Guest no schist Sherlock by David Middleton
From the AGU’s “bleeding obvious” files…
Where Did All the Free-Flowing Rivers Go?A map of the world’s free-flowing rivers shows a shrinking number can still meander as they please. New plans for hydropower will further constrain flow.
By Jenessa Duncombe
Giant catfish once swam in the golden-brown waters of the Mekong River near the Thai village of Sob Ruak. But since the Chinese government built hydropower dams upstream, the waters now drop too low for the catfish to lay their eggs. The loss of habitat for the catfish is just one of many stressors the increasingly developed river faces.A new study released 8 May in the journal Nature suggests that the Mekong’s plight is not unique: Humans have significantly impacted the majority of the world’s 242 longest rivers. Just one third of long rivers still flow freely throughout their entire length, and the most untouched rivers exist far from population hubs in the Arctic, the Amazon River Basin, and the Congo River Basin.
[…]
“This study is not meant to be a study that says ‘stop any kind of development,’” Bernhard Lehner, an associate professor in the Department of Geography at McGill University in Montreal, Canada, and one of the first authors on the study, told Eos. “But it’s meant to find smart solutions.”
[…]
The analysis revealed not only that most of the world’s longest rivers are no longer free-flowing but also that dams are the overwhelming cause.
[…]
“We always come back to dams as being the main culprit in all this,” Lehner said.
Dams stop species from migrating upstream, and they also trap sediment, preventing it from flowing down the river.
[…]
Murky Waters
Although dams fragment a river and cause a litany of downstream damages, they also provide a source of renewable energy. There are increasingly urgent calls worldwide for lowering greenhouse gas emissions, and hydropower dams are one answer.
Climate change driven by greenhouse gas emissions harms rivers as well: Hotter air temperatures warm river waters and decrease the amount of dissolved oxygen they can hold. Restricting the free flow of rivers by installing hydropower dams will hurt the ecosystem further, according to the new study.
“While we try to counter climate change, it makes the situation in rivers worse for ecology,” Lehner noted. “This is the conundrum in this whole story.”
Lehner hopes that the new data set, which is available with its source code for free, will give planners a resource to scrutinize the full effects of river management infrastructure.
[…]
Eos
“This study is not meant to be a study that says ‘stop any kind of development… But it’s meant to find smart solutions… We always come back to dams as being the main culprit in all this… While we try to counter climate change, it makes the situation in rivers worse for ecology… This is the conundrum in this whole story.”
Ummm yeah, have you thought about just going with natural gas and nuclear power for new power plants? And… Maybe trying to capture as much CO2 as possible from coal-fired plants and using it for enhanced oil recovery?
I think we can defeat the Green Mafia the same way Captain James T. Kirk defeated Harry Mudd’s androids…
The Eos article did feature a really neat map…
A map of global rivers’ free-flowing status. Credit: Grill et al., 2019, https://doi.org/10.1038/s41586-019-1111-9
Citation: Duncombe, J. (2019), Where did all the free-flowing rivers go?, Eos, 100,https://doi.org/10.1029/2019EO123209. Published on 08 May 2019.
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I took a guided tour of the Bonneville Dam on the Columbia river in
2008. A greenie asked the Ranger when the dam was scheduled to be
removed.
The Ranger seemed to indicate that there was a schedule for all the
dams on the Columbia to be removed but that he could not share the
schedule.
If anyone knows that the deep state had a plan to make the Columbia
a free river again, I would like the report.
I lived just off the Columbia in the ’40s and ’50s. The Columbia in spring
flood was awesome.
I told the Ranger that I didn’t think that the massive economic benefits
of flood control, electric generation, and massive amount of fertile land
would be allowed to be lost to the warped sense of order of greens.
Think of the devastation to the beer industry, the loss of all those hops
grown in eastern Oregon.
It won’t happen-the ranger was just trying to keep the watermelon happy. If the dams were to be removed, the cities of Portland and Vancouver would be flooded on an annual basis, Eastern Oregon and Washington would return to desert, Idaho’s agriculture (including it’s famous potatoes) would be history, Microsoft, Boeing, Amazon, Intel and a score of other major business would have to leave. To remove the dams would return the Pacific Northwest to a wilderness. Remember, the greens don’t even want a hunting and fishing economy. If they got their way with everything they are against we would back to the Stone Age-literally.
This may have been asked and answered, but I’ve never understood why something can’t be done to enable fish migration over dams. I know there are fish ladders, but apparently they don’t do the trick, or migration interference wouldn’t still be an issue. Surely an engineering solution would require minimal technological expertise.
Fish ladders hyper-oxygenate the water, killing or weaken a substantial
percentage of the migrating fish.
The best, but very expensive method I observed, was a very large crane
with a large bucket dipping into the migrating fish and gently depositing
up or down stream, depending on the season. This was done from the
time flow was impeded until the ladders were finished.