
The scramble for sand is destroying the Mekong - pseudolus
https://www.bbc.com/news/business-50629100
======
latchkey
It isn't just sand. What is also happening is that China is building an
endless supply of hydrodam's along the Mekong (and other) rivers in Cambodia,
Laos and Vietnam. I've seen this first hand. This is screwing up the natural
flow, which is also affecting the sand 'production'.

This is all part of China taking over the whole region by providing power and
thus building a silkroad all the way to Sihanoukville, where they ship goods
south to Jakarta and west to Africa. Google what is happening there and you'll
see it.

This is me driving a motorbike across what is now a totally dry riverbed in
northern VN all because of unseasonably dry weather and hydrodam's upstream...
[https://imgur.com/a/7hfxRD7](https://imgur.com/a/7hfxRD7)

~~~
riffraff
I just learned about this last week watching "Seamen" on prime video[0]. It is
pretty terrifying.

But one thing I don't get is: once the dam is built and filled up, shouldn't
the water be back to flow regularly? It seems the dam should only act as a
buffer, but not cause a dramatic decrease in water flow. Is it because
evaporation at the water basin is much higher than on the river?

[0] an episode of the show called "The Grand Tour" where they usually drive
cars, but here they drove boats on the Mekong.

~~~
latchkey
Persistent unseasonably dry weather. There is no water, even at the top. A lot
of the water held at the dams is also diverted to local farms so it never
continues 'down the hill'...

Then what happens is that the water is further away (lower) and people build
houses closer... a big rain comes in and wipes away the houses. That is why in
the wet season, you see stories in the news about all the landslides... which
are a combination of building and deforestation for farming.

Epic levels of mismanagement and no education...

~~~
Gibbon1
I don't know how it works south east asia. But I've read that 10% of the water
that flows into Lake Powell is lost to evaporation.

~~~
latchkey
Humidity is already higher here, so probably less lost. Also factor in the
rain bringing it back again.

Lake Powell (which I've also been to) is HUUUUGEEE. The 'lakes' created from
hydrodam's off the Mekong are tiny in comparison.

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spodek
Once you see environmental problems as, despite each being unique, mostly
arising from overpopulation, you can't help substitute for the proximal cause
"overpopulation".

> The scramble for sand is destroying the Mekong

Becomes

> Overpopulation is destroying the Mekong

You might add "one way is the scramble for sand" though there are plenty
others.

Learning about various nations' successful, noncoercive programs to lower
birthrate that are as far from China's policy, forced abortions, or eugenics
as day from night, and that increased prosperity and happiness, leads you to
embrace such programs. The book _Countdown_ by Alan Weiss
[https://www.amazon.com/Countdown-Last-Best-Future-
Earth/dp/0...](https://www.amazon.com/Countdown-Last-Best-Future-
Earth/dp/0316097756) describes several such programs, including in Thailand,
Iran, Costa Rica, Mexico, and others.

The most effective solution to the Mekong situation, however partial, is
contraception and family planning education.

~~~
throwawayhhakdl
They’re not though. That’s a vast oversimplification. There are many
individuals who consume and pollute 1000x more than others. You could probably
add a few zeroes there and still be accurate.

Many problems would continue to exist and continue to get worse if local
populations were to start decreasing over time.

------
lainga
_Desert sand is too smooth to bind to make concrete, so sand is taken from
river beds such as the Mekong_

That's really interesting, but makes sense. The sand in most deserts has been
blowing around for millennia (or longer), and so would be extremely smoothed-
off. Sand in the Mekong is relatively young, and not that far removed from
when it was a rough chip off a rock upstream. The difference here is called
sediment maturity [] IIRC from first-year geology.

But can anyone answer: why is mature, rounded, fine sand not suitable for
binding concrete or for glassmaking? And how fine can the sand be -- wouldn't
extremely fine grains classify as clays instead?

[]
[https://en.wikipedia.org/wiki/Maturity_(sedimentology)](https://en.wikipedia.org/wiki/Maturity_\(sedimentology\))

~~~
lightedman
"But can anyone answer: why is mature, rounded, fine sand not suitable for
binding concrete or for glassmaking?"

