Chapter 7 Chapter Two Sui, Tang and Song Grand Canals

In the early days of our country's history, when emperors chose their capital, they often set their sights on Chang'an.Because it is located in the center of Qinchuan, eight hundred miles away, the land is fertile; the plain is surrounded by mountains, so it can be defended in retreat and attacked in advance.It is for these reasons that when Emperor Wen of the Sui Dynasty Yang Jian ended the division of the Wei, Jin, Southern and Northern Dynasties, he also made Chang'an the capital of this unified dynasty. During the Wei, Jin, Southern and Northern Dynasties, the political situation was turbulent, and the economic situation in Guanzhong was difficult to compare with that of the Western Han Dynasty.In the Western Han Dynasty, the Zhengbai Canal alone could irrigate more than 40,000 hectares of farmland.During the Wei, Jin, Southern and Northern Dynasties, many irrigation projects here were abandoned due to lack of time for maintenance.Therefore, after the Sui Dynasty established Chang'an as its capital, the degree of relying on the transportation of grain from the east to the west far exceeded that of the Western Han Dynasty.This determined that soon after the founding of the Sui Dynasty, he began to dig Chang'an, the grain transportation channel between the Yellow River.

In the Western Han Dynasty, a canal called Caoqu was dug between the Yellow River in Chang'an due to the small amount of transportation on the Wei River.Later, due to the establishment of Luoyang as the capital in the Eastern Han Dynasty, the task of transporting grain to the West was greatly reduced, and the Caoqu Canal was soon scrapped due to disrepair.The Sui Dynasty had to reopen the new canal.In the first year of Emperor Kaihuang's reign (581 A.D.), Emperor Wen of the Sui Dynasty appointed General Guo Yan as the Supervisor of Kaicao Canal to be in charge of this project.He "led the hydraulic engineering department, dug a canal to divert the Weishui, passed through the north of Daxing City (Chang'an City), and reached Tongguan in the east, and transported it by water for more than 400 miles. ("Sui Shu·Guo Yan Biography") Although the Fumin Canal played an important role, it was difficult to meet the increasing needs of transporting grain from the east to the west due to its hastily constructed canal, shallow and narrow channel, and limited shipping capacity.In the fourth year of Emperor Kaihuang's reign (584 A.D.), construction had to be started again for reconstruction.

For this reconstruction, it is required to be deep, wide and straight, so that it can pass through the "Giant Boat of the Ark".Fang is a kind of boat with two boats side by side, with large volume and large capacity. "Warring States Policy · Chu Policy" said: "Boats carry soldiers, one boat carries fifty people, and food for three months." To navigate such a large and heavy-loaded boat, the channel must be deep and wide.The reconstruction project was presided over by Yu Wenkai, an outstanding engineering expert and designer of Daxing City.Before starting construction, he first sent "craftsmen to inspect the channels and observe the terrain" ("Sui Shu Shihuo Zhi"), so as to arrange the channels more reasonably on the basis of on-the-spot investigation.With the joint efforts of the top and bottom, the project progressed smoothly and was completed that year.The new canal is still diverted from the Wei River as the main water source. It is more than 300 miles long from Daxing City to Tongguan, and it is named Guangtong Canal.The transportation volume of Guangtong Canal greatly exceeds that of the old Canal, which plays an important role in alleviating the grain shortage in Guanzhong.In the fifth year of Emperor Kaihuang's reign (585 A.D.), there was a severe drought in Guanzhong, but there was no disaster.At that time, there was no drought and no famine, which was related to the distribution of more than 3 million Shi Guangtong warehouses.The Guangtong Warehouse was located in Huazhou (now Hua County) next to the Guangtong Canal. The grain here was transported from the east along the Guangtong Canal (Figure 1).

From the east of Tongguan to transport grain into the customs, the waterway below Guangtong Canal is the Yellow River.The Yellow River has the danger of three main pillars. The main pillars are two stone islands, standing in the middle of the river, blocking the waterway, forming three dangerous roads: the gate of gods, the gate of ghosts, and the gate of human beings. Sailing is very risky, and often the ship sinks and people die.The three main pillars were the "bottleneck" of grain transportation from east to west at that time.Therefore, in the fifteenth year of Sui Kaihuang (AD 595), he ordered to "cut the pillars".However, under the technical conditions at that time, the project of "cutting the mainstay" rarely progressed, so it had to be abandoned halfway.