Potable Water, the kind that you drink and cook with is going to be fought over in the near future. Some of the reason is due to Climate Change, the changes in weather patterns has lead to long term drought in areas that had had sufficient water. Some of the reason is that humans seem to care little how much they pollute the world around them. Even in the middle of the Pacific Ocean, you find garbage that was "disposed of" by humans. Ocean shores are heavily polluted - often disgustingly so. I found myself staring at a human turd while swimming near Victoria.
Some Nations are already dependent on desalination plants to provide the water necessary for their population to survive. The desalination plants in Israel, Saudi Arabia and Singapore use combined evaporation and reverse osmosis technology. This is because their intake water is so heavily polluted that that flash boiling the water does not eliminate the pollution, the re-condensed water must be further processed through reverse osmosis to make it safe for human consumption.
What people don't realize is that wells to access ground water are not the answer in most of the world. There is an article on CBC that talks about how renewable ground water actually is. Only 6% of ground water over 50 years is renewed. That's why Israel and Saudi Arabia must rely on desalination plants for their water. http://www.cbc.ca/news/technology/groundwater-study-1.3318137
Both Israel and Saudi Arabia are supplying 50% or more of their needed water through desalination.
Some Nations are already dependent on desalination plants to provide the water necessary for their population to survive. The desalination plants in Israel, Saudi Arabia and Singapore use combined evaporation and reverse osmosis technology. This is because their intake water is so heavily polluted that that flash boiling the water does not eliminate the pollution, the re-condensed water must be further processed through reverse osmosis to make it safe for human consumption.
What people don't realize is that wells to access ground water are not the answer in most of the world. There is an article on CBC that talks about how renewable ground water actually is. Only 6% of ground water over 50 years is renewed. That's why Israel and Saudi Arabia must rely on desalination plants for their water. http://www.cbc.ca/news/technology/groundwater-study-1.3318137
https://en.wikipedia.org/wiki/Desalination... The water that supplies aquifers and wells that billions of people rely on around the world is mostly a non-renewable resource that could run out, a new Canadian-led study has found.
While many people may think groundwater is replenished by rain and melting snow the way lakes and rivers are, underground water is actually renewed much more slowly.
In fact, just six per cent of the groundwater around the world is replenished within a "human lifetime" of 50 years, reports University of Victoria hydrogeologist Tom Gleeson and his collaborators in a new study published in the journal Nature Geoscience today.
That water tends to be mainly found within a few hundred metres of the surface, where it is most vulnerable to being contaminated by pollution or depleted by higher temperatures and reduced rainfall as a result of climate change, the researchers found. ...
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Scientists had previously made a rough estimate of the amount of groundwater in the world, but no one knew how much is renewable and how quickly it's replenished.
Gleeson and his colleagues came up with a way to figure out what groundwater was less than 50 years old. In the 1960s, during the Cold War, a number of countries were doing above-ground nuclear testing. This introduced a radioactive form of hydrogen, called tritium, into the world's water supply.
The researchers figured that groundwater with high levels of tritium was renewed since the 1960s. Groundwater with negligible levels was older.
By looking at 3,500 measurements of tritium in groundwater from 55 countries and using computer models to trace the flow of groundwater around the world, they were able to estimate how much groundwater was young and renewable and how much was older. ...
... Gleeson said in places like California and the U.S. Midwest, people are already using "non-renewable" water that is thousands of years old and in places such as Egypt, they're tapping into water that may have last been renewed a million years ago. Such old water isn't just non-renewable — it tends to be saltier and more contaminated than younger groundwater.
In addition, overusing groundwater, either old or young, can lower subsurface water levels and dry up streams, which could have a huge effect on ecosystems on the surface, Gleeson added.
He hopes the study will help remind and motivate people to manage their groundwater resources better. "And realize that it's finite and a limited resource that we need to respect and manage properly."
Both Israel and Saudi Arabia are supplying 50% or more of their needed water through desalination.
