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Dujiangyan irrigation system (wikipedia.org)
66 points by bane on April 22, 2014 | hide | past | favorite | 12 comments

I always considered it fascinating how so many of China's cultural heroes were people who built great works and disseminated knowledge. (Not that Chinese mythology is necessarily unique in this manner, of course.)

- Shennong, who invented agriculture.

- Cangjie, who invented Chinese characters.

- Yao, Shun, and Yu, who tamed the river floods and irrigated the fields.

Philosophic Taoism introduces Dao, the origin and derivatives of the essence of nature, its laws and forms, on top of which the Taoist religion developed a complete methodology for normal people to ascend into heaven by practicing introductory transcending courses and eating natural/artificial elixirs.

The ultimate stage of ascended beings will be Tao itself, the advanced stage is celestial being, and the intermediate stage is god, and the beginning stage is 'trueman'.

Celestial beings have freedom to create new rules/universes with certain backfiring possibility which may cease their own existence. Normally they don't care about earth and human beings except for promoting new gods. Gods are anthropomorphic and every one has a job. They either enforce specific rules or govern certain domains to maintain the human world. Truemen are long lived human beings and they can self-educate themselves ascending to be new gods or destroyed by Tao if they fail to purify themselves.

Therefore, Taoism has two ways of creating anthropomorphic gods: promoted/guided by Celestial beings or self-help to ascend.

The first way is for great inventors and heroes etc. The second way is for Taoist priests and emperors, but neither of them succeeded.


In China history, many famous emperors were poisoned by mercury because Taoist alchemists believed it's an essential ingredient for any elixir (on purpose?) ;D

A map of the irrigation system http://www.travelchinaguide.com/images/map/sichuan/dujiangya...

Being there many times when I was living in Sichuan province. Its significance though never really struck me util I was in adulthood. It's indeed a magnificent project considering it was built more than 2000 years ago. It is still in use today!

On OpenStreetMap: http://www.openstreetmap.org/#map=15/30.9966/103.6092&layers...

Good to zoom out and see the context of the mountains vs. plain.

"Modern studies suggest that, on purchasing power parity basis, one tael of silver was worth about 4130 RMB (modern Chinese yuan) in the early Tang Dynasty, 2065 RMB in the late Tang Dynasty, and 660.8 RMB in the mid Ming Dynasty[citation needed]." [1]

So taking the nearest estimated value of a "tael", 100,000 taels of silver * 4130 CNY / 6 CNYUSD, the irrigation system costed around USD $68m in today's dollars to build, back during the Qin dynasty.

There were an estimate of 20 million people living in Qin china.[2]

By the time of the Han dynasty, just 200 years later, the population tripled to almost 60 million [3].

[1] https://en.wikipedia.org/wiki/Tael

[2] http://en.wikipedia.org/wiki/Qin_dynasty

[3] http://en.wikipedia.org/wiki/Han_dynasty

Very cool:

  Cutting the channel proved to be a far greater problem as
  the tools available to Li Bing at the time, prior to the
  invention of gunpowder, were unable to penetrate the hard
  rock of the mountain so he used a combination of fire and
  water to heat and cool the rocks until they cracked and
  could be removed.

This is the same method believed to have been used by Hannibal's army when it crossed the Alps on its way to Rome: http://en.wikipedia.org/wiki/Fire-setting

Ancient irrigation systems are often the ignored wonders of the world.

My favourite is the Zarch Qanat, which is about 3000 years old and has a tunnel into the water table which is about 71 kilometres long with over 2000 vertical shafts into the tunnel.



Dujiangyan is astonishing to see in person. The scale of such an ancient project is mind boggling. Sadly, much of the surrounding area was destroyed in the 2008 earthquake as the epicenter was very nearby.

There's a good documentary on this: https://www.youtube.com/watch?v=P4FRO1eYdgQ

Not the correct project.

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