A fourth method (after reverse osmosis and oil or solar
powered distillation) for desalination in Saudi Arabia and
other countries with distant deserts and water shortage (like
Israel, Lybia and Navada)
Dig a giant subterranian seawater lake in the middle of the
desert, (actually hundreds
of tunnels) lower than sea level.
Above it, on the surface create a brine lake, used for making
salt. (In Israel this could be accomlished by digging giant
seawater storage tanks under the now dry areas of the dead
The seawater is then pumped at the biginning from the sea
but then continues to flow gravity.
For desalination the seawater is pumped up and sprayed onto
chambers where it is constantly being evaporated and
condensed back with less and less salt. The fresh water is
gathered and sent nearby to create a natural-like vegetative
green environment in the uninhabited formerly harsh areas.
The brine is gathered on the surface and either evaporated
for salt or used as a salt lake for for tourism.