In Sahara there is these huge "pools", higher ground surrounded
lower areas which are these huge "pools" on desert, that some has
even big areas under sea-level in bottom of these "pools". These
pools mostly are located very near coast-line, and with pumps and
pipes of few hundred kilometers these "pools" could be filled with
sea-water, until vaporizing (increasing while wideness of "pools"
would expand) would match water flowing in, when surface of "pools"
would stop rising and around them would be coming huge oasiss (as
sand filters salt from sea-water, when few meters from coast of
these "pools" would be easy to get fresh water with dwells and
pumps), and these oasiss could reach kilometers inland as water
travels far away in sand. For agricultural activities and
inhabitation there would be huge areas to be used, these "pools"
would be biggest lakes in the world.
But real meaning of these pools would be elsewhere, because
vaporizing from those would be huge in worlds warmest areas with
most heat radiation from sun (without clouds). Water-steam would
for clouds filled with water, that would be going with major winds
to south and east (for example as turned by coriolis-force) into
mountains middle of Sahara and mountains west in Arabian peninsula,
forming rains at least finally there. It would form rivers and
lakes into area, from which there is obvious signs around mountains
in middle of Sahara from past times (from last ice age, when Sahara
was inhabited by black Africans).
Reason why these "pools" would change situation so radically is
that air-masses rise to upper layers of atmosphere from equator,
until arriving to north and coming down at 30´-line east-west (at
coast of Libya/Egypt), and go from there as winds we notice to
south and north, leaving winds going south without moisture from
Mediterranean Sea, as winds going to north (Europe) will have all
of it. So only way to get moisture to Sahara is to move
water-masses from Mediterranean Sea to these "pools" under this
30´-line to vaporize (Mediterranean Sea will have water more
through Gibraltar straits from Atlantic).
Only bad side this could have would be destruction of unhabited
waste-land desert, when besides worthless deserts there would be
lots of land suitable for agricultural and living use, providing
living for millions of unemployment workers and people without land
(believe me, deserts will be green as long as they get enough
water, seeds for plants have come there by wind, in nature-document
water was poured in top of dune and green plant rose from it, dying
without water until it got more water and got back to life). Here
would be huge opportunities for profits, buy worthless desert and
change it for agricultural use, even possibly oil could be trilled
from bottom of these pools and transported to coast by ships
(cheaper than by trucks) or by underwater-pipes (no danger of
sabotage). Also water pumping from under Libyan desert would get
more fresh water below desert sand from these pools. These ideas
can be expanded by even redirecting rivers just before it will end
into oceans, so that fresh water of it will not be wasted but
used to water deserts.
