Wenjie Chen; Guoru Huang

doi:10.1016/j.scitotenv.2020.143144

Urbanization and climate change impacts on future flood risk in the Pearl River Delta under shared socioeconomic pathways

Sci Total Environ. 2021 Mar 25:762:143144. doi: 10.1016/j.scitotenv.2020.143144. Epub 2020 Oct 16.

Authors

Xiaoli Chen¹, Han Zhang², Wenjie Chen³, Guoru Huang⁴

Affiliations

¹ School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640, China.
² Guangdong Research Institute of Water Resources and Hydropower, Guangzhou, China.
³ School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640, China; Guangdong Engineering Technology Research Center of Safety and Greenization for Water Conservancy Project, Guangzhou 510640, China. Electronic address: wjchen@scut.edu.cn.
⁴ School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640, China; State Key Laboratory of Subtropical Building Science, South China University of Technology, Guangzhou 510640, China; Guangdong Engineering Technology Research Center of Safety and Greenization for Water Conservancy Project, Guangzhou 510640, China.

PMID: 33127120
DOI: 10.1016/j.scitotenv.2020.143144

Abstract

Climate change and urbanization are converging to challenge the flood control in the Pearl River Delta (PRD) due to their adverse impacts on precipitation extremes and the urban areas environment. Previous studies have investigated temporal changes in flood risk with various single factor, few have considered the joint effects of climate change, urbanization and socio-economic development. Here, based on the representative concentration pathway (RCP) scenarios, we conducted a comprehensive assessment of future (2030-2050) flood risk over the PRD combined with a thorough investigation of climate change, urbanization and socio-economic development. Precipitation extremes were projected using the regional climate model RegCM4.6, and urbanization growth was projected based on the CA-Markov model. The economic and population development was estimated by the shared socio-economic pathways (SSPs). Flood risk mapping with different RCPs-urbanization-SSPs scenarios was developed for the PRD based on the set pair analyze theory. The results show that climate change and urbanization are expected to exacerbate flood risk in most parts of the PRD during the next few decades, concurrently with more intense extreme precipitation events. The high flood risk areas are projected mainly in the urban regions with unfavorable terrain and dense population. The highest flood risk areas are expected to increase by 8.72% and 19.80% under RCP4.5 and RCP8.5 scenarios, respectively. Reducing greenhouse gas emissions may effectively mitigate the flood risk over the PRD. This study highlight the links between flood risk and changing environment, suggesting that flood risk management and preventative actions should be included in regional adaptation strategies.

Keywords: Climate change; Flood risk; Pearl River Delta; SSP scenarios; Set pair analyze; Urbanization.