Thread: flooding valleys

Would you tell me what flooding valleys mens? and why flooding valleys are bad things like cutting trees?



A IT is an unquestioned principle that has dominated international thinking for decades: we live in an overcrowded world teeming with billions of humans who are destined to suffocate our cities and squeeze our planet of its precious resources. Our species is inexorably wrecking Earth: flooding valleys, cutting down forests and destroying the habitats of animals and plants faster than scientists can classify them.


Thanks in advance

Not sure what you mean by "flooding valleys". Do you have an example?

They are probably referring to building hydroelectric dams.

Ah, so something like the Three Gorges Dam?

If that's the case, my answer would be that it simply depends upon the situation. Cutting down trees or flooding an area doesn't have to be a bad thing. It is dependent upon the natural state of the area.

Any time a dam Is built It does many harmful things like displacing humans that live near the river, not allowing fish to travel where they want and disrupts the natural cycle of things that lived and used the river.

I would tend to agree that dams are often ecological nightmares.

Originally Posted by cosmictraveler

Any time a dam Is built It does many harmful things like displacing humans that live near the river, not allowing fish to travel where they want and disrupts the natural cycle of things that lived and used the river.

Agreed. It also does beneficial things (for people) like reducing flooding, ensuring a safe water supply and generating relatively clean energy. As always the good has to be balanced with the bad.

River valleys usually contain productive farmland. Flooding river valleys makes that land unavailable for crop production.
The loss of the food production from that land has to be balanced by other benefits like power production, irrigation, or some other kind of use for the water in the reservoir above the dam.

Originally Posted by dan hunter

River valleys usually contain productive farmland. Flooding river valleys makes that land unavailable for crop production.
The loss of the food production from that land has to be balanced by other benefits like power production, irrigation, or some other kind of use for the water in the reservoir above the dam.

What was the farmland before it was farmland? Probably woods. And since river valleys tend to flood, it might not be the best place to put a subdivsion anyway. To me it seems like one of the least damaging changes to the environment in order to generate energy, and probably creates some new habitats for animals and birds as well.

Funny Isn't It that Native Americans lived without any form of power generation for at least 40,000 In North America.

Originally Posted by cosmictraveler

Funny Isn't It that Native Americans lived without any form of power generation for at least 40,000 In North America.

Agreed, at least when it comes to electrical power.

Do you use electric power? I suspect the answer is "yes" given that you are posting on the Internet with a computer. Most people have desires similar to yours - which is why we won't return to using zero electrical power any time soon.

Originally Posted by cosmictraveler

Funny Isn't It that Native Americans lived without any form of power generation for at least 40,000 In North America.

Not really if you consider world history. Power generation is a very recent event in the archeological record.

Do you use electric power? I suspect the answer is "yes" given that you are posting on the Internet with a computer. Most people have desires similar to yours - which is why we won't return to using zero electrical power any time soon.

Yes I use electricity now but can and have, while camping, learned that I do not need it to survive. That is how those humans that lived before electricity survived and they did OK.

Originally Posted by cosmictraveler

Yes I use electricity now but can and have, while camping, learned that I do not need it to survive. That is how those humans that lived before electricity survived and they did OK.

Sure, you can live without electricity. Also without vaccines, dental care, safe water supplies, basic sanitation, medical care, heat, pesticides, agriculture, transportation, shelter, a justice system etc etc. It's just not very pleasant and you probably won't live as long. Thus the trick is to manage to provide what people desire without harming the environment too much in the process.

Native Americans lived In North America for 40,000 years and they did not abuse the land but rather respected it very much. They had their warriors, chiefs, herbs for medicine and many other things that made their lives good enough to live and multiply over time. If they were not doing a good enough job of living they would not have grown into the millions that once lived in North America. As for dying well their lives were shorter which helped them to not have as many people living to support. Less people , less overcrowding and better living conditions for the rest of the tribes.

Originally Posted by cosmictraveler

Native Americans lived In North America for 40,000 years and they did not abuse the land but rather respected it very much. They....

That is a nice piece of modern mythology but it is not true.
If you look again at native hunting and agricultural prctices in the Americas you find a lot of very destructive methods. Everything from burning areas of land to grow corn on to running entire herds of bison over a cliff so they could butcher out the prime cuts and leave the rest to rot.
About the only things that kept the natives from entirely destroying their environment was the fact that there were so few of them and they lacked modern technology. The result was that most of the time the natural environment could recover. Even at that the native civilizations still managed to force quite a few large animals into extinction long before the Europeans showed up and helped them to be more efficient.

Originally Posted by cosmictraveler

Native Americans lived In North America for 40,000 years and they did not abuse the land but rather respected it very much.

