★ What influence did the Sui Grand Canal have on the political and economic development of China?

The Beijing-Hangzhou Canal is the longest man-made river in the world and one of the oldest canals. Together with the Great Wall of Wan Li, it is known as the two major ancient projects in China. The Beijing-Hangzhou Canal starts from Beijing in the north and ends in Hangzhou in the south. It runs through Beijing-Tianjin-Hebei, Shandong, Jiangsu and Zhejiang provinces and connects five major water systems: Haihe River, Yellow River, Huaihe River, Yangtze River and Qiantang River. Total length 1800 km. As early as more than 2,400 years ago, Wu fought for the Northern Expedition to Qi, and dug a canal (named Hangou) near Yangzhou, Jiangsu. On this basis, it continued to develop, extending from north to south, especially after the second large-scale expansion and transformation in Sui and Yuan Dynasties, and basically completed the scale of the Beijing-Hangzhou Canal today. Many sections of the Beijing-Hangzhou Canal use the original natural rivers and lakes, and some sections are artificially excavated. The canal water flow is mainly replenished by connected natural rivers.

The Beijing-Hangzhou Canal has always been the main canal for water transportation in past dynasties, and played an important role in the economic and cultural exchanges between the North and the South. /kloc-shipping rose in the 0/9th century. With the opening of the Jin-Pu Railway, the role of the Beijing-Hangzhou Canal gradually decreased. After the migration of the Yellow River, the water resources in the reach of Shandong Province were in short supply, and the siltation was shallow, and the north-south navigation was cut off and silted up to the ground. The section of Jiangsu with large water volume and good navigation conditions can only sail in Xiao Mu. The abandonment and depression of the Beijing-Hangzhou Canal is a portrayal of the semi-colonial and semi-feudal system in China. After liberation, some river sections were widened and deepened, many modern docks and shiplocks were built, and shipping conditions were improved. Seasonal navigation mileage reaches 1 100 km or more. 660 kilometers south of Pixian County, Jiangsu Province, the 500-ton fleet can be unimpeded.