India is running out of water, fast

[Yo_Mama_Been_Loggin]

At least 21 cities in India, including capital New Delhi, Bengaluru, Chennai and Hyderabad, will run out of groundwater by 2020, affecting around 100 million people.

India's news network NDTV said 40 percent of India's population will have no access to drinking water by 2030, according to a report by the National Institution for Transforming India (NITI Aayog) - the country's principal planning organisation.

One of the worrying predictions of climate change has been a weakening monsoon season in South Asia. For the last five years, rainfall in the region has been below average, with 2015 being the worst at 86 percent.

This year's late monsoon progress is worrying, with a prolonged heatwave aggravating the situation. From Andhra Pradesh to Bihar, the late onset of monsoon cloud and rain has allowed daily temperatures to remain higher than normal.

The city of Chennai in Tamil Nadu state is now virtually out of water, while it has been hitting temperatures over 41C for nine of the last 10 days; on June 10, it was 43C. The average for June in the city is 37C and the record 43.3C.

Millions of people have been forced to rely on water from tank trucks in the southern Tamil Nadu, which had a 62 percent shortfall in monsoon rains last year.

-more-

https://www.aljazeera.com/news/2019/06/india-running-water-fast-190620085139572.html

[marylandblue]

2. It's expensive because fundamental physics makes it energy intensive,

like pushing a rock up a hill. I read decades ago that we would have water wars by 2015. The prediction seems like it was just a bit too early.

[hunter]

5. Modern desalinization plants require about 3 kWh to desalinate a cubic meter of water.

That's roughly equivalent to pumping it up a 1000 meter hill.

A meter is 3.28 feet

A cubic meter of water is about 264 gallons.

Imagine carrying a five-gallon bottle full of water up a 3000 foot mountain, fifty times.

The theoretical maximum desalinization efficiency is a little over 1 kWh per cubic meter.

(Anyone is free to scold me for my math, it was back of the envelope stuff... I hope I didn't misplace any decimal points.)

If we burn fossil fuels to desalinate water then we are contributing to global warming, which may have been what caused the water shortage in the first place.

[progree]

8. How will you collect the water that evaporates? How much cost and material (which takes

energy to mine, build, and construct) for how many gallons per hour? How to get the water to condense to speed all this up? (without spending a ton of energy on cooling the condensation surfaces).

Edited to add - I see Wikipedia lists several methods of desalination, the first being solar desalination which sounds closest to evaporating and collecting evaporated water. Unfortunately that footnote [8] leads to an abstract (only) that says nothing about this.
https://en.wikipedia.org/wiki/Desalination

[progree]

13. "I don't know. I'm not a scientist. But in two minutes I already came up w an alternative to the

old"

You are not the first one to think of this, as the desalination links that I and Hunter provided show. The idea popped up in my head too, long before seeing any of your posts. But there is a big big difference between having an idea, and actually getting it to work on the scale needed and at a cost and energy usage that is less than the existing alternatives.

How many tons of plastic would you need to produce a gallon of water a minute?

Try it at home -- put some water in a bowl. Put the bowl on some tray, and make some kind of plastic "dome" or covering to cover it all. (Or just put a larger bowl over it). Then tell me how much evaporated water you collect. Basically all you are going to end up with is a dome full of saturated air. Any method to condense and collect that water beyond a trivial amount is going to take energy.

"Unless there's a profit marign"

Believe me, if you or someone can make this work at less cost and energy usage than existing methods (takes a lot of petroleum and energy to make that enormous plastic cover and maintain the very massive thing), there will be plenty of profit.

And keep it from being blown away into the ocean (which has plenty enough plastic already in it).

I'm not a scientist (despite having a master of science degree), but rather an engineer.

[progree]

22. Thanks. Have a great weekend yourself

[hunter]

9. It's all energy, solar and geothermal heat included. The universe doesn't care.

Desalinization requires energy.

Solar thermal desalinization has been problematic.

In any case, it requires large areas of land.

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

I'd post scholarly articles, but wikipedia is fairly good.

Photovoltaic powered reverse osmosis systems might work just as well.

I've seen a few grandiose Buckminster Fuller-esque schemes involving huge areas enclosed in glass that essentially mimic natural hydrologic cycles within, sometimes including mile high geodesic chimneys in which fresh water condenses as warm moist air rises.

There are also schemes to catch water from air.

But the rules of thermodynamic are inviolable.

[hunter]

14. Our E&E Group dissident NNadir has imagined a few nuclear powered supercritical seawater schemes.

Nuclear power may be a sophisticated way to desalinate seawater, as well as extracting many useful elements and chemicals.

Supercritical seawater, as it exists about three kilometers and more below the ocean floors, plays the larger part in the overall chemistry of earth's oceans.

The idea that ocean chemistry was determined by water flowing off the land and sedimentary processes was naive.

But rising carbon dioxide in the atmosphere and oceans is clearly our fault. The earth doesn't care, it has seen worse, sometimes much worse, but we humans should care if we wish many of our nations to remain hospitable for our kind.

[Finishline42]

15. I would think another issue for desalination

would be the salt deposits on everything used in the process - another energy eater.

[hunter]

16. Earth's ocean water is nasty stuff.

It will eventually ruin most things humans build.

There are a few science fiction stories where space aliens simply can't imagine intelligent life could exist on a warm oxygen rich saltwater ocean planet.

[Bradshaw3]

4. India isn't alone

The water source of 800 million people is disappearing at an alarming rate.

From CNN:
"Climate change is eating away Himalayan glaciers at a dramatic rate, a new study has revealed.

Spanning 2,000 kilometers and harboring some 600 billion tons of ice, Himalayan glaciers supply around 800 million people with water for irrigation, hydropower and drinking.
But they have been losing almost half a meter of ice each year since the start of this century -- double the amount of melting that occurred between 1975 and 2000 -- according to the Columbia University researchers behind the study.
Recently, the glaciers have lost around 8 billion tons of water a year -- the equivalent of 3.2 million Olympic-size swimming pools, say the researchers. And that could potentially threaten water supplies for hundreds of millions of people across parts of Asia."

https://www.cnn.com/2019/06/19/world/himalayan-glaciers-melting-climate-change-scn-intl/index.html

[pscot]

7. The Indus, the Ganges, the Mekong

the Yangtze and the Yellow rivers all spring from the Tibetan plateau.

[hunter]

11. Well that sucks.

The people of our time will be loathed for our fossil fuel burning ways by all surviving humans.

[pscot]

18. Found the optimist

[hunter]

19. There will be surviving humans.

But they won't respect us.

[pscot]

20. By the 3rd generation they'll remember us

as the stuff of legends.

[hunter]

21. Dead Titans, the second generation of divine beings, succeeding the primordial deities

[kat3rinamarquez]

23. I agree.

Human extinction is slowly becoming more realizable.