Have to agree with Dan on this one. The Amerindians are a large focus of my work (I will be spending the summer at Angel Mounds in Indiana on an NSF grant).

You might enjoy reading this: The Pristine Myth: The Landscape of the

I copied that link as an open doc file Flick.
Thank you for it because I hadn't seen that one before.

Originally Posted by dan hunter

River valleys usually contain productive farmland. Flooding river valleys makes that land unavailable for crop production.

Not really and it depends on how regular that flooding is. Egypt remained a dominant power for thousands of years specifically because of the annual lower Nile flooding that replaced lost silt with fertile silt from the upper valley (and spurred cultural progress in land laws, surveying and geometry). Every year as the water receded they'd reestablish old land boundaries, and plant a new season of crops.

The result was that most of the time the natural environment could recover.

Which they probably knew would happen. They were very intelligent humans as they left the Earth non polluted by chemicals, trash and other nefarious stuff.

Even at that the native civilizations still managed to force quite a few large animals into extinction long before the Europeans showed up and helped them to be more efficient.

Could you please say which animals they made extinct? Don't forget there were ice ages when they lived in North America.

Originally Posted by cosmictraveler

Which they probably knew would happen. They were very intelligent humans as they left the Earth non polluted by chemicals, trash and other nefarious stuff.

I don't know that I would say that. There was evidence of accidental fires raging out of control due to Amerindians. They were no more or less educated about natural ecology than any other peoples. They were just as guilty of negatively impacting the environment as anyone else at the time. However, they lacked the technology to make such impacts on the scale of the more advanced European settlers. If the suggestion is that the American Indians were more environmentally conscious than other peoples, the evidence needs to support that claim. As it stands, the evidence does not.

Basically, the idea that the Amerindians knew how to treat the planet well came from the settlers having their homeland's ecological problems put into perspective by a land which just had not been affected to the same degree as theirs.

Originally Posted by cosmictraveler

Could you please say which animals they made extinct? Don't forget there were ice ages when they lived in North America.

There is a well-documented chronology of human arrival and megafauna extinctions. Again, there isn't any evidence to suggest that the Amerindians were careful not to damage the ability of a species to continue. There is evidence that they set mass fires to flush game out of forested areas so they could kill what they needed. This was a destructive practice.

[QUOTE=Lynx_Fox;529158][QUOTE=dan hunter;527798]River valleys usually contain productive farmland. Flooding river valleys makes that land unavailable for crop production.

Not really and it depends on how regular that flooding is. Egypt remained a dominant power for thousands of years specifically because of the annual lower Nile flooding that replaced lost silt with fertile silt from the upper valley (and spurred cultural progress in land laws, surveying and geometry). Every year as the water receded they'd reestablish old land boundaries, and plant a new season of crops.

The original context of the OP matters.
It is very likely from the way the question is worded that she is being asked about permanent flooding.
When I said most of the river valleys that were dammed had usable farmland it is true.
In northern Ontario, Quebec and in BC some of the rivers never had agricultural land in them. Most of those dams are fairly small and are on small rivers in the precambrian shield. These types of dams are still fairly disruptive and change the local ecology of the river, but the ecological factors were covered by other posters so I was not commenting on that.

We also have dams like the Moses-Saunders Power Dam on the St Lawrence River at Cornwall which was a joint project between Canada and USA. It did take away good farmland and forced people to relocate. There is even an underwater ghost town that scuba divers visit.

DianeG commented in post #9 that before it was farmland the land behind most dams were forest and that the dams are the least damaging way to produce power. I saw nothing in her comment to disagree with, but it really had no bearing on what I had said either.

Your choice of the Aswan Dam and its effects on the Lower Nile is good though because it illustrates the damage dams can cause to agricultural lands downstream. Soil fertility in the area of Egypt is generally low. Not only are the soils, such as they are, depleted of nutrients the parent rocks are depleted as well. The Nile not only provided irrigation water, the annual flood brought the silts from more fertile rock formations and deposited them as silt. Agriculture along the Lower Nile was being steadily fed with clay minerals that included elements like potassium from the breakdown of feldspars.
The Aswan cut not just the flooding, it trapped all those clay minerals behind it as siltation too. Soil fertility in the Lower Nile dropped and has not recovered. Artificial fertilizers are needed now.
Taking the effects farther downstream you also sea the shrinking of the Nile Delta with reduced fertility in the Mediterranean Sea near to it. So not only reduced food yields from the land without artificial fertilizers but reduced returns from fishing too.
I would agree the production levels became more stable for the agricluture though because without the variability in the annual flood drought seasons and extreme flood seasons no longer happen.

I can remember there being active debates at the time of the Aswan Dam (and I was just a teenage kid then) about what the effects would be and whether the electricity would be worth the losses. Obviously power generation and modernization won. Cotton production as an export crop was a factor too because they needed water for irrigation.

