How the South-to-North Water Diversion Project Helps the Central Plains Granary Safeguard China's Food Security

In 2014, the “Central Plains Granary” Henan once again celebrated a bumper summer grain harvest, achieving twelve consecutive years of increase. However, behind the consecutive years of bumper harvests, the hidden worries about agricultural water resources have become increasingly prominent, with North China, the Central Plains and other regions suffering severe droughts for many consecutive years. Professionals point out that the South-to-North Water Diversion Project, which is about to start conveying water, will, through the rational allocation of water resources, change the water shortage situation in northern grain-producing areas and increase grain production capacity.

Wang Hao, an academician of the Chinese Academy of Engineering, said that after the South-to-North Water Diversion Project begins conveying water, through inter-regional water transfer, it will greatly improve the water shortage problem in northern grain-producing areas, raise grain production capacity, and further tap the potential for increasing grain output, thereby safeguarding national food security.

“The drought problem facing Henan is no longer a seasonal or basin-wide drought; hydrological drought has already appeared.” said Huang Wei, deputy director of the Planting Industry Division of the Henan Provincial Department of Agriculture. In 2014, Henan, which had suffered drought for many consecutive years, was hit by its most severe drought in 63 years, with the area of autumn crops affected by drought in the province reaching a peak of 27.14 million mu.

To fight the drought and protect production, most areas of Henan had to rely on extracting groundwater, leaving the groundwater resources in some areas in a worrisome state. “The groundwater level in western and southern Henan has dropped substantially, and the decline in motor-pumped wells has exceeded 30%.” said Zhao Lianfeng, a supervisory commissioner of the Henan Provincial Flood Control and Drought Relief Headquarters Office.

The reporter learned from the Office of the South-to-North Water Diversion Project of the State Council that 13% of the water volume in the first-phase projects of the eastern and middle routes of the South-to-North Water Diversion will be allocated to agriculture, which can indirectly increase ecological and agricultural water use by 6 billion cubic meters per year; after water conveyance begins, tens of millions of mu of farmland will receive effective irrigation.

Hua County is the largest grain-producing county in Henan Province. In recent years, to ensure the safety of urban water supply, Hua County has given priority to allocating urban water every year, and agricultural water resources have been severely restricted. “After the South-to-North Water Diversion begins conveying water, the annual water volume allocated to Hua County will reach more than 50 million cubic meters, which can fully guarantee urban domestic water use, and agricultural production water sources will no longer be encroached upon.” said Han Xiaowei, deputy director of the Hua County Water Affairs Bureau.

According to Huang Wei, the first problem in increasing wheat production is water. At present, Henan Province still has 16 million mu of dryland wheat, with an average yield of 300 to 400 jin per mu. Once the water source supply from the South-to-North Water Diversion is guaranteed, the per-mu yield of this dryland wheat is expected to reach 800 to 1,000 jin.

“Most of the 34 water-receiving counties of the South-to-North Water Diversion in Henan Province are major agricultural production counties. The annual water source supply of 3.769 billion cubic meters will significantly improve Henan's water ecology and raise Henan's grain production capacity.” said Liu Zhengcai, deputy director of the Henan Provincial Office of the South-to-North Water Diversion.

Xu Xinyi, dean of the College of Water Sciences at Beijing Normal University, said that whether on the eastern route or the middle route, in addition to the agricultural and ecological water supply tasks stipulated in the plans, the South-to-North Water Diversion also has important agricultural and ecological water replenishment tasks. “When a severe drought occurs in the North China Plain and the incoming water volume of the Danjiangkou Reservoir happens to be abundant, the state can supply water through the eastern and middle route projects to hundreds of millions of mu of farmland threatened by drought.”

⟦NL> This summer, to alleviate the drought in Nansi Lake in Shandong Province, Shandong urgently diverted water from the Yellow River through two routes, the Liangji Canal in Jining and the Dongyu River in Heze, to supplement the ecological water use of Nansi Lake; in August, to respond to the severe drought in the middle and lower reaches of the Han River, especially in Xiantao City, Hubei Province used in advance the Yangtze-to-Han River Water Diversion Project, one of the compensation projects of the South-to-North Water Diversion, to divert water from the Yangtze River and guarantee water use for more than 6 million mu of farmland.

Wang Hao said that after the implementation of the South-to-North Water Diversion Project, the annual 6 billion cubic meters of ecological and agricultural water use will gradually restore and improve the ecological environment of northern regions, further raise the production capacity of northern grain-producing areas, tap the potential for increasing grain output, and promote the balance of grain supply and demand. Under conditions of global warming and increasing extreme weather, it can increase the country's ability to withstand risks in grain production and provide a guarantee for sustainable economic and social development.