Doubles the current world's longest water tunnel
The Yinjiangbuhan tunnel (Bo Han Giang aquatic drainage) will bring water from the world's largest Three Gorges Dam to the Han Giang River - a major branch of the Yangtze River (Truong Giang River).
Coming to Dan Giang Khau reservoir in the lower reaches of Han Giang river, the water will flow north to Beijing through the 1,400km-long canal of the South - North water diversion project (Southern and North water cutes).
Päijänne - the world's longest water tunnel in Finland - stretches 120km in a 130m deep rock foundation. According to SCMP, the Yinjiangbuhan tunnel is twice as long and will be partly 1km underground.
It will take a decade and 60 billion yuan (US$8.9 billion) to build the Yinjiangbuhan tunnel, according to an article on July 8 of the Beijing-based Quang Minh Newspaper.
Niu Xinqiang - Chairman of the Truong Giang Institute of Surveying, Planning, Design and Research - said: "Yinjiangbuhan will connect the Three Gorges Dam and the South-North Water Transition Project, two important infrastructure facilities of China". The groundbreaking ceremony took place on July 7.
Zhang Xiangwei - Director of the Planning Department, Ministry of Water Resources, China - said that Yinjiangbuhan is a launching pad for other projects. There will be many more projects to expand and strengthen the nationwide spinal fluid supply network, Zhang told Quang Minh Newspaper.
Investing in large-scale infrastructure to stimulate growth
China's irrigation system is distributed unevenly. The East and South China regions are often flooded, while water shortages have seriously limited economic development and food production in the Western and Northern regions. The economic downturn caused by the pandemic has prompted governments to invest in large-scale infrastructure projects to stimulate growth.
Liang Shumin, an economic and development researcher at the Chinese Academy of Agricultural Sciences, said the total length of tunnels and canals under construction or planned for water supply in China could reach nearly 20,000km - equivalent to the distance of a round trip from Shanghai to Seattle in the US.
But whether these projects should be built or not is the subject of the ongoing debate, he said. The projects will cost more than yuan9,000 billion ($1.330 billion) over the next 30 years, equivalent to about 8% of China's GDP last year, Liang estimated.
But infrastructure could increase China's annual food production to more than 540 million tons, nearly the same as the current total agricultural output of the United States.
China is producing 660 million tons of food per year, more than any other country in the world. But to meet the growing living standards of 1.4 billion Chinese people, the country imports more than 100 million tons of grains per year.
According to Liang, the new water supply infrastructure could turn nearly 750,000km2 of wild land - larger than Chile's area - into suitable farms for growing wheat, rice, corn, beans and other crops.
Liang said that in the context of slowing down the growth rate of food consumption in the future (due to a decrease in population), China could become a net exporter of oil-rich grains and nuts by 2043. And after 2050, the net annual food export volume could reach more than 100 million tons.
This huge water redistribution infrastructure could change the landscape of China, some scientists say.
For example, the Southern-North Water Reduction Project has brought 54 billion cubic meters of water from the Yangtze River to meet the needs of more than 140 million people in northern China since it began operating in 2014 - nearly the same as the amount of water in the entire Huanghe River.
This leads to almost immediate changes, however, some changes are completely surprising. In some cities such as Hinh Dai, groundwater rose to the point of overflowing into some underground parking lots and basements.
The world's top projects in China
According to scientists participating in the project, China is building the world's longest tunnel in Xinjiang with more than 20 tunnel drilling machines - the largest number of drilling machines on the planet operating at the same time.
In addition, China has a plan to redirect melted snow from the highlands of Tibet to the Gobi and Taklamakan deserts.
This is the largest technical irrigation effort in human history. The overall efficiency and environmental impact of these projects are largely unknown, said a geologist in Beijing.
Many of these water projects, including the Yinjiangbuhan tunnel, have to go through some of the most difficult terrain on Earth.
Engineers and tunnel workers face a long list of challenges, including deep rock compression, operational disruption, flooding and heat that even machinery cannot withstand.
But Yang Qigui, a senior fellow fellow at the Truong Giang Institute for Surveying, Planning, Design and Research in Wenzhan, said China has addressed most of these technical issues with a large number of technical improvements over the past five years.
For example, China has used artificial intelligence in most of the water tunnels built recently, from project planning, construction and quality control to long-term operation.
According to Yang's team, some of China's water tunnels under construction in the western Gobi or Himalaya have reached nearly 300km and are more than 2km deep.
