[Tagging] "Feature Proposal - RFC - Qanat"

Joseph Eisenberg joseph.eisenberg at gmail.com
Sun Jun 21 00:24:16 UTC 2020


> In case of a well, as the aquifer is below your starting point, I’d think
you would need some kind of pump and not just gravity (at the beginning)?

Look at the diagram:
https://en.wikipedia.org/wiki/Qanat#/media/File:Qanat-3.svg or
https://en.wikipedia.org/wiki/Qanat#/media/File:Qanat_cross_section.svg

The first part of qanat, on the uphill side, is alway slightly higher than
the point where it exits the hill. The water flows downhill by gravity. The
channel is usually tall enough to at least partially stand up, since it was
dug by people with hand tools.

The first shaft might be quite deep, and may have originally been dug as a
well prior to being turning into a qanat, but in some cases the whole
system was built at once.

> I think I would remove the word “pipe” in the paragraph that explains
free flow,  because I believe you can have “free flow” in pipes, but I am
not sure of both, the definitions of free flow and pipe.

A qanat is not built with pipes or a pipeline for transmission of the water.

– Joseph Eisenberg

On Sat, Jun 20, 2020 at 3:31 PM Martin Koppenhoefer <dieterdreist at gmail.com>
wrote:

>
>
> sent from a phone
>
> On 20. Jun 2020, at 20:39, Joseph Eisenberg <joseph.eisenberg at gmail.com>
> wrote:
>
>
>    - The immediate source of water is groundwater (aquifer or well), not
>    a spring, stream or river
>    - Water flows by gravity in free flow (not pressurized or pipe flow)
>    - The channel is underground (minimising evaporation)
>    - Construction and maintenance is through vertical shafts, which are
>    then visible on the surface
>
>
>
> according to pictures I found they are tall enough so that a person can
> walk inside?
>
> In other types of aqueducts the water channel is often enclosed/inside
> pipes so that evaporation shouldn’t be an issue either, but the underground
> position will keep the water more chilled in a qanat.
>
>
> In case of a well, as the aquifer is below your starting point, I’d think
> you would need some kind of pump and not just gravity (at the beginning)?
>
> They are clearly not pressurized, but this is common for sewer pipes as
> well (i.e. the same kind of “free flow” in pipes, not sure about the
> definition of pipe, couldn’t you call a qanat also a kind of “pipe”?) I
> think I would remove the word “pipe” in the paragraph that explains free
> flow,  because I believe you can have “free flow” in pipes, but I am not
> sure of both, the definitions of free flow and pipe.
>
> Cheers Martin
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