Odd water question (involves magic)

[Traab]

Ok, so, there is a story im reading, a harry potter fanfic, where he is going around creating man made lakes in various parts of africa, then placing runes at the bottom of the ocean that will transfer water to the lakes and remove the salt when it does. The idea being to provide a source of clean drinking water to areas that often have little. What i was wondering was, what would the effect be on the oceans? I mean, would the salt levels be gradually altered over time? Would this effect the sea level itself? Can anyone think of long term ramifications for the world in general, or the oceans/africa specifically if something like this was done?

[halfeye]

Ok, so, there is a story im reading, a harry potter fanfic, where he is going around creating man made lakes in various parts of africa, then placing runes at the bottom of the ocean that will transfer water to the lakes and remove the salt when it does. The idea being to provide a source of clean drinking water to areas that often have little. What i was wondering was, what would the effect be on the oceans? I mean, would the salt levels be gradually altered over time? Would this effect the sea level itself? Can anyone think of long term ramifications for the world in general, or the oceans/africa specifically if something like this was done?
The oceans are huge, there would be almost no effect on them.

[The Great Wyrm]

Freshwater is already transported from the oceans to the land, by evaporation and rainfall. The only difference here is that the freshwater would be removed from the bottom of the ocean instead of the surface. As halfeye observed, the relatively minor amount removed is unlikely to have a significant effect.

[halfeye]

This is great:

http://water.usgs.gov/edu/gallery/global-water-volume.html

http://water.usgs.gov/edu/pictures/full-size/global-water-volume-fresh-large.jpg

The tiniest blue sphere is fresh water in lakes and rivers, Potter could double it and the effect on the big sphere would still be almost nothing. It is amazing how small all the water is compared to the Earth itself.

[Traab]

Ok, so the oceans wouldnt be effected by any real measurable amount, what about africa itself? Would the sudden influx of year round water in areas that are often quite arid alter the climate in the area at all? How many lakes (or alternatively how much water) would it take to make a difference there if ever at all?

[Khedrac]

It is worth raising the question of where the salt and other minerals that are removed from the sea water on transportation go. If it is left in the sea then the net effect is the same as more water evaporating fromt he sea and falling as rain on the and.
If the minerals are lost then (very very slowly) this will being to dilute the seas - but probably not in a way that will be noticed for centuries at least. Oddly removing the dissolved carbon dioxide in this fashion would reduce the problem of increasing sea acidity and be a useful source of atmospheric carbon capture (as it allows the sea to absorb more from the air).

[factotum]

There's a definite problem I can see here. Absent any specific magic saying otherwise, the water is presumably going to keep flowing through the "runes" until the pressure is equalised on both sides--e.g. the fresh water on the outgoing side is the same depth as the salt water on the other side. So, what does "bottom of the ocean" mean in this context? If you put your rune at the bottom of the Challenger Deep then your African lake has to get to 36,000 feet deep before the water stops flowing, and that would be a bit of an issue!

Even if the rune is placed in water that isn't quite so deep as that, what will stop it moving? It might be placed at an appropriate depth, then a submarine landslide takes it 200 feet further down and suddenly your African village drowns as their lake overflows.

[Traab]

There's a definite problem I can see here. Absent any specific magic saying otherwise, the water is presumably going to keep flowing through the "runes" until the pressure is equalised on both sides--e.g. the fresh water on the outgoing side is the same depth as the salt water on the other side. So, what does "bottom of the ocean" mean in this context? If you put your rune at the bottom of the Challenger Deep then your African lake has to get to 36,000 feet deep before the water stops flowing, and that would be a bit of an issue!

Even if the rune is placed in water that isn't quite so deep as that, what will stop it moving? It might be placed at an appropriate depth, then a submarine landslide takes it 200 feet further down and suddenly your African village drowns as their lake overflows.

Too be honest I forget, I think they actually were placing the runes on the seabed 50 meters down. Still pretty deep for a lake! But I would imagine its basically something like there is a "fill to here" rune on the lake or something along those lines. It didnt go into detail beyond "Runes to transfer water sans salt" So we just have to assume there are safety measures in place to prevent that sort of thing. They mentioned having to do stuff to make sure the lake didnt drain into the earth or grow stagnant as well.

