Lake Poopó, Bolivia's second largest lake, has vanished | Hacker News Reader

Lake Poopó, Bolivia's second largest lake, has vanished

esa.int

145 pointsfinid42 comments

"The three 100-m resolution Proba-V images shown here were acquired on 27 April 2014, 20 July 2015 and 22 January 2016 respectively."

"But the lake’s shallow nature, with an average depth of just 3 m, coupled with its arid highland surroundings, means that it is very sensitive to fluctuations in climate."

These quotes leave me wondering; why did they chose to take these images in vastly different times of year?

It may correspond to availability of the satellite to take the photos of the area.

First the satellite has to be over the area. Second the satellite has to be free from other tasks to take photos of the area. From Wikipedia, the satellite's mission involves:

Proba-V will support applications such as land use, worldwide vegetation classification, crop monitoring, famine prediction, food security, disaster monitoring and biosphere studies.

Taking photos of a single lake in Bolivia may not be high on that list of priorities.

Interesting speculations, but that's not how these environmental monitoring satellites work. They are set up to get global coverage with this instrument every 5 days. The orbit is chosen so that this happens, to enable long-term time series of vegetation, land cover, etc., as you note.

It's a successor to other satellites like SPOT, and a competitor/complement to NASA satellites like MODIS.

They appear to have, in essence, two imaging modes. They are showing the higher-resolution-mode, with 100 meter pixels, which are made every 5 days. (They get global coverage every 5 days.) I'll bet there are very few clouds there, so almost all the images (~66 per year) will be OK.

It turns out (http://www.tandfonline.com/doi/pdf/10.1623/hysj.51.1.98) that the lake is fed by a river which is in turn fed by Lake Titicaca (made famous by Beavis and Butthead). Almost all rain there falls from December to March, so the first two images would be fairly "wet" while the last one (from January) might be rather "dry". Of course, in December 2015, the lake totally dried up.

Besides the climate sensitivity, they also have a water management problem, because the level in the downstream Popoo is controlled somewhat by releases from Titicaca.

One more thing: this set of visual images finds lake extent by measuring the retreat of the shoreline. Another approach is to use radar to find the elevation of water bodies, directly, to high accuracy. That should happen in a couple of years when SWOT launches (https://en.wikipedia.org/wiki/Surface_Water_Ocean_Topography...).

Same thing happened to the Aral Sea: https://en.wikipedia.org/wiki/Aral_Sea

I went there (Aralsk, specifically) four years back, while en route to shymkent from aktobe. It's a sad, sad place. Photos don't do it justice - you drive for hours through barren desert, passing next to nothing, and then you reach Aralsk - a nothing harbour city in the middle of nothing, with a tide that went out to never return. Everything is dilapidated, dusty, everyone is old, the smell of diesel mixed with shit and mud is overpowering - the sea looks dry, but under a thin crust is meters of gloopy dumped oil and sewage. Learned that the hard way.

It used to be a bustling place, full of greenery, and the desert around it was green - but the Soviets drained it from the Uzbek side, and whether it can ever be refilled more rapidly than it evaporates is anyone's guess.

Central kaz could have been a place. Instead, it's nothing, and probably will remain such.

Easy to go "oh it's just a lake", but it turns out humans need water.

Interestingly, the Soviets planned to take Siberian rivers that drain "uselessly" into the Arctic sea and divert them southwards towards Kazakhstan and into the Aral sea.

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

No the same thing did not happen to the Aral Sea. What happened to the Aral sea was far far worse and far far more of our fault (humans).

That was far far more the Soviets' fault, not "our" fault.

Ah! That makes it much better. At least I'm not to blame. (Sarcasm)

I think "we"(humans) need to take more responsibility as a whole. If one of the people in your life boat is drilling a whole in the bottom in the middle of the sea, being able to place blame doesn't matter so much. "We" are all going down if "we" can't do something about it.

Subsuming responsibility for things that one could have prevented is one thing; accepting responsibility for something that nothing short of war could have prevented is another.

And the US eliminated the largest freshwater lake West of the Mississippi [1].

