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Author Topic: The layer below an aquifer..  (Read 705 times)

Quarque

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The layer below an aquifer..
« on: September 11, 2017, 03:28:42 pm »

Here is the situation:

Code: [Select]
Z=100 #######
Z=099 #######
Z=098 ~~~~~~~
Z=097 ~~~~~~~
Z=096 ####### <= damp
Z=095 #######

# = stone
~ = aquifer

The stone on Z=096 is not an aquifer, but it is damp due to the aquifer soil layer directly on top of it. I want to mine out as much of the Z=096 layer as possible, but without precautions, water will fall down from the aquifer above it.

I could remove the two aquifer layers embark-wide, using either the Cave-In Method (which I am afraid would fail due to the soil layer transformation bug), or using the Drainage method, which would take ages..

Is there any option I overlooked, a method to prevent water from falling down from an aquifer layer above you?
« Last Edit: September 12, 2017, 08:50:34 am by Quarque »
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anewaname

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Re: The layer below an aquifer..
« Reply #1 on: September 11, 2017, 04:47:27 pm »

You can dig out z=96 completely without fear, so long as you do not carve or construct any upward stairs or ramps on z=96. It is only upward stairs and ramps that will allow access to the floor of the aquifer on z=97, causing the breach. I perceive it as, "if a dwarf has the ramp or stairs needed to allow him to dig upward, then the tile above is "accessible", and the water can come down.

I habitually avoid digging in the layer below an aquifer, due to that one time I constructed an up/down stairs over a new shaft, when down stairs would have worked as well. That up/down stairs made the layer above accessible and the flooding began. Once you dig out that "damp stone" layer, you will need to remember to not build "upward things" on this layer of the fort, and that is easy to forget if you are playing a large fort for a long time, and worse if you have a well-developed "conserving my dwarf-power" habit of building only up/down stairs in preference to those inefficient stair constructions that only allow movement in one direction.

This same condition applies to warm stone.
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PatrikLundell

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Re: The layer below an aquifer..
« Reply #2 on: September 11, 2017, 05:12:48 pm »

Apart from the risk of manager accidents, digging damp/warm stone is a pain in the posterior due to the constant cancellation spam. You also have the risk that the ground above is uneven which can cause the aquifer layer to be uneven, which can cause your "safe" mining to take a bite out of an aquifer.
Strip mining the aquifer layers (and sealing their edges) is probably the safest method.
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Fleeting Frames

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Re: The layer below an aquifer..
« Reply #3 on: September 12, 2017, 05:00:59 am »

OP, your links are borked.

Also, I think your only options are to remove the aquifer areas. I mean, technically you could make a drain, dig z95 with up/down stairs and then dig z96 with (up/)downstairs so that you have a drain that doesn't flush miners around, but the falling water will drain your FPS anyway unless and until you seal up the mine and have it filled with still water. (And that would have constant cancellations as PatrikLundll says; while using ramps to avoid them can result in miners being pushed around unless you make a digging pattern of tiled 3x3s of updownstairs surrounded by 8 ramps.)

You can dig out z=96 completely without fear, so long as you do not carve or construct any upward stairs or ramps on z=96.
False; just tested in 43.03:
||
This is a screenshot of stone layer right under an aquifer. In the center there's the up/down stair used for piercing, and both sides there are downward ramp and downstairs pierced from below. Both leak water, as you can see by the wet/muddy tiles.

« Last Edit: September 12, 2017, 05:02:48 am by Fleeting Frames »
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Quarque

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Re: The layer below an aquifer..
« Reply #4 on: September 12, 2017, 09:04:53 am »

Borked? I learned a new word today.

hmm.. sounds like there is no easier way than stripmining.

To add some context: I calculated I can produce about 93.000 bars of steel in this embark without mining the problematic layer and some 109.000 bars if I do.. so it's not like there is a practical need to mine that final layer, it just feels undwarflike to leave tasty bits of magnetite in the ground.
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PatrikLundell

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Re: The layer below an aquifer..
« Reply #5 on: September 12, 2017, 12:45:11 pm »

If you find that's to be a tasty dwarfy semi mega project, by all means, go ahead!
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anewaname

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Re: The layer below an aquifer..
« Reply #6 on: September 13, 2017, 04:50:52 am »

You can dig out z=96 completely without fear, so long as you do not carve or construct any upward stairs or ramps on z=96.
False; just tested in 43.03:
||
This is a screenshot of stone layer right under an aquifer. In the center there's the up/down stair used for piercing, and both sides there are downward ramp and downstairs pierced from below. Both leak water, as you can see by the wet/muddy tiles.
Yes... I was confused!
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How did I manage to successfully apply the lessons of The Screwtape Letters to my perceptions of big grocery stores?
     and
If you're going to kill me, I'm allowed to scream.