The article Vietnamese "Venice" showed the huge network of water channels in Southeast Asia. According to some opinions, such a volume of earthworks does not fit into the existing picture of the capabilities of the country of Vietnam in the past, and perhaps even now. A clear answer "who built it?" not yet received.
Once again, it was a surprise to me that such a network of channels exists on an even larger territory, but only in China. And not only the networks of irrigation canals for irrigation and drainage of excess water - for the fields. But huge in length, deep and wide are navigable canals.
There is a canal that connects the northern regions of the country with the southern, with a length of 1782 km, and with branches to Beijing, Hangzhou and Nantong - 2470 km. The width in the narrowest part in Shandong and Hebei provinces is 40 m, in the widest part in Shanghai - 350 m. The depth of the fairway is from 2 to 3 m. The channel is equipped with 21 locks.
Here is the official information about its appearance:
The Great Canal consists of several sections built at different times. The southernmost section was laid in the 7th century, the northernmost - in the 13th century, and part of the central section from Huaiin to Jiangdu runs along the ancient Hangou Canal.
The first work to connect the north with the south began in the 6th century BC. The Magic Canal was built here. It is 32 kilometers long and connects two rivers flowing in different directions. As a result, the canal provides the movement of ships with a length of about two thousand kilometers and connects Beijing, Canton (Guangzhou) and Hong Kong.
The difficulty in constructing the canal was that the Xiang River, which originates in the Haiyan Mountains, flows to the north, and the Li River to the south. Both rivers are characterized by rapid currents, therefore, along the Xiang River, a bypass channel 2.4 km long had to be built for the passage of ships with a smaller drop in the channel than near the river. To ensure navigation, the waters of the Li River were directed to another 22 km long canal. Thus, having tamed both rivers, the builders were finally able to connect them with a channel 5 km long. A dam was poured across the Xiang River, dividing the channel into two streams - a large and a small one, and took most of it aside. Weirs were installed behind the embankment. In the Sinan area, several bridges were thrown across the canal, which was 1 m deep and 4.5 m wide. Thanks to the weir and separation system
Promotional video:
streams, only a third of the water of the Xiang River fell into the connecting channel, and it did not overflow.
It became possible year-round navigation on inland waterways with a total length of 2 thousand km (from the 40th to the 22nd parallel). The barges thus extended from the latitude of Beijing in the north of the country to Canton (Guangzhou) and to the sea in the south (where Hong Kong is now). The Magic Canal became a link in this system of Chinese rivers. At the very beginning of the VII century. The Grand Canal was continued south to Hangzhou. By the IX century. 18 locks were built on it. In the 13th century, when Beijing became the capital of China, the canal was brought to Beijing. So the Grand Canal took its current form. It originates in the north in the Beijing region, stretches south to Hangzhou, crossing the Yellow, Huaihe and Yangtze rivers, and encircles all of Eastern China.
I tried to go through the channel in the Google Earth program, but, to be honest, I’ll tell you, I didn’t succeed to the full extent. The reason is that these areas of China are practically a solid settlement: fields, farms, cities, and industries. There are a huge number of rivers and other channels. And the very path connecting north and south is lost in this payin. We managed to trace a certain path from the south (30 ° 24 '16.53 "N 120 ° 32' 55.66" E):
You can follow this link and start moving north
The channel has such a loop. A thinner canal is visible, laid directly. Why it was necessary to bypass it is not clear.
This is the place in the photograph.
In some places, the canal is already overgrown (in the very south, in Hangzhou).
One of many gateways.
Crossing channels. Link.
To the north, a huge network of such channels for fields appears:
Very similar to the channels in Vietnam. Their area is no less.
The length of the straight channel edges is impressive. This is about 11 km:
In some places the banks are "dressed" in a stone shirt.
Surprisingly, despite the dense population of these territories, there are very few photos in the panoramio service. It is possible that this service is also banned in China, like Google. Chinese users cannot post photos in it.
Until Beijing itself, it was not possible to trace the path along the canal and rivers, but after watching it, it no longer seemed important. Because important was the fact of the amount of work done by China. Perhaps, indeed, this has been done over a millennium, or perhaps they only adapted the existing system for shipping: they cleared the old one and dug the necessary new sections. The Great Wall of China seems to be a completely insignificant structure in comparison with this volume.
I would be glad for any help in finding information on this topic: photos, texts with a mention, etc.