[1] (largest by area) https://en.wikipedia.org/wiki/Tulare_Lake

A. Whataboutism is lame B. The Aral Sea was 10x larger [1] C. I do appreciate the irony of A D. the scale of both is mindblowing, so I upvoted you

[1] https://en.wikipedia.org/wiki/Aral_Sea

Sorry: I meant that as a response to the notion that the Soviets made a unique error with the Aral (hence the "don't blame us" stated in the parent) rather than being a common symptom of water diversion worldwide. It was not meant as to be a whataboutism, which is an awesome word for bad moral equivalence. I am so stealing that.

Whataboutism is lame when used to excuse a behavior, but completely valid when used to rebut accusations of unique malfeasance. There is a big difference between something being your problem vs our problem.

Wikipedia is wrong there. It lists a maximum surface area of 1,780 km^2 (690 sq mi) for Tulare Lake, while Lake Iliamna in Alaska is 2,622 km^2 (1,012.5 sq mi).

We're all humans, and we're all responsible for the Earth.

You are right. That said, diversion of water for agriculture is also a confounding factor in the case of Lake Poopó.

TLDR;

The lake evaporated in span of 2 years. It's a shallow lake only 3m deep and this has happened multiple times, most recently in 1990s. The article looks more like an ad for satellite data exploration.

I was thinking the same thing. Tons of satellite pictures, no in depth information about the actual problem.

Hard to find a problem where there isn't one, it is a thing that happened, that has happened before, in one of the driest regions in the planet.

/thread

Thanks!

Nasa's earth observatory has good very high res images/ some analysis of the lake Poopó , with and without water.

http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=...

they have some images hand shot from the space station too (2005 lower res):

http://earthobservatory.nasa.gov/IOTD/view.php?id=6494

"Water levels in Lake Poopó are important because the lake is one of South America’s largest salt-water lakes, making it a prime stop for migratory birds, including flamingoes. "

There has been a drought in the Western US too. Snowpack in sierra nevada.

http://earthobservatory.nasa.gov/IOTD/view.php?id=85632

I really like the earth observatory.

It may seem weird, but lakes that come and go are a thing. Here's one in Australia that drained in the 1990s and is now making a comeback:

https://en.wikipedia.org/wiki/Lake_George_(New_South_Wales)

Does this differ significantly from previously generated salt flats in the area? The article didn't seem to address arguably the more famous one in the area, Uyuni. (Which I recall reading up on when I played World of Warcraft and got sidetracked reading about salt flats on Wikipedia for.... too long)

If this happens fairly often (within the last 30 years, according to the article), then how was the lake stocked with fish for local fishermen to have been making a livelihood on in the first place?

Um, the fishermen stocked it. Lakes near any significant human population are stocked or they don't have fish.

Sometimes birds transfer fish eggs from one lake to another. Or fish travel between lakes during flooding.

I guess Quantum of Solace wasn't so far-fetched!

Honestly, I thought the villainous plot in Quantum of Solace was a little too realistic. Seizing control of a developing country's water supply? Isn't that a bit too old-hat and run-of-the-mill for the world's greatest criminal organization? Hell, if they were an American or British company, the CIA and MI6 would probably be helping them.

"There is no such thing as climate change."

Not to argue, but the article does say this isn't the first time the lake has disappeared. Wikipedia also adds that "The time period between 1975 and 1992 is the longest period in recent times with a continuous existence of a water body."

https://en.wikipedia.org/wiki/Lake_Poop%C3%B3

edit: the article's title is actually, "Proba-V eyes Bolivia’s vanishing lake" which is actually decent in that it seems to be trying to describe that the lake "vanishes" from time-to-time and that Proba-V is showing some views of it.

And at 3,686m about 12000' that wouldn't help evaporation either.

No one denies that climates change.

Some of us just reject the idea of natural teleology.

"Climate" is a term of observation for the apparent cyclic and geographical stability of air, water and temperature variations; and has been fluxing through time and across the globe since the Eoarchean due to life, mankind, and other non-linear inputs.

For values of "some" that included the overwhelming majority of those who have looked at the data scientifically, and excludes a large swath of people who have something to lose from the implications. Funny, that.

For salt lakes it is quite common to dry out sometimes. Besides changing river paths, excessive under ground water use and dams are more likely effecting them rather than global warming.

Climate change can happen independent of man's actions. The disagreement that separates many is how much effect does man have on climate, can it accurately be measured, and how much effect can man have on it; different from first case.

cherry picking by either side only identifies those who don't want to participate in the discussion

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