Honestly, I prefer it that way. Some authors really go deep when they world build, they feel like they have to explain everything in a logical system that makes perfect sense down to the last detail. I prefer "because magic" beyond a few details at most. Its magic, people! You dont have to explain why it works when physics says no way, because ITS MAGIC! The only time you should really bother to explain why is when it seems to violate its own rules somehow.

[5a Violista]

There's a definite problem I can see here. Absent any specific magic saying otherwise, the water is presumably going to keep flowing through the "runes" until the pressure is equalised on both sides--e.g. the fresh water on the outgoing side is the same depth as the salt water on the other side. So, what does "bottom of the ocean" mean in this context? If you put your rune at the bottom of the Challenger Deep then your African lake has to get to 36,000 feet deep before the water stops flowing, and that would be a bit of an issue!

Alternatively, it could work like a positive displacement pump (constantly outputting the same volume). This also has precedence with magic, such as the Decanter of Endless Water which always outputs a set volume of water per round regardless of the pressure.

Then, what happens afterwards depends on the flow rate of the water, the soil composition, the geometry of the landscape, and so on:
1) If there's significant seeping into the ground: the land around the lake becomes muddy. The water table may rise. Crocodiles may move into this new mudhole. The lakewater becomes murky, because the constant high flow is causing currents and turbulence throughout the lake, especially near the rune. Because of the higher water tables, other nearby places also become saturated with worst-case scenario: water, creating mud, swamps, flooding, and structural damage. More wetlands form. There are more places for mosquitoes to breed.
2) If there's significant evaporation: The air around the lake becomes more humid and it may rain more. This may cause more erosion in places that wouldn't have it normally. May cause occasional flash flooding if there's really thin valleys downwind. Plants will grow around the lake. Crocodiles or other animals may move in. There are more places for mosquitoes to breed.
3) If evaporation and ground seepage aren't enough to prevent water from forming rivers leaving the lake: A river will suddenly form, and several streams may form. Steady-state, it will have approximately the same flow rate as the rune. This will, initially, cause flooding downriver, and a lot of erosion as the water cascades downwards. Sandbanks will erode away and build up, and in the immediate future the river will likely change course several times until the erosion eventually slows. More plants will grow around the river. Crocodiles may decide to move in.

There will also be societal and economic effects. If the new lake can remain unaffected by contamination from the soil, parasites, and mosquitoes, it will make the people around it healthier. More plants (including fruit trees) will be grown in the areas around it. If it can remain free from corporations, it will be a great boon to the society. The new flooding, erosion, rivers, and wetlands will change what crops can be grown, what pathway you take to walk to religious services or work or friends' houses, and so on.
Plus, the sudden appearance of several lakes will immediately gather the attention of world news organizations, governments, and religious leaders. They will show up all over the news, and scientists will investigate them. Eventually, once they find a way around the crocodiles, they'll discover the runes on the lake floor.

Then, magic will be revealed to the non-wizarding world. The African wizards and witches will probably be pressured to reveal themselves. The North American Scourers will expand their influence across the world, especially to Africa, and begin public witch hunts. The wizarding community will declare open war on the witch-hunters. Magical attacks will be blamed on new bioweapons in the news, and positive relationships between nonmagical governments and magical governments will shatter. Wizarding governments will fracture. The source of the lake will eventually be traced back to Harry Potter and Hogwarts. Great Britain will be further isolated from the rest of the wizarding community, while Scourers attack everywhere else. Magical communities will blame the Great Britain wizards for these attacks. New groups similar to or worse than the Death Eaters will crop up. Due to decreased unity, magical beasts all over the world will be no longer hidden as well, will be spotted, and the wizards won't be capable of covering up their existence much longer. Great Britain wizards will be under attack by Scourers, Neo-Death Eaters, foreign wizards, and non-magical governments. J.K. Rowling will be forced to write a new Harry Potter universe movie that takes place in the post-Harry Potter apocalyptic future.
Crocodiles may take up residence.

