Page 170 - JCAU-7-2

Journal of Chinese
Architecture and Urbanism Mitigating the risks

may be costly, it is far easier – and likely less expensive – case but rather an inevitable consequence of urban
than rebuilding after a catastrophic event. expansion and the evolution of large cities. Most urban
Natural disasters are often closely accompanied by social infrastructure, such as streets and roads, is impermeable,
crises, as illustrated by the collapse of China’s Liangzhu and preventing rainwater infiltration. Consequently,
Longshan cultures. Large-scale natural disasters can trigger stormwater runoff concentrates, exacerbating urban
severe social upheavals, such as the collapse of political flood hazards, which increasingly resemble flash floods
power, wars, dramatic population decline, and associated observed in some natural ecosystems (Zhang et al., 2021).
consequences. For example, the Bohai tsunamis that struck In recent years, the uncontrolled expansion of Chinese
China approximately 2,000 years ago coincided with the cities has made flood disasters increasingly common – so
collapse of the Western Han dynasty (202 BCE – 8 CE) and much so that many Chinese citizens humorously remark
contributed to the onset of the most chaotic and violent online about “going to an inland city in the summer to
period in Chinese history: the Northern and Southern see the sea.”
dynasties (420 – 589). During this period, farmers were 4. Mitigation strategies
often slaughtered as soldiers sought to seize their food
supplies. The turmoil persisted until 589 CE when emperor The development of human society increasingly depends
Yang Jian of the Sui dynasty (541 – 604) reunified China on knowledge-based industries, which do not require
and restored order. proximity to ports and reliance on water transportation
In modern times, global economic activity, including to distribute services. Unlike sectors focused on physical
in China, is heavily concentrated in low-elevation coastal products, knowledge-based economies depend on
areas. Disaster mitigation and response strategies in these engineering and technical personnel who produce software
regions often rely on standard models developed based and intellectual resources. This sector’s flexibility allows
on the frequency of return of a disaster (e.g., a “100-year for relocation to safer areas that are more distant from the
flood”). However, such models fail to adequately account coast and situated at higher elevations.
for the larger, less frequent disasters that have occurred However, coastal areas remain critical for importing
throughout history, as well as the increasing frequency and and exporting essential inputs (e.g., industrial chemicals,
severity of disasters driven by global climate change. fuels, and metals) that sustain cities and the industries
The world’s rapidly growing population continues they support. The coastal areas naturally evolve into hubs
to place immense pressure on the environment and of industrial activity and dense population centers. If
the infrastructure essential for supporting life in large disasters such as coastal flooding strike these areas, the
modern cities (e.g., water supply, drainage, and waste consequences are far-reaching. As demonstrated by the
disposal systems). Repeated episodes of urban flooding COVID-19 pandemic, the human costs – both locally and
have sounded the alarm regarding both inundation risks at the ends of global supply chains – can be severe and, in
and associated urban epidemics (Sun et al., 2020). For many cases, exceed the economic damage.
example, the July 20, 2021, heavy rainstorm in Zhengzhou To mitigate these problems, governments must
resulted in 398 deaths, affected nearly 15 million people, reconsider the subsidies that encourage migration to
and caused economic losses of 53.2 billion Chinese yuan coastal cities. In some cases, it may be more practical to
(Figure 1). Unfortunately, this event is not an isolated incentivize migration to inland cities beyond the reach of
floodwaters. This initiative can be achieved by investing
in efficient, inexpensive railway transport that connects
inland cities to coastal hubs for overseas shipping. Large
national programs, such as the China Railway Express, a key
component of the national “Belt and Road” strategy aimed
at increasing trade with Europe, could play an important
role in providing this alternative to coastal ports (Gao,
2022). However, these railway links often run through areas
prone to rainfall-induced landslides or structural damage
to critical infrastructures, such as bridges. As a result,
planners and managers must carefully consider the risk
posed by extreme events, such as “thousand-year floods,”
Figure 1. The extraordinarily heavy rainfall on July 21, 2021, in
Zhengzhou, China, resulted in 380 deaths and caused billions of Chinese and implement measures to reduce risk and mitigate the
Yuan in economic damage. Source: Photo by the authors severity of potential disasters.

Volume 7 Issue 2 (2025) 4 https://doi.org/10.36922/jcau.5320