Risk assessment of shanghai extreme flooding under the land use change scenario

Xinmeng Shan,Jun Wang,Jie Yin

doi:10.1007/s11069-021-04978-1

Abstract

Environmental changes have led to non-stationary flood risks in coastal cities. How to quantitatively characterize the future change trend and effectively adapt is a critical problem that needs urgent attention. To this end, this study uses the 2010 Shanghai land use data as the base and utilizes the future land use simulation (FLUS) model to simulate future land use change scenarios (2030, 2050, and 2100). Based on the results of storm and flood numerical simulations, probabilistic risk, and other multidisciplinary methods, extreme storm and flood risks of various land uses (residential, commercial and public service, industrial, transportation, agricultural, and other land) in Shanghai are analyzed. Our findings demonstrate that the future land use simulated results show that the simulation accuracy is very high, meeting the needs of our research. We evaluated future land use exposure assets and losses and found that their spatial distribution patterns are consistent, ranging from a sporadic distribution for 1/10-year to a banded distribution for 1/1000-year under the two emission scenarios. In terms of economic loss, the losses of total land use in Shanghai for 1/1000-year in 2100 are 1.8–2.7 times that of 2010 under the RCP8.5 scenario. The expected annual damage (EAD) of Shanghai’s land use in 2030, 2050, and 2100 is 189.9 million CNY, 409.8 million CNY, and 743.5 million CNY under the RCP8.5 scenario, respectively, which is 1.7–3.0 times the EAD under the RCP2.6 scenario. Among them, residential, commercial and public service land as well as industrial land has the highest EAD. Risks are mainly distributed in the city center, the lower reaches of the Huangpu River, the northern shore of Hangzhou Bay, the Qingpu (QP)–Songjiang (SJ) depression in the southwest, and Chongming (CM) Island (southwest and northeast). Our work can provide meaningful information for risk-sensitive urban planning and resilience building in Shanghai. These multidisciplinary methods can also be applied to assess flood risk in other coastal cities.

Highlights

Many coastal cities around the world face huge risks of extreme storm floods (Najafi et al 2021; Wolff et al 2020; Oppenheimer et al 2019; Shen et al 2019; Chan et al 2018; Nicholls et al 2014)
There is an urgent need to understand the spatio-temporal dynamics and future trends of flood risk under environmental change scenarios to ensure the sustainable development of coastal cities (Shan et al 2021; Du et al 2020; Jongman et al 2018; Hinkel et al 2018)
Some scholars have carried out research on the dynamic changes of flood risk in coastal cities under the background of sea level rise, land subsidence, and climate change

Summary

Introduction

Many coastal cities around the world face huge risks of extreme storm floods (Najafi et al 2021; Wolff et al 2020; Oppenheimer et al 2019; Shen et al 2019; Chan et al 2018; Nicholls et al 2014). Several researches have focused on the impact of coastal flooding on people and assets under the scenario of sea level rise for New York (Garner et al 2017; Lin and Shullman 2017; Lin et al 2016; Reed et al 2015; Horton et al 2015; Aerts et al 2013), London (Hall et al 2019; Hinkel et al 2018), Ho Chi Minh City (Ngo et al 2020; Bangalore et al 2019; Scussolini et al 2017), and Jakarta (Ward et al 2011). Other studies usually regard urban land or agricultural land as relatively homogeneous elements at risk, and evenly allocate GDP and assets to pixels of urban land or agricultural land (Winsemius et al 2016; Jongman et al 2015)

Results

Discussion

Conclusion