Sr. Zonules

To Mod: I'm not quite sure where this goes... maybe it belongs in S&S?

The other day I was listening in to a conversation at school (college) about the new dam that is being built in China, known as the Three Gorges Campaign. Anyway, one of the gals was talking about how horrible she thought the project was, based on several factors. Among these factors included the destruction of historical cities (thousands of years old??), the environmental impact of the dam (fish impedence, pollution (from construction), flooding, etc...) and that it would somehow (due to the displacement of water) disrupt the earth's axis. I was just wondering about the validity of these factors, and also (the reason why I put this thread here): is it OK to destroy old cities (if that is indeed a factor) to build new big-business? I generally say that it is OK, and I really feel like there's something weird / wrong about this gal's arguements, but I haven't been able to put my finger on it.

-Z

Pyrrho

Old cities often have historical value. If you don't care about history or what happened in the past, then this will not matter to you.

Also, if the cities have people living in them, then the dam will involve throwing people out of their homes, and confiscating their land. If you don't care about other people, and if you don't live in one of these cities yourself, then this will not matter to you.

As for environmental factors, new projects, particularly large ones, invariably do damage to the environment. Typically, whether someone is concerned about such damage depends on how much damage will be done, and what kind of damage, for which one must consider the specific things that will be destroyed, and whether or not such things exist elsewhere in great quantity. Again, you may not care about these matters, as you may not care about the environment.

As for the disruption of the earth's axis, that just sounds silly. (And, as a side comment, I found nothing about such a claim at the site to which you provided a link. If you have found something about this claim, please provide a link to it specifically. They do, however, have more to say about how the project is being done, and about human rights violations that are occurring. Such an argument, of course, does not show that the dam should not be built, only that the way that it is all being handled is not satisfactory.)

sourdough

this may be silly question ,but wouldn't the weight of the water affect the tecktonic plates underneath it and perhaps cause earthquakes?

Bill Snedden

I agree, off to S&S...

ps418

On the other side of the equation, how many people will benefit from the flood control of the Yangtze and the power produced by the dam (assuming the dam functions as advertised)? The 1998 Yangtze flood killed ~1300 people, made about 13 million people homeless, and caused economic damage of 20 billion dollars. Source

The water weight would not affect tectonic plates, but the filling of the resevoir behind the dam will definitely cause minor, local earthquakes and cause displacement along local faults. This happened behind Boulder Dam as Lake Mead filled behind it.

Patrick

Sr. Zonules

thanks patrick for the information. I always enjoy your responses. I'll have to check into this stuff a little later, after I finish my big project for biology. I am already excited though.

-Z

Gurdur

While the "affecting the Earth's axis" sounds like whacko looney time at first hearing, I will add that someone came up with this idea a few years ago, IIRC:

there are seven mega-dams in the Northern Hemsiphere with huge amounts of stored water that would otherwise flow to the sea and even out, and only two in the Southern hemisphere; therefore the huge additional lop-sided weight might affect the Earth's angle of rotation.

Don't bother flaming me for this; I merely report my half-memories of the mooted idea, I'm not pushing it.

elwoodblues

They might seem like vast amounts of weight to us, but in the scheme of the planet, it's tiny.

In addition, it feels like you're thinking about this wrong. I don't think gravity and rotating bodies work like that. Maybe someone else more familiar with the forces at work could pin this down to words.

Gurdur

No, it isn't.
Elwood, for goodness' sakes, go back and read what I wrote --- carefully.

OF COURSE, I COULD WRITE IT AGAIN, AND THIS TIME IN GREAT BIG RED LETTERS, THAT I WAS ONLY REPORTING THE IDEA, NOT PUSHING IT.

Or I could simply refer you politely back to my post ?

SULPHUR

They may cause problems if built in unstable areas but considering total crustal mass are insignificant. Just as the earth corrected for the ice ages the mass of water is insignificant.