OT: Environmental note, water is drying up

[Guest guest]

Came across this, makes you wonder...

 

HYPERLINK

" http://www.earth-policy.org/Books/Seg/PB2ch03_ss2.htm " http://www.earth-poli

cy.org/Books/Seg/PB2ch03_ss2.htm

 

Dave

 

" Don't be afraid to try new things. After all, the Ark was built by

amateurs, and the Titanic was built by professionals "

-Unknown

 

 

 

WATER TABLES FALLING AND RIVERS RUNNING DRY

 

 

 

Lester R. Brown

 

As the world’s demand for water has tripled over the last half-century and

as the demand for hydroelectric power has grown even faster, dams and

diversions of river water have drained many rivers dry. As water tables

fall, the springs that feed rivers go dry, reducing river flows.

 

Scores of countries are overpumping aquifers as they struggle to satisfy

their growing water needs, including each of the big three grain

producers—China, India, and the United States. More than half the world’s

people live in countries where water tables are falling.

 

There are two types of aquifers: replenishable and nonreplenishable (or

fossil) 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.

 

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. Farmers who lose their irrigation water have the option

of returning to lower-yield dryland farming if rainfall permits. In more

arid regions, however, such as in the southwestern United States or the

Middle East, the loss of irrigation water means the end of agriculture.

 

The U.S. embassy in Beijing reports that Chinese wheat farmers in some areas

are now pumping from a depth of 300 meters, or nearly 1,000 feet. Pumping

water from this far down raises pumping costs so high that farmers are often

forced to abandon irrigation and return to less productive dryland farming.

A World Bank study indicates that China is overpumping three river basins in

the north—the Hai, which flows through Beijing and Tianjin; the Yellow; and

the Huai, the next river south of the Yellow. Since it takes 1,000 tons of

water to produce one ton of grain, the shortfall in the Hai basin of nearly

40 billion tons of water per year (1 ton equals 1 cubic meter) means that

when the aquifer is depleted, the grain harvest will drop by 40 million

tons—enough to feed 120 million Chinese.

 

In India, water shortages are particularly serious simply because the margin

between actual food consumption and survival is so precarious. In a survey

of India’s water situation, Fred Pearce reported in New Scientist that 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 (20 feet) per year.

In Tamil Nadu, a state with more than 62 million people in southern India,

wells are going dry almost everywhere and falling water tables have dried up

95 percent of the wells owned by small farmers, reducing the irrigated area

in the state by half over the last decade.

 

As water tables fall, well drillers are using modified oil-drilling

technology to reach water, going as deep as 1,000 meters in some locations.

In communities where underground water sources have dried up entirely, all

agriculture is rain-fed and drinking water is trucked in. Tushaar Shah, who

heads the International Water Management Institute’s groundwater station in

Gujarat, says of India’s water situation, “When the balloon bursts, untold

anarchy will be the lot of rural India.”

 

In the United States, the U.S. Department of Agriculture reports that in

parts of Texas, Oklahoma, and Kansas—three leading grain-producing

states—the underground water table has dropped by more than 30 meters (100

feet). As a result, wells have gone dry on thousands of farms in the

southern Great Plains. Although this mining of underground water is taking a

toll on U.S. grain production, irrigated land accounts for only one fifth of

the U.S. grain harvest, compared with close to three fifths of the harvest

in India and four fifths in China.

 

Pakistan, a country with 158 million people that is growing by 3 million per

year, is also mining its underground water. In the Pakistani part of the

fertile Punjab plain, the drop in water tables appears to be similar to that

in India. Observation wells near the twin cities of Islamabad and Rawalpindi

show a fall in the water table between 1982 and 2000 that ranges from 1 to

nearly 2 meters a year.

 

In the province of Baluchistan, water tables around the capital, Quetta, are

falling by 3.5 meters per year. Richard Garstang, a water expert with the

World Wildlife Fund and a participant in a study of Pakistan’s water

situation, said in 2001 that “within 15 years Quetta will run out of water

if the current consumption rate continues.”

 

Iran, a country of 70 million people, is overpumping its aquifers by an

average of 5 billion tons of water per year, the water equivalent of one

third of its annual grain harvest. Under the small but agriculturally rich

Chenaran Plain in northeastern Iran, the water table was falling by 2.8

meters a year in the late 1990s. New wells being drilled both for irrigation

and to supply the nearby city of Mashad are responsible. Villages in eastern

Iran are being abandoned as wells go dry, generating a flow of “water

refugees.”

 

Saudi Arabia, a country of 25 million people, is as water-poor as it is

oil-rich. Relying heavily on subsidies, it developed an extensive irrigated

agriculture based largely on its deep fossil aquifer. After several years of

using oil money to support wheat prices at five times the world market

level, the government was forced to face fiscal reality and cut the

subsidies. Its wheat harvest dropped from a high of 4 million tons in 1992

to some 2 million tons in 2005. Some Saudi farmers are now pumping water

from wells that are 1,200 meters deep (nearly four fifths of a mile).

 

In neighboring Yemen, a nation of 21 million, the water table under most of

the country is falling by roughly 2 meters a year as water use outstrips the

sustainable yield of aquifers. In western Yemen’s Sana’a Basin, the

estimated annual water extraction of 224 million tons exceeds the annual

recharge of 42 million tons by a factor of five, dropping the water table 6

meters per year. World Bank projections indicate the Sana’a Basin—site of

the national capital, Sana’a, and home to 2 million people—will be pumped

dry by 2010.

 

In the search for water, the Yemeni government has drilled test wells in the

basin that are 2 kilometers (1.2 miles) deep—depths normally associated with

the oil industry—but they have failed to find water. Yemen must soon decide

whether to bring water to Sana’a, possibly by pipeline from coastal

desalting plants, if it can afford it, or to relocate the capital. Either

alternative will be costly and potentially traumatic.