[Brother Oni]

There are more places for mosquitoes to breed.

Which in turn will contribute to increased malaria spread. The water won't stay fresh for long in Africa's climate, which means all sorts of other water borne diseases and critters, leading to potential epidemics (or pandemics if you're really unlucky).

[Xuc Xac]

Harry Potter's runes will close Madagascar.

[factotum]

Honestly, I prefer it that way. Some authors really go deep when they world build, they feel like they have to explain everything in a logical system that makes perfect sense down to the last detail. I prefer "because magic" beyond a few details at most. Its magic, people!

Yet you're the one who came here and asked a question about how this purely magical set-up would affect the world's oceans? :smallconfused: Surely by what you just said, it shouldn't actually matter to you if the water comes from the oceans or is just spawned magically from thin air...

[Teddy]

It is worth raising the question of where the salt and other minerals that are removed from the sea water on transportation go. If it is left in the sea then the net effect is the same as more water evaporating fromt he sea and falling as rain on the and.
If the minerals are lost then (very very slowly) this will being to dilute the seas - but probably not in a way that will be noticed for centuries at least. Oddly removing the dissolved carbon dioxide in this fashion would reduce the problem of increasing sea acidity and be a useful source of atmospheric carbon capture (as it allows the sea to absorb more from the air).

Actually, we can go a little deeper here, because where in the ocean are the minerals dumped? Are they sprinkled fairy-dust style across the entire ocean, dilluting them to homeopathic concentrations, or are they dumped at a separate third rune, creating an oceanic mineral waste dump which rapidly would increase the local mineral contents to inhospitable levels? It wouldn't matter much on the global scale, but locally it would be catastrophic.

[ace rooster]

This is great:


The tiniest blue sphere is fresh water in lakes and rivers, Potter could double it and the effect on the big sphere would still be almost nothing. It is amazing how small all the water is compared to the Earth itself.

That doesn't take mantle water into account, and I believe the current thinking is that there is actually a lot of it (https://en.wikipedia.org/wiki/Water_distribution_on_Earth#Water_in_Earth.27s_man tle). Not strictly relevant, but thought you might be interested.


Yet you're the one who came here and asked a question about how this purely magical set-up would affect the world's oceans? :smallconfused: Surely by what you just said, it shouldn't actually matter to you if the water comes from the oceans or is just spawned magically from thin air...

I think the statement was that he doesn't question the 'how' of the particular magic bit, but was interested in how the non magic world reacts. Some details of the how are important in this case though, so do need cleared up.

It all depends on how various conservation rules are maintained, but even if they are not the impact would be slow. As has been pointed out, the quantities of water involved would actually be quite small, compared to the rest of the water cycle, so provided there are no effects that build up the impact would be difficult to percieve. For reference, we have put an extra 50% CO2 into the atmosphere and the impact of that is still difficult to tease from the general noise in the climate. A little water will have an effect, but it will be well hidden. You might find yourself creating a local brine pool in the ocean, but they happen anyway, so are not a problem.

As for people noticing it; if you put the runes directly in aquifers they would probably be hidden for a very long time. There would be the occasional muggle who does the sums and realises that this aquifer is impossible, but aquifer accounting is difficult anyway, so they will probably just assume that they have missed something. Run it few a few conflict zones and you introduce huge unknowns.

[Yora]

I see swamps being the main problem of the scenario. Putting the outlets in places where the water can form rivers would be a better idea if the magic pumps are meant to keep working forever. If they don't, lakes without regular water intake would evaporate after some time anyway. And be terribly dirty much earlier.

[snowblizz]

As for people noticing it; if you put the runes directly in aquifers they would probably be hidden for a very long time. There would be the occasional muggle who does the sums and realises that this aquifer is impossible, but aquifer accounting is difficult anyway, so they will probably just assume that they have missed something. Run it few a few conflict zones and you introduce huge unknowns.

For it to be a viable source of water for people, which was the point to help those dry areas, there'd need to be a lot of it and it would be noticeable. It's not about sums, it's about having rivers and lakes where there currently are none.

