The Desert is alive
February 8, 2010 7:11 AM Subscribe
The Qanat; a water management system from C7th BC still in use today;is one of the wonders of the world, and keeps the desert alive.
This fascinating 17 min video from UNESCO is a good introduction to the subject.
Cooling provided by Qanat’s is still in use in Yazd, Iran.
Modern warfare scores a gigantic fail in the battle for hearts and minds. (wiki)
Cooling provided by Qanat’s is still in use in Yazd, Iran.
Modern warfare scores a gigantic fail in the battle for hearts and minds. (wiki)
Haven't worked through the links, but the first linked article is fascinating. I'd never heard of such a thing, but it makes perfect sense for this kind of system to be built. Humans are amazing! Thanks for the post.
posted by lostburner at 7:49 AM on February 8, 2010
posted by lostburner at 7:49 AM on February 8, 2010
Arrakis, Dune, Spice planet...
posted by Splunge at 7:52 AM on February 8, 2010 [1 favorite]
posted by Splunge at 7:52 AM on February 8, 2010 [1 favorite]
Very cool. What an amazing feat of engineering for the time. As for the American base, I am glad they are finally getting things right.
posted by caddis at 8:15 AM on February 8, 2010
posted by caddis at 8:15 AM on February 8, 2010
a much better way of integrating with the land to modify it for our ends, rather than modern irrigation systems that generally stand in stark opposition to the environment.
Of course, some of those old-timey dudes were irrigating with salt water, which is not so great. Not to mention the fact that a lot of what is now desert was not at the time, which doesn't speak too well to integration with the environment.
posted by DU at 8:36 AM on February 8, 2010 [1 favorite]
Of course, some of those old-timey dudes were irrigating with salt water, which is not so great. Not to mention the fact that a lot of what is now desert was not at the time, which doesn't speak too well to integration with the environment.
posted by DU at 8:36 AM on February 8, 2010 [1 favorite]
4 feet by 2 feet for two years in the damp dark .... Yeah, I guess there are worse ways to spend your time but not that many. I'm sure the muqannis where highly regarded though.
posted by edgeways at 9:31 AM on February 8, 2010
posted by edgeways at 9:31 AM on February 8, 2010
>> It's also a great Q-with-no-U word for scrabble.
Nice. Qoph, qindar, and qaid were getting lonely.
posted by davelog at 9:37 AM on February 8, 2010
Nice. Qoph, qindar, and qaid were getting lonely.
posted by davelog at 9:37 AM on February 8, 2010
i've seen these all over Afghanistan on Google's imagery, but never knew what they were.
fascinating!
posted by bilgepump at 9:46 AM on February 8, 2010
fascinating!
posted by bilgepump at 9:46 AM on February 8, 2010
Burhanistan: It's kind of amazing for any time, and speaks to a much better way of integrating with the land to modify it for our ends, rather than modern irrigation systems that generally stand in stark opposition to the environment.
And that is because?
Both transport water from a natural source to an arid farming region via a man-made series of canals...
posted by IAmBroom at 9:49 AM on February 8, 2010
And that is because?
Both transport water from a natural source to an arid farming region via a man-made series of canals...
posted by IAmBroom at 9:49 AM on February 8, 2010
a much better way of integrating with the land
Well, it's cheaper, but it's not better. Modern plumbing can do things like move water UP, which the qanats can't, and can offer much better protection against contamination in transport. It also requires less maintenance.
The qanats are very good engineering, but fundamentally, they're just tunnels, no more and no less. Moving water through ditches and tunnels requires little in the way of industrialization or capital investment, and can work very well in a limited subset of applications, like pulling water from the mountains into lowlands. There are many, many applications where they simply wouldn't work, like the very common case of needing to move water from a river to the surrounding, higher farmland.
