The Necessity for a New Global Water
Model
Som Karamchetty
Problem:
There is a severe
shortage of water in most countries. This shortage is in terms of clean and
potable water for drinking and cooking. The shortage extends to other sectors
like farming, industries, and a number of other uses.
Key Points:
All materials on
earth only get recycled and undergo transformation. Except for sunshine,
nothing comes from outside. Thermal radiation to outer space dissipates some of
the energy. All the water we get on the earth is already here. No water leaves
the planet nor enters it. Hence, it is unlikely that the earth would get any
supply of fresh water from outer space. Furthermore, there is an enormous
quantity of water in the oceans on the earth although it is salty and not
directly usable. Although we complain about water shortage, the real problem is
not getting enough water where and when we want it.
The earth will
continue to receive energy from the sun so long as the sun exists and the earth
rotates around the sun with no permanent obstruction in between. Consequently, technologies
to reform and recycle water using solar energy should be the best option we
have on earth to get plenty of water where we need and when we need it.
Solar evaporation
of seawater is almost continual but it is of finite capacity. It may be
possible to increase it to some extent. If we succeed in increasing the
seawater evaporation and make sure that it falls on the land and not back into
the oceans, we will get more fresh water on the land.
The next step is to
keep the fresh water from running fast to the oceans. We should work on water
infrastructure with good storage. In certain locations, land based fresh water
evaporates due to the incidence of sunshine.
The Water Cycle:
The earth is lucky
to have an enormous storage of water in the oceans. Electromagnetic energy from
the sun (solar radiation) reaches the earth continuously. Owing to the
incidence of thermal energy in the form of solar radiation, water in the oceans
(as well as elsewhere) evaporates, moves up to higher altitudes and clouds are
formed. Different parts of the earth react differently to the solar radiation
in terms of absorption, radiation and retransmission. On the areas of earth
where there is no or a little water, under the effect of solar radiation, the
surface of the earth and the air gets warmer. The warmer air moves up. The net
result is that the air is heated differentially at various locations. Together
with other causes (earth’s rotation, gravity, and so on), there will be
pressure differences and air movements in the earth’s atmosphere. The net
result is that the water vapor laden air over the oceans moves up into higher
altitudes and moves from one location to another. As the earth moves on its own
axis, only parts of it are receiving solar radiation in different proportions
and also for some periods of the day and other parts are exposed to cold deep
space. Thus, any portion of the earth is going through periods of heating (due
to exposure to the sun) and cooling (due to exposure to the cold deep space) in
a day. Since the earth’s rotation is at an inclination, there are seasonal
variations in the winds.
The water vapor in
the air moves upwards and forms clouds, which move with the wind from high
pressure regions to low pressure regions. With low temperatures at higher
altitudes, the water vapor in the clouds condenses into water. At even higher
altitudes, the water vapor in the clouds leads to the formation of snow. As
water and snow are heavier than the surrounding air at the higher altitudes,
they come down to earth as rain or snow fall. Some water returns to the oceans
in the form of rain and snow fall and is of no immediate benefit to us. That
water which comes down to the landed areas is of use to us in various ways.
However, in some cases, upon reaching the mountains, the water flows downhill
and along the rivers so fast that it reaches the ocean depriving us of any benefit.
There is an
important water cycle that benefits us. Solar radiation evaporates sea water
and fresh water becomes clouds and moves up high into the sky. The clouds move
and rain forms thus causing rains and snowfall. Some of the rain and snowfall
occurs over the sea and becomes salt water again. Thus, only that water which
rains or snows on land becomes available to humans for use.
Ideal
Situation:
What do we wish? We
want the fresh water that comes down in the form of rain and snow in a certain
fashion.
·
We
want as much water as we like to use to come down to us on the land and not
directly back to the oceans.
·
We
want the water to come to us where we want and when we want it to suit our use
patterns, such as in farming.
·
We
want to store water so that fresh water is prevented from running back to the
oceans.
·
We
want to lessen the evaporation of freshwater, which is on the land, while we
want unusable water on the land to evaporate.
Research
Thrusts:
In order to fulfill
our wishes (as noted above), we may have to do some research in science and engineering
of the water movement in the atmosphere. Such research should have the
following thrusts.
·
How
to increase (essentially control the rate of water evaporation and
precipitation) in the daily and diurnal cycles?
·
How
to minimize the water returning as rain or snow to the oceans?
·
How
to minimize water returning to the oceans as river flow (floods)?
·
How
to get as much water as we need on the landed areas?
·
How
to get controlled quantities of water when we need it?
Modeling:
The first task is
to develop a model that analyzes the water flow in the atmosphere. This is
perhaps possible by modifying the current atmospheric sciences (weather)
models. These are currently used to forecast the weather patterns at various
scales and time horizons.
The next task is to
construct models that incorporate various large scale changes in the earth’s
ecosystems and find their effects on weather. In such virtual scenarios, the
following questions can be posed.
·
If
large swaths of desert land are filled with (sea water filled) lakes and/or
reforested, what would be the changes in weather pattern?
·
If
large parts of the oceans in selected regions are covered (water is not allowed
to evaporate under solar radiation), what changes in weather would be caused?
·
Once
cause and effect relationship is established in virtual models, questions can
be posed in terms of what should be done to get a certain set of effects?
·
With
such models, it could be possible to augment (increase or decrease or change
the timing or rate) the amount of rain or snowfall in certain areas of the
earth.
·
In
the end, such models might help us to harvest that water which now goes back to
the oceans.
·
Of
course, when such models are developed, the question if any of these mechanisms
can be under sensible human control should also be addressed and answered.
Recommendations:
Develop a model
that analyzes the mechanisms that cause the above described flows.
As we pass more of
our jobs to intelligent machines, we should undertake such advanced modeling to
address such harder mega problems. Of course, Artificial Intelligence might
also come in to help us in this effort.
Useful References
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