Ofc the most hilarious aspect would be ruining sensitive ecosystems with this abundance of water. Bet it would wipe out a bunch of endangered species.


But mostly I like the idea of it ending up promoting lots of crocodiles. Because the real world is complex and trying to be helpful in one part can have huge impacts on others. Can't just tinker in on end and it'll all work out, us humans have been doing a lot of that.
When someone talks about sucking water away, well that'll cause new currents, will the well-meaning but hydrologically inept wizards put it close to the gulfstream? Or the deep ocean conveyor belt or whatever it's called. There are lots of deep ocean currents that are very important for everything. Water isn't just water either. Desalinisation is just one part. Eg drinking destilled water isn't very good for you. Be hilarious if the magic rune did just that and ended up ultimately being dangerous. Someone should write that fanfic :smallbiggrin:.

[BlueHerring]

\Be hilarious if the magic rune did just that and ended up ultimately being dangerous. Someone should write that fanfic :smallbiggrin:.Harry Potter and the Arcane Desalination Plant does have a certain ring about it...

[Traab]

Alternatively, it could work like a positive displacement pump (constantly outputting the same volume). This also has precedence with magic, such as the Decanter of Endless Water which always outputs a set volume of water per round regardless of the pressure.

Then, what happens afterwards depends on the flow rate of the water, the soil composition, the geometry of the landscape, and so on:
1) If there's significant seeping into the ground: the land around the lake becomes muddy. The water table may rise. Crocodiles may move into this new mudhole. The lakewater becomes murky, because the constant high flow is causing currents and turbulence throughout the lake, especially near the rune. Because of the higher water tables, other nearby places also become saturated with worst-case scenario: water, creating mud, swamps, flooding, and structural damage. More wetlands form. There are more places for mosquitoes to breed.
2) If there's significant evaporation: The air around the lake becomes more humid and it may rain more. This may cause more erosion in places that wouldn't have it normally. May cause occasional flash flooding if there's really thin valleys downwind. Plants will grow around the lake. Crocodiles or other animals may move in. There are more places for mosquitoes to breed.
3) If evaporation and ground seepage aren't enough to prevent water from forming rivers leaving the lake: A river will suddenly form, and several streams may form. Steady-state, it will have approximately the same flow rate as the rune. This will, initially, cause flooding downriver, and a lot of erosion as the water cascades downwards. Sandbanks will erode away and build up, and in the immediate future the river will likely change course several times until the erosion eventually slows. More plants will grow around the river. Crocodiles may decide to move in.

There will also be societal and economic effects. If the new lake can remain unaffected by contamination from the soil, parasites, and mosquitoes, it will make the people around it healthier. More plants (including fruit trees) will be grown in the areas around it. If it can remain free from corporations, it will be a great boon to the society. The new flooding, erosion, rivers, and wetlands will change what crops can be grown, what pathway you take to walk to religious services or work or friends' houses, and so on.
Plus, the sudden appearance of several lakes will immediately gather the attention of world news organizations, governments, and religious leaders. They will show up all over the news, and scientists will investigate them. Eventually, once they find a way around the crocodiles, they'll discover the runes on the lake floor.

Then, magic will be revealed to the non-wizarding world. The African wizards and witches will probably be pressured to reveal themselves. The North American Scourers will expand their influence across the world, especially to Africa, and begin public witch hunts. The wizarding community will declare open war on the witch-hunters. Magical attacks will be blamed on new bioweapons in the news, and positive relationships between nonmagical governments and magical governments will shatter. Wizarding governments will fracture. The source of the lake will eventually be traced back to Harry Potter and Hogwarts. Great Britain will be further isolated from the rest of the wizarding community, while Scourers attack everywhere else. Magical communities will blame the Great Britain wizards for these attacks. New groups similar to or worse than the Death Eaters will crop up. Due to decreased unity, magical beasts all over the world will be no longer hidden as well, will be spotted, and the wizards won't be capable of covering up their existence much longer. Great Britain wizards will be under attack by Scourers, Neo-Death Eaters, foreign wizards, and non-magical governments. J.K. Rowling will be forced to write a new Harry Potter universe movie that takes place in the post-Harry Potter apocalyptic future.
Crocodiles may take up residence.