Me, I'm fond of showers, and while I admire the ingenuity in these systems, I'll take pressurized pipes any day.
posted by Malor at 10:13 AM on February 8, 2010
Well, it's cheaper, but it's not better. Modern plumbing can do things like move water UP, which the qanats can't, and can offer much better protection against contamination in transport. It also requires less maintenance.
The qanats are very good engineering, but fundamentally, they're just tunnels, no more and no less. Moving water through ditches and tunnels requires little in the way of industrialization or capital investment, and can work very well in a limited subset of applications, like pulling water from the mountains into lowlands. There are many, many applications where they simply wouldn't work, like the very common case of needing to move water from a river to the surrounding, higher farmland.
Me, I'm fond of showers, and while I admire the ingenuity in these systems, I'll take pressurized pipes any day.
posted by Malor at 10:13 AM on February 8, 2010
Called karez in Afghanistan - interesting discussion of them at p. 33 [pdf] in this report.
posted by YouRebelScum at 10:38 AM on February 8, 2010
posted by YouRebelScum at 10:38 AM on February 8, 2010
Moving water through ditches and tunnels requires little in the way of industrialization or capital investment
Huge earthworks projects which take many people years to accomplish? That's a lot of capital investment. I was impressed by the scale of these projects and the amount of work it takes to complete them. From the first link:
“The real principle behind all qanats is that if a man constructs one then he owns the land which its water irrigates,” declares Smith. “This dictum is very old and still applies.” (11) However, building a new qanat requires much capital. A wealthy person typically finances the building of a qanat system.
posted by lostburner at 10:40 AM on February 8, 2010
Huge earthworks projects which take many people years to accomplish? That's a lot of capital investment. I was impressed by the scale of these projects and the amount of work it takes to complete them. From the first link:
“The real principle behind all qanats is that if a man constructs one then he owns the land which its water irrigates,” declares Smith. “This dictum is very old and still applies.” (11) However, building a new qanat requires much capital. A wealthy person typically finances the building of a qanat system.
posted by lostburner at 10:40 AM on February 8, 2010
your Yazd hyperlink is borked... it's got a wsj.com URL dumped in the middle of it. Mod fix?
posted by Hartham's Hugging Robots at 11:00 AM on February 8, 2010
posted by Hartham's Hugging Robots at 11:00 AM on February 8, 2010
That's a lot of capital investment.
Well, not when you compare the (large!) cost of modern sewer and irrigation systems. Metal pipe itself takes a significant industrial base to make, and then the construction equipment takes another big chunk of economy to design and construct. Then you have the whole petroleum industry providing energy, and then yet another segment of the economy making the pumps. Then you have to train staff to run them. It scales up really well, and in the long run it's a lot more flexible and much cheaper to maintain, but it takes a cast of tens, maybe hundreds of thousands to make modern plumbing happen.
Compare that with the qanats... from the first link:
Scholar English noted one qanat near Kerman of around 2 miles that took one team of qanat diggers 17 years to construct
They don't say how many diggers that was, but assuming ten or a dozen workers, the actual capital investment for that particular one appears to be on the order of 200 man-years. If you assume a cost per worker per year of $50,000 (probably wildly high, compared to the time when that qanat was dug), that's about $10 million. And that's the ENTIRE cost; all they need is shovels, not a giant industrial economy behind them. All you need is Iron Age tools. That's a couple of orders of magnitude less total capital investment to make those projects happen.
posted by Malor at 11:37 AM on February 8, 2010 [1 favorite]
Well, not when you compare the (large!) cost of modern sewer and irrigation systems. Metal pipe itself takes a significant industrial base to make, and then the construction equipment takes another big chunk of economy to design and construct. Then you have the whole petroleum industry providing energy, and then yet another segment of the economy making the pumps. Then you have to train staff to run them. It scales up really well, and in the long run it's a lot more flexible and much cheaper to maintain, but it takes a cast of tens, maybe hundreds of thousands to make modern plumbing happen.