It's the jagged edges on 'fresh' sand that gives the mix strength. Smooth sand
is fine for glassmaking (something I do along with metal and jewelry work) but
horrible for construction, as it doesn't grip into the binding agent as well,
and any serious load makes it turn straight into dust.

The sand can be as fine as possible, as long as it isn't rounded, and still be
useful for construction work.

~~~
abduhl
I'm not a concrete mix design expert by any means, but I disagree with this
post on a few levels. Concrete strength is derived from multiple sources, and
grain interlocking is just one of them. I think recent research has shown that
grain interlocking does not play a large role in concrete strength. It's
unclear to me if your post is talking about grain interlocking or
cement/aggregate bonding. I'm not up to speed on research in this area, but I
do not believe that you can have a rounded sand that is so smooth that bonding
doesn't occur and the idea that the concrete "turns to dust" under any serious
load is something that I personally have never heard of.

In fact, the more angular the aggregate is the less workable the concrete
becomes. There is a sweet spot of angularity that is desired. I believe the
main advantage to increased angularity is in durability (which is due to
interlocking, I think, as well as increased void ratio leading to better air
entrainment).

Also - the size of the grains is more important than angularity, so I also
disagree with the statement that sand "as fine as possible" can be useful for
construction work in the context of concrete. While tautologically true
because anything too fine (passing #200) would be classified as a silt instead
of a sand, the way that it's written is deceptive.

~~~
lightedman
"Also - the size of the grains is more important than angularity, so I also
disagree with the statement that sand "as fine as possible" can be useful for
construction work in the context of concrete."

Disagree all you want but that doesn't change the fact I've done building
construction, including laying foundation, and finer sand is far superior to
coarser sand. In fact, coarser sand is rather horrible for construction.

[https://www.youtube.com/watch?v=l6bTSJVLCVI](https://www.youtube.com/watch?v=l6bTSJVLCVI)

~~~
abduhl
I still don't understand what exactly you're talking about. Are you talking
about sand used for concrete or sand in general (e.g. - for subgrade soils).

Sand used in concrete needs to meet a gradation requirement. The gradation
requirement uses all sizes of sand as aggregate.

And if we are comparing credentials (which I assume is what your building
construction story and youtube link is for?), then I've done nothing but put
holes in the ground and fill them up with concrete for almost a decade. Here's
what I was doing in 2014:
[https://www.youtube.com/watch?v=E4Ixw69woSA](https://www.youtube.com/watch?v=E4Ixw69woSA)

~~~
lightedman
I did the construction globally, from USA to UK to Saudi Arabia.

I'm talking about both sand in construction and in general (like for
glassblowing, etc.) Portland cement uses the finest sands possible for holding
concrete aggregate, which you only really tend to find in desert areas (if
you're lucky enough to find a spot that hasn't been above water for more than
a million years, that's one reason construction-grade stuff is so hard to
find.)

Now days, I do very similar to your link, except it's through mountains, and
terminates inside the mountain. Minerals extraction is fun!

------
dirtyid
This is a topic with very scant literature. I'm curious if there's an account
of global sand reserves. Unlike oil/shale, other mineral resources, it seems
like available construction sand is basically all discovered by virtue of
being on the surface. I'm wondering if there are predictions for peak sand,
what current sand reserves translates to in total tons of future concrete
production etc. Otherwise it seems like the kind of resource that need to
managed properly, seeing how land reclamation projects will be increasingly
necessary with raising water levels. Engineered timber can replace some
building needs, but I can't think of an alternative to concrete for other
critical infrastructure like roads.

~~~
owyn
I'd be really interested to know the economics here too. Forestry is something
that can be done for a profit, but what if it takes 1000 years to make sand?

~~~
abduhl
It doesn’t take 1000 years to make sand. You take a rock and crush it. You’ve
got sand.

It just happens to be easier and cheaper to dredge where there aren’t any
environmental laws.

------
rapnie
For an overview on the issues of sand extraction the documentary "Sand Wars"
(2013) is interesting to watch.