Heh, I like this. Just wanted to mention that according to the story, within a hundred years of roughly book 5, everyone born was magical so there wasnt really a hidden world anymore. He never mentioned the crocodiles though, so I can only assume the shame he feels for creating that plague keeps him from talking about it.

[halfeye]

drinking destilled water isn't very good for you.

Er,


The drinking of purified water as a replacement for drinking water has been both advocated and discouraged for health reasons. Purified water lacks minerals and ions such as calcium that play key roles in biological functions such as in nervous system homeostasis, and are normally found in potable water. The lack of naturally-occurring minerals in distilled water has raised some concerns.

...

The consumption of "hard" water (water with minerals) is associated with beneficial cardiovascular effects. As noted in the American Journal of Epidemiology, consumption of hard drinking water is negatively correlated with atherosclerotic heart disease.

https://en.wikipedia.org/wiki/Distilled_water

It's not that clearcut, some people would be worse off, but not everybody, and you'd have to be drinking it your whole life to notice any effects whatever.

[Brother Oni]

But mostly I like the idea of it ending up promoting lots of crocodiles. Because the real world is complex and trying to be helpful in one part can have huge impacts on others. Can't just tinker in on end and it'll all work out, us humans have been doing a lot of that.

While true, I'm far more worried about hippos who wander about on land from water source to water source, rather than crocodiles who tend to stick to the same place.
I'm not a animal expert, but I'm fairly sure the African crocodile is non-migratory.

Mosquitos are fairly wide ranging and need very little water to lay their eggs in - two tablespoons of stagnant water is enough, let alone an infinite water supply.


Eg drinking destilled water isn't very good for you.

As halfeye pointed out, just because distilled water isn't as good for you as 'normal' water, it doesn't mean it's harmful. Here's a SDS for purified USP grade water (http://www.aqualab.com/education/sds-usp-purified-water/) - note the complete lack of risk phrases and safety measures (I've seen old MSDSs where the medical treatment for getting water in the eye was to flush it out with running water :smallbiggrin:).

[factotum]

As halfeye pointed out, just because distilled water isn't as good for you as 'normal' water, it doesn't mean it's harmful.

Well, no more so than normal water, anyway...you can actually die from drinking too much of the stuff, after all. :smallwink:

[snowblizz]

While true, I'm far more worried about hippos who wander about on land from water source to water source, rather than crocodiles who tend to stick to the same place.
I'm not a animal expert, but I'm fairly sure the African crocodile is non-migratory.
During droughts and such the African crocodiles do move to find new water spots. Both the hippo/crocodile problem in Africa does come about because access to water is important and tend to encourage moving closer to it.


Mosquitos are fairly wide ranging and need very little water to lay their eggs in - two tablespoons of stagnant water is enough, let alone an infinite water supply.
This would be the biggest issue I'd agree with. I've seen it said that traditionally African vilalges weren't built away from water sources, purportedly for this very reason and that much of the tropical diseas issue is that modern habitation has moved closer to water, in part as something Europeans would naturally do since that's how we tended to live in Europe.



As halfeye pointed out, just because distilled water isn't as good for you as 'normal' water, it doesn't mean it's harmful. Here's a SDS for purified USP grade water (http://www.aqualab.com/education/sds-usp-purified-water/) - note the complete lack of risk phrases and safety measures (I've seen old MSDSs where the medical treatment for getting water in the eye was to flush it out with running water :smallbiggrin:).
I'll admit that "don't drink the destilled water" was something I was told in school by the chemistry teacher (she might also have been worried about her supply). As a half remembered "fact" I did actually try and google it first. A quick look suggested one shouldn't be drinking it.

[ace rooster]

During droughts and such the African crocodiles do move to find new water spots. Both the hippo/crocodile problem in Africa does come about because access to water is important and tend to encourage moving closer to it.


This would be the biggest issue I'd agree with. I've seen it said that traditionally African vilalges weren't built away from water sources, purportedly for this very reason and that much of the tropical diseas issue is that modern habitation has moved closer to water, in part as something Europeans would naturally do since that's how we tended to live in Europe.