Compare that with the qanats... from the first link:
Scholar English noted one qanat near Kerman of around 2 miles that took one team of qanat diggers 17 years to construct
They don't say how many diggers that was, but assuming ten or a dozen workers, the actual capital investment for that particular one appears to be on the order of 200 man-years. If you assume a cost per worker per year of $50,000 (probably wildly high, compared to the time when that qanat was dug), that's about $10 million. And that's the ENTIRE cost; all they need is shovels, not a giant industrial economy behind them. All you need is Iron Age tools. That's a couple of orders of magnitude less total capital investment to make those projects happen.
posted by Malor at 11:37 AM on February 8, 2010 [1 favorite]
Yeah, the Qanat makes sense in desert areas where human labour is cheap and modern technology is too expensive and/or nonexistent. It takes a lot of effort to dig those channels and then keep them free of silt for centuries, but when you've got plenty of hands to spare the relative cost isn't too high. I'm more impressed by these hypothetical rich people who were willing to make large investments and then wait decades for construction to finish. I guess putting your money into a Qanat would be a way of investing in the future, so your children and grandchildren could be rich too.
What a fascinating subject!
posted by Kevin Street at 3:59 PM on February 8, 2010
What a fascinating subject!
posted by Kevin Street at 3:59 PM on February 8, 2010
Are these the same things I've read about in Iran where they're also used as a cooling system for basements where food is stored, and possibly also for something related to ice production?
The theory was, I think, that the tunnels also carry air that's cooled by the water, and that air is pushed up through wells in the basements of houses, so that a cooling pit in the basement can be kept at very low temperatures.
Quick Googling comes up with nothing, but I'm pretty sure I've read about this. There were also some buildings constructed to promote cooling by evaporation, and as I mentioned, I think they got cold enough to actually produce ice.
posted by Joakim Ziegler at 5:02 PM on February 8, 2010
The theory was, I think, that the tunnels also carry air that's cooled by the water, and that air is pushed up through wells in the basements of houses, so that a cooling pit in the basement can be kept at very low temperatures.
Quick Googling comes up with nothing, but I'm pretty sure I've read about this. There were also some buildings constructed to promote cooling by evaporation, and as I mentioned, I think they got cold enough to actually produce ice.
posted by Joakim Ziegler at 5:02 PM on February 8, 2010
Joakim Ziegler see wiki linked above , also pictures of Yazd now jessamyn has kindly fixed the link. Here is a bit more.
Malor: its all bit of a false equivalency. Your 10 or dozen workers need to be sustained for 17 years presumably on the crops not grown from lack of water. Also loss of of these persons output in agriculture or production skill to sustain their basic lifestyle and that of their families.
Also , from the "alive" link: “No one in their right mind would do this for a living. The men who did this didn’t do it for a living. They did it for spiritual reasons. They felt by drawing life out of the ground they were getting closer to God."
posted by adamvasco at 2:34 AM on February 9, 2010
Malor: its all bit of a false equivalency. Your 10 or dozen workers need to be sustained for 17 years presumably on the crops not grown from lack of water. Also loss of of these persons output in agriculture or production skill to sustain their basic lifestyle and that of their families.
Also , from the "alive" link: “No one in their right mind would do this for a living. The men who did this didn’t do it for a living. They did it for spiritual reasons. They felt by drawing life out of the ground they were getting closer to God."
posted by adamvasco at 2:34 AM on February 9, 2010
Malor wrote: "Well, it's cheaper, but it's not better. Modern plumbing can do things like move water UP, which the qanats can't, and can offer much better protection against contamination in transport."
Or our modern plumbing could be open canals through the middle of deserts that lose millions of gallons of water a day. We seem to prefer to do things that way here in the US.
posted by wierdo at 12:11 PM on February 9, 2010
Or our modern plumbing could be open canals through the middle of deserts that lose millions of gallons of water a day. We seem to prefer to do things that way here in the US.
posted by wierdo at 12:11 PM on February 9, 2010
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