Lessons Learnt From Typhoons Fitow and In-Fa: Implications for Improving Urban Flood Resilience in Asian Coastal Cities

Abstract

Frequent typhoons are significantly affecting the coastal cities via intensive rainstorms, tidal surges and strong wind. Natural factors such as climate change and global sea-level rise come alongside anthropogenic factors such as rapid urbanisation and land use/land cover change leading to detrimental consequences such as urban floods. This short communication offers various lessons learnt by Ningbo municipality from two strong typhoons that hit the city directly, namely “Fitow” in 2013 and “In-Fa” in 2021. On the one hand, the usage of “Big Data” and “Social Media” for bettering “Preparation” and “Prevention” reduced flood impacts significantly. On the other hand, the implementation of “Flood Insurance” speed up the “Recovery” processes. The successful “Preparation”, “Response” and “Recovery” helped Ningbo to enhance its flood resilience, and thus substantial impacts of injuries, household damages and associated economic loss were avoided. These three key terms should be heeded in typhoon/flood governance in which various stakeholders are involved with, and be incorporated into the city’s long-term strategic development plans to merge with the climate actions towards 2030s and beyond. This will be vitally important in reducing climatic hazards and improving coastal flood resilience under the future climatic uncertainties in Asian coastal cities. (196 words)

Comparison of sustainable flood risk management by four countries – the United Kingdom, the Netherlands, the United States, and Japan – and the implications for Asian coastal megacities

“…Currently, many Asian coastal megacities are operating predominantly within the flood control and defence paradigms, including Guangzhou, Shenzhen, and Hong Kong (Chan et al, 2013a;Yang et al, 2018);Shanghai;Bangkok (Keokhumcheng et al, 2012);Ho Chi Minh City (Storch and Downes, 2011;Nguyen et al, 2021); Jakarta (Texier, 2008;Wannewitz and Garschagen, 2021); and Singapore (Chan et al, 2018(Chan et al, , 2022. These cities all feature in the top coastal cities at risk by the 2050s (Hallegatte et al, 2013) because of not only their rapidly growing populations and economies and developmental pressure but also rising flood hazards from climate change (i.e.…”

“…typhoons) before the 1990s (Huu, 2011). Likewise, Chinese coastal cities faced urban floods that were enhanced by urbanisation and rapid development during the Open Door Policy established in the late 1970s, such as urban floods in Shanghai during 1981 and later events in 2020 and 2021 because of typhoons (Chan et al, 2021(Chan et al, , 2022. Guangzhou experienced frequent urban floods due to increased population density in major areas such as Tianhe or Baiyun (Zou, 2012).…”

“…Climate change is raising sea levels, making storm surges more hazardous , and is increasing the fre-quency, intensity, and magnitude of storms (typhoons), intense rainfall events, and sea surges (Basconcillo and Moon, 2021;Chan et al, 2021Chan et al, , 2022Ku et al, 2019;Webster, 2008;Webster et al, 2005). Natural resource extraction is also increasing flood hazard through the land subsidence it causes; for example, in the coastal area of Bangkok groundwater extraction has resulted in subsidence of 2 m since 1970 (Syvitski et al, 2009).…”

“…Different types of flood can be caused by coastal flooding -storm, high tides, sea-level rise, and insufficient protection; river/fluvial floods -snowmelt or high precipitation in catchment areas leading to flash floods or riverine floods; pluvial floods -extreme rainfall and failing drainage systems or compound floods from cyclonic monsoon effects enhancing intensive rainstorms and surges together; or rapid snowmelt . In Asian coastal megacities, flood risk and the frequency and impact of floods are increasing (Hanson et al, 2011;Hallegatte et al, 2013;Yang et al, 2015;Chan et al, 2021Chan et al, , 2022, through two routes. First, flood hazard is increasing as climate change raises sea surface temperature, driving oceanic thermal expansion and increasing the intensity and frequency of precipitation events and natural land subsidence (Meehl et al, 2007;Hulme et al, 2002).…”