Grand Canal (China) - History - Grand Canal in The Sui Dynasty

Grand Canal in The Sui Dynasty

The sections of the Grand Canal we see today in Zhejiang and southern Jiangsu provinces were in large part a creation of the Sui Dynasty (581-618), a result of the migration of China’s core economic and agricultural region away from the Yellow River valley in the north and toward the southern provinces. Its main role throughout its history was the transport of grain to the capital. The institution of the Grand Canal by the Sui also obviated the need for the army to become self-sufficient farmers while posted at the northern frontier, as food supplies could now easily be shipped from south to north over the pass.

By the year 600, there were major build ups of silt on the bottom of the Hong Gou canal, obstructing river barges whose drafts were too deep for its waters. The chief engineer of the Sui Dynasty, Yuwen Kai, advised the dredging of a new canal that would run parallel to the existing canal, diverging from it at Chenliu (Yanzhou). The new canal was to pass not Xuzhou but Suzhou, to avoid connecting with the Si River, and instead make a direct connection with the Huai River just west of Lake Hongze. With the recorded labor of five million men and women under the supervision of Ma Shumou, the first major section of the Grand Canal was completed in the year 605—called the Bian Qu. The Grand Canal was fully completed under the second Sui emperor, from the years 604 to 609, first by linking Luoyang to the Yangzhou (and the Yangzi valley), then expanding it to Hangzhou (south), and to Beijing (north). This allowed the southern area to provide grain to the northern province, particularly to troops stationed there. Running alongside and parallel to the canal was an imperial roadway and post offices supporting a courier system. The government also planted an enormous line of trees. The history of the canal's construction is handed down in the book Kaiheji ('Record of the Opening of the Canal').

The earlier dyke-building project in 587 along the Yellow River—overseen by engineer Liang Rui—established canal lock gates to regulate water levels for the canal. Double slipways were also installed in order to haul boats over when the difference in water levels were too great for the flash lock to operate.

Between 604 to 609, Emperor Yang Guang (or Sui Yangdi) of the Sui dynasty ordered a number of canals be dug in a ‘Y’ shape, from Hangzhou in the south to termini in (modern) Beijing and in the capital region along the Yellow River valley. When the canal was completed it linked the river systems of the Qiantang River, the Yangtze River, the Huai River, the Yellow River, the Wei River and the Hai River. Its southern section, running between Hangzhou and the Yangtze, was named the Jiangnan River (the river ‘South of the Yangtze’). The canal’s central portions stretched from Yangzhou to Luoyang; the section between the Yangtze and the Huai continued to the Shanyang River; and the next section connected the Huai to the Yellow River and was called the Tongji Channel. The northernmost portion, linking Beijing and Luoyang, was named the Yongji Channel. This portion of the canal was used to transport troops to what is now the North Korean border region during the Goguryeo-Sui Wars (598–614). After the canal's completion in 609, Emperor Yang led a recorded 105 km (65 mi) long naval flotilla of boats from the north down to his southern capital at Yangzhou.

It should be recognized that the Grand Canal at this time was not a continuous, man-made canal but a collection of often non-contiguous artificial cuts and canalised or natural rivers.