Flick mentioned the Three Gorges Dam in China and his comment is true.

There are balances to consider in every decision humans make and in the case of the Aswan and Three Gorges I think the benefits largely outweighed the cost incurred, but the costs still exist and still have to be considered.

Originally Posted by dan hunter

The original context of the OP matters.

The context was garbage and wasted several post trying to figure out even what it meant.

I can remember there being active debates at the time of the Aswan Dam (and I was just a little kid then) about what the effects would be and whether the electicity would be worth the losses. Obviously power generation and modernization won.

Not obvious at all. They traded short term gain (the entire system will last perhaps a century--so typical) for massive ecological devastation to the Mediterranean ecosystem, a retreating coastline, sinking delta and agriculture which is now dependent on unsustainable fossil fuel based fertilization.

Originally Posted by Lynx_Fox

Not obvious at all. They traded short term gain (the entire system will last perhaps a century--so typical) for massive ecological devastation to the Mediterranean ecosystem, a retreating coastline, sinking delta and agriculture which is now dependent on unsustainable fossil fuel based fertilization.

They built the dam, seems pretty obvious which considerations won.
5, 10, 15, and 20 year plans are usually thought of as long term planning, and even then people tend to be too busy trying to avoid unexpected immediate problems to worry about the long term plan.
I don't think anybody thought much about ever running out of oil in the 60s when the decision was made to build the Great Aswan. I doubt if anybody thought about oil scarcity much at all until after the 1970s oil shocks. Even after the OPEC price shocks it was believed it was an artificial shortage and only an attempted market manipulation.

It is very tempting to look at history and assume the people then should be aware of what seems obvious to us now, but they only had the knowledge that was current in their time.

Originally Posted by cosmictraveler

Native Americans lived In North America for 40,000 years and they did not abuse the land but rather respected it very much. They had their warriors, chiefs, herbs for medicine and many other things that made their lives good enough to live and multiply over time. If they were not doing a good enough job of living they would not have grown into the millions that once lived in North America.

They were certainly doing a good enough job to survive. But again, I suspect you would prefer a different style of living than they had - and that means you (and people like you and me) take more energy than a typical native American. Thus our tradeoffs over water, agriculture, energy, transportation, medical care etc.

As for dying well their lives were shorter which helped them to not have as many people living to support. Less people , less overcrowding and better living conditions for the rest of the tribes.

Well, given that they killed each other quite regularly (inter-tribal warfare over land and resources was endemic) that didn't work in most places.

Originally Posted by dan hunter

Originally Posted by Lynx_Fox

Not obvious at all. They traded short term gain (the entire system will last perhaps a century--so typical) for massive ecological devastation to the Mediterranean ecosystem, a retreating coastline, sinking delta and agriculture which is now dependent on unsustainable fossil fuel based fertilization.

They built the dam, seems pretty obvious which considerations won.
5, 10, 15, and 20 year plans are usually thought of as long term planning,

Because Western societies, from which many planning and business models are copied in other places, are extremely short sighted.

Originally Posted by Lynx_Fox

Because Western societies, from which many planning and business models are copied in other places, are extremely short sighted.

Not just western. Short term planning is pandemic. Even the Great Wall of China was built by short term planning. The thing is things change over time and the changes are happening fast enough that longer term planning is irrelevant.

Originally Posted by dan hunter

The thing is things change over time and the changes are happening fast enough that longer term planning is irrelevant.

I'm going to need an example of this as I don't understand the comment.

Environmental impact planning doesn't change at the basic level. It will never be "okay" to flood out entire ecosystems so long-term planning is very important.

Originally Posted by Flick Montana

Originally Posted by dan hunter

The thing is things change over time and the changes are happening fast enough that longer term planning is irrelevant.

I'm going to need an example of this as I don't understand the comment.

Environmental impact planning doesn't change at the basic level. It will never be "okay" to flood out entire ecosystems so long-term planning is very important.

Sorry, once again I thought I was saying something extremely obvious and only worth a brief general comment.
OK, even your example, environmental impact planning is a fairly recent change.
Other than counting how many people would be forced to move and how much compensation they deservd very little of it was ever done before the 1980s. The idea that you should prepare an environmental impact statement and submit it to your local environmental assesment board was completely unheard of until the late 1980s.
In he 1990s environmental assesments were including plant and animal habitat loss with a high degree of emphasis on endangered species.
Not only was the beginning of Environmental planning a change, it never stopped changing once it was in place.

Whatever, I was refering more to things like international markets, population fluctuations, wars, revolutions, technological changes,etc.

If I am still being confusing tell me a bit more about just what you do not understand and I will try to clarify my comment a bit better.