Introduction:
The Yangtze River is the longest river in Asia and the third-longest in the world. Spanning 6,300 kilometers, it is a major transportation artery and natural resource for the people who live in its watershed. The flooding of the Yangtze River has had an immense impact on the river’s surrounding regions, from its inception to present day. Its geographical and climactic expanse means that flooding of the Yangtze River is guaranteed in some capacity year after year. But when was the last time it flooded?
Background Information:
Flooding of the Yangtze River has been recorded historically since the Sui Dynasty (581-618), which introduced extensive canal systems for the purpose of flood control along the Yangtze and its tributaries. Despite this, catastrophic flooding has occurred often throughout its long history: in 1931, the Chang Jiang (the Chinese name for the Yangtze River) experienced its deadliest floods to date, resulting in the death of an estimated 3.7 million people and substantial displacement of many communities living in its basin.
The Yangtze River Basin is particularly prone to flooding due to its terrain, irregular precipitation and human activities. Since the 1950s, the Chinese government has taken various measures to mitigate flood exposure within the basin, including the construction of major dams and embankments, as well as the 2007 relocation of 1.3 million people to higher ground and flood-secure areas.
Relevant Data:
Even with these measures in place, flooding of the Yangtze River continues to occur. In June 2020, a combination of heavy flooding along the river, up to 12 metres in some locations, and a powerful cyclone sent 9.2 million people fleeing for safety in China’s eastern and central regions. The flooding damaged or destroyed thousands of homes and critical infrastructure, with the direct economic losses estimated to be around $11.5 – $19 billion.
Perspectives from Experts:
Reportedly, this was the most destructive flood to hit the Yangtze River in decades. According to experts, changes in the regional climate pattern and the potential for future flooding are of great concern: the river’s relatively shallow drainage basin means that its flooding can take on a very rapid pace, and with more areas experiencing higher rainfall due to climate change, further flooding is likely in the near future.
Experts suggest that development of upstream reservoirs could prove effective in storing and managing water levels, which could reduce the risk of future flooding. Several countries have already tried such approaches with some success, providing a potential solution to decades of flooding along the Yangtze River.
Analysis:
It is clear that flooding of the Yangtze River continues to affect millions of people in the basin. While human intervention and technological advancements have been implemented to reduce the impact of its floods, it is clear that further action needs to be taken in order to fully address the issue. Climate change will continue to have an impact on the river and its tributaries, further compromising the safety of the people living in its basin.
The Role of Hydropower:
Hydropower stations have a key role to play in the flooding of the Yangtze River. As the dams that have been built to harness the river’s energy become increasingly efficient, the amount of water being discharged increases. These plants are able to discharge large amounts of water safely from reservoirs, preventing rivers from becoming overwhelmed with water during flood season. The exact level of water released, however, should be managed carefully to ensure flooding does not occur downstream. This is particularly important for communities that are based further away from the dams and those who are prone to riverbank erosion.
Emergency Response:
In order to prepare for and mitigate the risks associated with flooding of the Yangtze River, Chinese authorities have set up a flood forecasting and warning system. This system focuses on providing reliable information to both authorities and citizens in order to ensure that people living in the basin are aware of the threat of flooding and can take necessary steps to avoid it.
The system is also used to alert local population to extreme weather events and other potential dangers, such as landslides and chemical leaks, which could worsen the effects of the flooding. This system is particularly important in regions that are particularly prone to flooding, such as Yunnan, Sichuan and Jiangxi.
Preventative Measures:
In order to effectively address the threat of flooding of the Yangtze River, local and regional governments must take a coordinated approach. This includes investing in long-term infrastructure, such as intensive drainage systems, and promoting sustainable land use practices. Additionally, agricultural activities should be discouraged near riverbanks, as this could impede flood defences, accelerate soil erosion and impede the formation of natural barriers.
Public Awareness:
Public education and awareness play an integral role in reducing the potential for catastrophic flooding of the Yangtze River. Citizens must be made aware of the long-term impacts and risks associated with flooding, such as the importance of implementing resilient technologies, relocating vulnerable citizens to safe areas, and the need to conserve and retain water resources.
Understanding the roles and responsibilities of each stakeholder is necessary, and ensuring that all organisations are working collaboratively is essential. The need to continuously assess the impacts of both large and localised actions and consider how these interact with existing and future floods is key.
Environmental Management:
The protection of the environment should be paramount when it comes to managing flooding of the Yangtze River. This includes reducing air and water pollution, protecting and managing wetlands, investing in better wastewater management and utilising renewable energy sources. Pollution and wastewater discharges can interfere with the formation of flood defences and accelerate the effects of flooding, so it is essential that these are addressed.
There are also a variety of ways that local communities can protect themselves from flooding and minimise their exposure to risks, such as by growing trees and plants along riverbanks and maintaining man-made flood embankments. These strategies can aid in retaining water, encourage the flow of runoff and remobilise sediment, which could all help to reduce the impact of flooding.
Protection of Livelihoods:
It is essential that interventions to reduce flooding of the Yangtze River take into consideration the livelihoods of those living in the basin and the effects that flooding may have on them. This includes, but is not limited to, the provision of rescue and emergency services, access to safe shelter, adequate healthcare and assistance in the rebuilding of communities.
Securing villagers’ rights to land and water is an important step to securing their futures. Poorly planned development projects, such as building industrial zones and constructing large-scale hydropower plants, can also have a negative impact on the local people and environment, meaning due consideration should be given to any project that may have an effect on the ability of the local population to adapt and rebuild in the wake of a flood.
Post-Flood Actions:
In the immediate aftermath of a severe flood, rebuilding and rehabilitation efforts must be undertaken to get affected communities back on their feet. This may include the provision of grants and disaster relief funds, support to communities affected by the loss of crops and livestock, and investment in better flood forecasting and response systems.
Long-term actions must also be taken in order to prevent flooding of the Yangtze River from occurring in the future. This includes implementing sustainable land-use policies and investing in better infrastructure, such as flood diversion pathways. Working closely with local communities is also necessary to ensure their needs are met and their rights protected.
Flood Early Warning System:
An early flood warning system has been put in place for the Yangtze River Basin. This includes the implementation of remote sensing and satellite information systems, which provide data on rainfall and its resulting flood levels that can be used to detect potential flooding and prepare for any eventuality. Additionally, weather monitoring stations are in place to collect data on river levels and rainfall, which is then used to formulate precautionary measures and inform the local population. Other techniques, such as the use of hydrological models, can be used to forecast floods and identify areas that are most at risk of flooding.
The increased efficiency of these systems throughout the basin has enabled a rapid response to floods, reducing their magnitude and minimising the damage caused by them. However, these systems are still in their early stages of development, meaning they will need to be improved and better utilised in order to ensure effective surveillance in the future.