I'll admit that "don't drink the destilled water" was something I was told in school by the chemistry teacher (she might also have been worried about her supply). As a half remembered "fact" I did actually try and google it first. A quick look suggested one shouldn't be drinking it.

I would guess that it is more a "don't drink anything in a chem lab; no, not even the water". There is no guarentee that nothing has spilled into it or you have picked up the wrong container, and it would be a dangerous bad habit. The correct response to "but it should be safe" is "shut up and do as you're told". :smalltongue: It is not a case of distilled water being dangerous, it is that anything in a lab should be considered dangerous, and kids are dumb.

[georgie_leech]

So... does the fanfic give a reason why they're taking water from the oceans instead of just making some from magic? Aguamenti comes to mind as a working baseline.

[Traab]

So... does the fanfic give a reason why they're taking water from the oceans instead of just making some from magic? Aguamenti comes to mind as a working baseline.

Well it would take an awful lot of wizards casting aguamenti spells to fill a lake and provide enough water for crops, livestock, humans, etc etc etc. And thats just for one village. Using runes is a permanent fix to the problem.

[Tvtyrant]

My biggest question is why you would dump the water on the ground instead of building a concrete lined reservoir first.

If the goal is to aridify the Sahara, then what you want is trees and light rain. Trees cool the soil, which causes more water retention, which causes more trees and lowers temperatures. Frequent light rains allow the soil to develop without becoming rancid with bacteria, and prevents disease from spreading.

If the goal is to make farming profitable, then you don't want to get rid of the desert. Deserts are often better for farming then other places (if you can get irrigation water) because insect populations don't reproduce naturally there and blights don't spread as easily (since there is dead rock between farms). For fragile crops they are optimal farming conditions, so what you want is to have a large covered reservoir and distribution pipes in place first, then fill it with your self-renewing water source. Since you are starting from scratch you could plausibly hollow out one of the Atlas Mountains and gravity run the water from the reservoir into the desert where the farms are meant to be, so you wouldn't even need pumps.

[Traab]

I would imagine the reason he didnt do anything you mentioned is because the author has no real knowledge of that sort of field so he just said, "Need water? Give them lakes!' And called it a done deal.

[Rockphed]

I would imagine the reason he didnt do anything you mentioned is because the author has no real knowledge of that sort of field so he just said, "Need water? Give them lakes!' And called it a done deal.

And then be confused by the main changes being an abundance of crocodiles, more mosquitoes, and several species going extinct.

[Yuki Akuma]

And then be confused by the main changes being an abundance of crocodiles, more mosquitoes, and several species going extinct.

We should change the collective noun for crocodiles to "an abundance of crocodiles".

[Rockphed]

We should change the collective noun for crocodiles to "an abundance of crocodiles".

That sounds like a good idea. Do you mind if I sig this?

[factotum]

If the goal is to make farming profitable, then you don't want to get rid of the desert.

You especially don't want to get rid of the Sahara, because (as I recall) nutrient-rich stuff blown across the Atlantic from there is one of the main reasons the Amazon rainforest exists.

[Yuki Akuma]

That sounds like a good idea. Do you mind if I sig this?

Why would I mind?

[Rockphed]

Why would I mind?

I don't know. I was trying to be polite.

[Yuki Akuma]

I don't know. I was trying to be polite.

Oh, no, I understand that it's considered proper etiquette to ask before quoting somebody in your signature - I was just answering with a variation "of course you can". :smalltongue:

[Tvtyrant]

You especially don't want to get rid of the Sahara, because (as I recall) nutrient-rich stuff blown across the Atlantic from there is one of the main reasons the Amazon rainforest exists.

It would also change the climate of the Mediterranean by eliminating the sirocco. I don't know what the exact effects would be, but they would probably be disastrous.

[halfeye]

It would also change the climate of the Mediterranean by eliminating the sirocco. I don't know what the exact effects would be, but they would probably be disastrous.

Yeah, but the interesting is would it be less disasterous than the existence and expansion of the Sahara.