[https://en.wikipedia.org/wiki/Sand_Wars](https://en.wikipedia.org/wiki/Sand_Wars)

------
jelliclesfarm
The sand mafia is real. It’s happening in India too.

Sand isn’t ‘renewable’ ..loss of river sand is just going to make things
worse.

I don’t want to sound like a curmudgeon..but human extinction is imminent is
we don’t protect our ecosphere and biosphere..this is assuming climate change
can’t be stopped and so let’s not take that into account..lets assume that it
won’t happen.

As a super apex predator, we need the underlying structure of our ecology and
environment and all the habitats below us in the food chain..most importantly
insects and frogs and birds...for us to survive here on this only planet we
know.

The solution is just a severely whittled population with measures that will
get us to a desired 2-3 billion in 150-200 years.

We have to maintain genetic diversity and dna code hygiene..it’s not genocide
or eugenics if we don’t target a particular people or group for erasure. It’s
for ALL of us.

This can be achieved by incentivizing those who subscribe to a non
transferable quota of 1/2 surviving progeny. And preservation of their genetic
material. Quality over quantity. The crush of human population will be our
undoing.

~~~
Aperocky
That’s fearmongering. Not even WWII managed to kill even 10% of the human
alive then. Climate change could have caused half of humans to die which would
be exceedingly extreme in our civilization but I don’t buy extinction
argument.

For other species, population goes down by half is just another day. It
wouldn’t even be classified as vulnerable if it were just going down by half.
A large proportion of us will suffer or die, but that is not extinction,
there’s no need to over dramatize things when the fact is serious enough.

------
avgeek23
A good insight on how daming and sand dredging is destroying the Mekong is in
the latest Grand Tour episode. The extent of the damage that humans have
caused to other humans surviving on the river is unfathomable.

------
ninguem2
I read somewhere recently that the melting of ice in Greenland is exposing
vast quantities of sand. I am not sure if this will make a difference as
transporting the sand would then be a problem.

------
lazylizard
If its too expensive to dredge. Then someone will produce concrete that
doesn't use alluvial sand. They're just pricing it right.

~~~
Synaesthesia
But by the time it becomes too expensive to dredge we may have majorly fucked
up some ecosystems. The loss in depth of the Mekong means seawater comes in
and destroys plants, and sand is also part of the natural ecosystem as
described in the article.

~~~
zo1
>"But by the time it becomes too expensive to dredge we may have majorly
fucked up some ecosystems."

I know it may be unpleasant to hear this... But some of us don't actually
care. Seriously, somewhere we got "stuck" into thinking that we should (or
can) perfectly preserve ecosystems whilst simultaneously advancing our
civilization into amazing new levels.

However, if you look at it objectively we've already demolished and
transformed huge swathes of the planet anyways without blinking; but now
selectively decide to "preserve" some other things. Just look at all the land
our cities take up, the roads that cut our landscape, the beaches that are
peppered with housing, the rivers we've diverted, the dams we've constructed,
the changes we've caused in the evolution of plants and animals, etc. Maybe
even imagine how (perhaps horrible) our planet looks at night from outer space
due to the lights we've erected all over it instead of letting it be naturally
dark as it's been for eons.

------
hackerbabz
I live in a Mekong country and I’m starting to wonder if I’ll need to flee
just to find water.

~~~
istorical
May want to emmigrate before mass climate refugee outflows become a real
planetary scale disaster in case countries start to restrict immigration.

~~~
anonperson8
Now is the time to plan for 2040 and beyond. I’m in a “developed” country and
were looking at options regarding acquiring multiple inherited citizenships to
maximise our options for this unknown future.

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vectorEQ
is it some specific type of sand or whaT? i mean... china has loads of desert,
it's a big issue there :D don't they just take their own sand?? is there some
special type of sand required for good cement which is rare or something?

~~~
0ldblu3
The article states that the sand in a desert is to "smooth" to properly bind
in concrete. So yes, the demand is for sand with characteristics that work in
concrete. The article also states that Cambodia has banned exporting sand and
also that Singapore recorded record exports from Cambodia. I suspect that
large scale corruption is in play.

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JackPoach
Sand never struck me as rare or valuable. This is unfortunate.

