Source: adapted from Delfs, R. (1990) “Arteries of the Empire”, Far Eastern Economic Review, 15 March 1990, pp. 28-29.
The Grand Canal system (or Da Yun He) represents a remarkable imperial Chinese hydraulic engineering achievement. At its peak during the Ming dynasty (1368-1644 AD), the system totaled about 2,500 kilometers, with Beijing at its northernmost extension, Hangzhou at its southernmost point, and Luoyang at its easternmost point. It connected the political center of the empire in the north (especially from the Song dynasty; 960 AD) with the economic and agricultural centers of central and southern China. This was mainly achieved by linking two of China’s most important river basins, the Yellow River (Huang He) and the Yangtze River (Chang Jiang). The canal must ascend a gradual slope to an elevation of more than 40 meters north of the Yangtze. A system of locks (the Chinese are attributed to the first lock ever built in 983), feeder lakes, and lateral canals were constructed to ensure safe circulation. Under such circumstances, the control of a unified China became a possibility. The Grand Canal is acknowledged as a significant element in imperial China’s economic and political stability, mainly through grain distribution.
The canal has a long history of engineering projects that have controlled river systems and provided irrigation. Due to its hydrography, movements were easier on its East-West axis, while North-South communications were more arduous. The initial course of the canal, completed around 605 AD by the Sui dynasty (581 – 618 AD), provided a much-needed North-South axis by connecting several sections constructed at earlier times, starting from the Wu Kingdom era (486 BC). The initial goal of canal construction, which would change little over time, was shipping agricultural commodities through the empire, notably to the capitals. For the Sui dynasty, the goal was to link their western capital, Luoyang, to the rich agricultural regions of the lower Yangtze. The capital of the Tang dynasty (618 – 907 AD), Chang’an (Xi’an), was further west along a tributary of the Yellow River but linked to the Grand Canal. For the Yuan / Mongol (1279 – 1368 AD) and Ming dynasties, the Grand Canal linked the Northern Capital (Beijing) to southern China, enabling rice grown in southern China to supply the wheat-growing regions of the north. To promote trade and the use of the canal, the Imperial government issued an edict in 1415 forbidding the northward shipment of grain by sea. This had the unintended consequence of reducing the need to maintain a shipping fleet and prevented China from becoming a maritime power.
The density of the canal system was the highest south of the Yangtze Delta. Along the Yangzhou – Suzhou – Hangzhou trunk line, every town of importance was linked to a complex system of canals, creating a unique economic and social system where a large amount of wealth was derived from canal trade. At its peak during the 15th and 16th centuries, about 400,000 tons of grain transited on the canal each year. However, during the Qing dynasty (1644 – 1911), the canal gradually fell into disrepair, and some sections were abandoned. A major change in the course of the Yellow River in 1855 cut the Grand Canal into two sections. By the first half of the 20th century, the canal was no longer functioning coherently. Today, the canal is about 1,700 kilometers long and is still heavily used in the Yangtze Delta. About 100,000 river vessels transit on the canal each year, carrying about 260 million tons, mostly construction material. Thus, the canal offers an alternative to move ponderous goods that otherwise could not be handled effectively by China’s transport system.