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As a general rule, the most successful man in life is the man who has the best
information
For most of human history we’ve been consuming resources at a rate lower
than what the planet was able to regenerate.
Unfortunately we
have crossed a critical threshold. The demand we are now placing on
our planets resources appears to have begun to outpace the rate at which nature can replenish them.
The gap between human demand and supply is known as ecological
overshoot. To better understand the concept think of
your bank account – in it you have $5000.00 paying monthly interest. Month after month
you take the interest plus $100. That $100 is
your financial, or for our purposes, your ecological overshoot and its withdrawal is obviously unsustainable.
“One lesson from the five great global
extinctions is that species and ecosystems come and
go, but the evolutionary process
continues. In short, life forms have a future on Earth, but humankind’s
future depends on its stewardship of ecosystems that favor Homo sapiens.”
John Cairns, Jr., Future of Life on Earth
Water
Freshwater aquifers
are one of the most important natural
resources in the world today,
but in recent decades the
rate at which we’re pumping them dry has more than doubled. The amount of water pumped has gone from 126 to 283
cubic kilometers per year - if water was pumped as rapidly from the Great Lakes they would be
dry in roughly 80 years.
These fast
shrinking underground reservoirs
are essential to life on this planet.
They sustain streams, wetlands, and ecosystems and they resist land subsidence and salt
water intrusion into our fresh water supplies.
Many people think of aquifers as
underground lakes but that’s
not the case - the water is held
between rock particles.
Water infiltrates into
the soil through pores
and cracks until it reaches what is called the zone of
saturation - all of the spaces between
the rocks are filled with
water, not air. This zone of saturation occurs because water infiltrating the soil reaches an impermeable layer of rocks it can’t soak through.
Water held in aquifers is known as groundwater.
The water table is located
at the top of the zone of saturation.
Almost all of the planet’s liquid fresh water is stored in aquifers. Some of the largest cities in the developing world
- Jakarta, Dhaka, Lima, and Mexico City - depend on
aquifers for almost all their water.
Most rural areas
pump groundwater from wells drilled
into an aquifer.
There are two types of aquifers: replenishable (a permeable layer of rock above
the water table and an impermeable one beneath it) and non-replenishable (also known as fossil aquifers, no recharge) aquifers.
Most of the aquifers in India
and the shallow aquifer under the North China Plain are
replenishable. When these are depleted, the maximum
rate of pumping is automatically reduced to the
rate of recharge or refill.
For fossil aquifers - such as the vast U.S. Ogallala aquifer, the deep aquifer under the North China Plain, or
the Saudi aquifer - depletion brings pumping to an end.
Groundwater represents
about 30 percent of the available fresh water on the planet -
surface water accounts for less
than one percent. The rest
is locked up in glaciers
or the polar ice caps.
The highest rates of groundwater depletion are in some of the world's major agricultural centers:
- Northwest India
- Northeastern China
- Northeast Pakistan
- California's central valley
- Midwestern United States
China’s wheat
crop is mostly grown in the semi-arid northern part of the
country and is particularly
vulnerable to water shortages.
A World Bank study indicates
that China is over pumping three river basins in
the north, the Hai, the Yellow
and the Huai.
Irrigated land accounts
for four-fifths of the grain harvest
in China.
In India the water situation is even more serious - the 21 million wells drilled are lowering water
tables in most of the country - in North Gujarat, the water table is
falling by 6 meters per year. In the state of Tamil Nadu
falling water tables have dried
up 95 percent of the wells owned
by small farmers.
Irrigated land accounts
close to three-fifths of the grain harvest in India.
Indian water well drillers are now using modified
oil drilling technology and going as deep as 1,000 meters.
In North America the major concern is over water levels in the Ogallala aquifer under the U.S. Great
Plains - the world's bread
basket. The Ogallala is
the world's largest known aquifer having an approximate area of
450,600 square kilometers and stretches
from southern South
Dakota through parts of Nebraska, Wyoming,
Colorado, Kansas, Oklahoma, New Mexico, and northern
Texas.
