On the territory of Vietnam, in the area of the confluence of the Mekong River with the South China Sea, there are huge spaces with a large system of canals.
To estimate their scale, you can copy, for example, these coordinates 10 ° 5 '49.03 "N 105 ° 25' 53.34" E into the Google Earth program or follow the link.
In some areas, these channels converge, forming, as it were, city centers. Only in cities are these streets - roads, but here, water communication.
Their purpose is obvious. Vietnam is an agricultural country (52% of workers in this industry, 21% of GDP) - rice, coffee, rubber plants, cotton, tea. All these fields are for growing rice. And these canals are an excellent irrigation system, and in the rainy season, a drainage system for excess water.
Narrow but often paved roads are laid along the large canals:
Promotional video:
Simple dwellings of Vietnamese peasants were built close to each other along the banks:
Without nearby canals (water flow), the fields would look like this picture:
Ideal conditions for rice, but water level regulation (after rains) is necessary.
If you evaluate the amount of excavation throughout this area, then it will turn out to be fantastic. The channels, though not deep, are still. Of course, we can say that more than 45 million Vietnamese are involved in agriculture all year round (out of the official 90 million inhabitants of the country) and over many decades, if not centuries, such a system was dug out to irrigate fields and drain excess water during the rainy season … But I have not even found a mention of it anywhere. When was it done? Maybe someone from the readers can help with this?
Is it possible that this is an older system of canals and the Vietnamese only began to use and expand it? Or maybe you dug it yourself quite recently? They do not sit in offices and the Internet, but work with pens every day. But I also did not find a single photograph of this process of such a construction.
One more point - the banks of the canals do not rise too high above the "mirror" of the fields. You can even say that they have the same height. Then where did the soil go?
Many canals are fairly straight lines for ten kilometers or more. There are 57 km of straight canals. How could they have been dug in the past so straight without surveying equipment? Or were there ways?
What's more interesting is that in some places the canals share a common system of "tributaries" from the Cambodian side:
The state border runs along the channel.
The only difference is that on the Cambodian side, the population density is less (fewer buildings). But the channel density is the same.