The Ogallala Aquifer was formed roughly
10 million years ago when water flowed onto the
plains from retreating
glaciers and streams of the Rocky Mountains. The Ogallala is no longer being
recharged by the Rockies
and precipitation in the region
is only 30-60 cm per year.
In three leading grain producing states
- Texas, Oklahoma, and Kansas - the underground water table has dropped by more than 30 meters.
In the Pakistani part of the fertile Punjab
plain, the drop in water tables appears to be similar to that in India.
Iran is over pumping its aquifers by an average of 5 billion tons of water per year.
Saudi Arabia,
relying heavily on subsidies, developed an
extensive irrigated agriculture based
on its deep fossil aquifer - and they sucked it
dry. Some Saudi farmers are now pumping water from wells that are 4,000 feet deep.
In Yemen the water table under most of the country is falling by roughly 2 meters a
year. In western Yemen’s
Sana’a Basin, the estimated
annual water extraction of 224 million tons exceeds the annual recharge of
42 million tons, this drops the water table 6 meters per year.
In Mexico the demand for water is outstripping supply. In the
agricultural state of Guanajuato the water table is
falling by 2 meters or
more a year.
When groundwater
is depleted the effects (besides lessening of supply or no more
water) can be drastic. Land subsidence happens
when porous formations that once held water collapse resulting in the surface layer settling.
Water won’t compress,
but when the water is sucked out of an aquifer air fills the void between the rocks where the
water use to be. Air compresses and the ground sinks or compacts - the aquifer will never hold the same amount of water again.
One study shows that from 1986 to 1992 some parts of
the Mexico City Aquifer’s water levels dropped 6 to 10 meters. Areas of Mexico City, as a consequence,
have fallen as much as
8.5 meters. The subsidence (ground
compaction) is also damaging the sewer system, potentially leading to untreated sewage mixing with fresh
water in the aquifer.
In March of
2009, Enoch City in Iron County,
Cedar Valley Utah, contacted
the Utah Geological Survey (UGS) about what they believed
to be a fault running through one of their new
subdivisions. It was determined
by the UGS that it was a fissure caused by the groundwater level dropping as much as 114 feet since 1939 due to pumping more groundwater than is recharged
(refilled).
Another effect
of over pumping is saltwater intrusion. If too much groundwater is pumped out from coastal aquifers saltwater may flow into them causing contamination of
the aquifer. Many coastal aquifers - the Biscayne Aquifer near Miami and the New Jersey Coastal
Plain aquifer for example
- have problems with saltwater intrusion.
Conclusion
Streams, rivers and
lakes are almost always closely connected with an aquifer. The depletion of aquifers doesn’t allow these surface waters to be recharged - lowering water levels in aquifers is being
reflected in reduced amounts of water flowing at the surface. This is
happening along the Atlantic Coastal
Plain, groundwater depletion
is also responsible for the Yellow
River in China not reaching the ocean
for months at a time, the
failure of the Colorado River in the U.S. and the
Indus River in Pakistan failing to reach the ocean every day.
"If you let
the population grow by extending
the irrigated areas using
groundwater that is not being recharged, then you will run
into a wall
at a certain point in time, and you
will have hunger and
social unrest to go with it. That is something
that you can see coming
for miles." Marc Bierkens of
Utrecht University in Utrecht, the Netherlands
Water is a commodity whose scarcity will have a profound effect on the world within the next decade - the danger to us from the worsening ecological overshoot concerning the world’s fresh water supply makes the reevaluation of our values mandatory. We will have to drastically change the way in which we view
our freshwater as a resource.
“Current estimates indicate that we will not have enough water to feed ourselves in 25 years time.” International Water
Management Institute (IWMI) Director General Colin
Chartres
The central
issue for us over the next few decades
is not climate change or
the global financial crisis
- it is whether humanity can achieve and sustain the enormous harvest we need
from this planet to feed ourselves.
Is this soon to be front and center issue - our
fresh water resources -
on your radar screen?
If not maybe it should
be.
Richard Mills
Aheadoftheherd.com
If you're
interested in learning more about the junior resource market please come and visit
Richard at www.aheadoftheherd.com. Membership is free, no credit card or personal
information is asked for.
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