 

Israel, even though it is a pioneer in raising irrigation water

productivity, is depleting both of its principal aquifers—the coastal

aquifer and the mountain aquifer that it shares with Palestinians. Israel’s

population, whose growth is fueled by both natural increase and immigration,

is outgrowing its water supply. Conflicts between Israelis and Palestinians

over the allocation of water in the latter area are ongoing. Because of

severe water shortages, Israel has banned the irrigation of wheat.

 

In Mexico—home to a population of 107 million that is projected to reach 140

million by 2050—the demand for water is outstripping supply. Mexico City’s

water problems are well known. Rural areas are also suffering. For example,

in the agricultural state of Guanajuato, the water table is falling by 2

meters or more a year. At the national level, 51 percent of all the water

extracted from underground is from aquifers that are being overpumped.

 

Since the overpumping of aquifers is occurring in many countries more or

less simultaneously, the depletion of aquifers and the resulting harvest

cutbacks could come at roughly the same time. And the accelerating depletion

of aquifers means this day may come soon, creating potentially unmanageable

food scarcity.

 

While falling water tables are largely hidden, rivers that are drained dry

before they reach the sea are highly visible. Two rivers where this

phenomenon can be seen are the Colorado, the major river in the southwestern

United States, and the Yellow, the largest river in northern China. Other

large rivers that either run dry or are reduced to a mere trickle during the

dry season are the Nile, the lifeline of Egypt; the Indus, which supplies

most of Pakistan’s irrigation water; and the Ganges in India’s densely

populated Gangetic basin. Many smaller rivers have disappeared entirely.

 

Since 1950, the number of large dams, those over 15 meters high, has

increased from 5,000 to 45,000. Each dam deprives a river of some of its

flow. Engineers like to say that dams built to generate electricity do not

take water from the river, only its energy, but this is not entirely true

since reservoirs increase evaporation. The annual loss of water from a

reservoir in arid or semiarid regions, where evaporation rates are high, is

typically equal to 10 percent of its storage capacity.

 

The Colorado River now rarely makes it to the sea. With the states of

Colorado, Utah, Arizona, Nevada, and, most important, California depending

heavily on the Colorado’s water, the river is simply drained dry before it

reaches the Gulf of California. This excessive demand for water is

destroying the river’s ecosystem, including its fisheries.

 

A similar situation exists in Central Asia. The Amu Darya—which, along with

the Syr Darya, feeds the Aral Sea—is diverted to irrigate the cotton fields

of Central Asia. In the late 1980s, water levels dropped so low that the sea

split in two. While recent efforts to revitalize the North Aral Sea have

raised the water level somewhat, the South Aral Sea will likely never

recover.

 

China’s Yellow River, which flows some 4,000 kilometers through five

provinces before it reaches the Yellow Sea, has been under mounting pressure

for several decades. It first ran dry in 1972. Since 1985 it has often

failed to reach the sea, although better management and greater reservoir

capacity have facilitated year-round flow in recent years.

 

The Nile, site of another ancient civilization, now barely makes it to the

sea. Water analyst Sandra Postel, in Pillar of Sand, notes that before the

Aswan Dam was built, some 32 billion cubic meters of water reached the

Mediterranean each year. After the dam was completed, however, increasing

irrigation, evaporation, and other demands reduced its discharge to less

than 2 billion cubic meters.

 

Pakistan, like Egypt, is essentially a river-based civilization, heavily

dependent on the Indus. This river, originating in the Himalayas and flowing

westward to the Indian Ocean, not only provides surface water, it also

recharges aquifers that supply the irrigation wells dotting the Pakistani

countryside. In the face of growing water demand, it too is starting to run

dry in its lower reaches. Pakistan, with a population projected to reach 305

million by 2050, is in trouble.

 

In Southeast Asia, the flow of the Mekong is being reduced by the dams being

built on its upper reaches by the Chinese. The downstream countries,

including Cambodia, Laos, Thailand, and Viet Nam—countries with 168 million

people—complain about the reduced flow of the Mekong, but this has done

little to curb China’s efforts to exploit the power and the water in the

river.

 

The same problem exists with the Tigris and Euphrates Rivers, which

originate in Turkey and flow through Syria and Iraq en route to the Persian

Gulf. This river system, the site of Sumer and other early civilizations, is

being overused. Large dams erected in Turkey and Iraq have reduced water

flow to the once “fertile crescent,” helping to destroy more than 90 percent

of the formerly vast wetlands that enriched the delta region.

 

In the river systems just mentioned, virtually all the water in the basin is

being used. Inevitably, if people upstream use more water, those downstream

will get less. As demands continue to grow, balancing water demand and

supply is imperative. Failure to do so means that water tables will continue

to fall, more rivers will run dry, and more lakes and wetlands will

disappear.

 

 

 

 

Version: 7.5.476 / Virus Database: 269.10.25/926 - Release 7/29/2007

11:14 PM

 

 

 

 

[Guest guest]

Texas is working a big desalination project (of both sea water and

brackish water)

 

http://www.beg.utexas.edu/environqlty/desalination01.htm

 

http://www.twdb.state.tx.us/iwt/desal.asp

 

Now if someone were smart enough to build a system that pumped water

from the flooded areas around the country to the drought stricken areas,

we'd not have water worries at all.

 

If we can get a person to the moon, we should be able to do that

 

*Smile*

Chris (list mom)

http://www.alittleolfactory.com

 

David Lambert wrote:

> Came across this, makes you wonder...

>

> WATER TABLES FALLING AND RIVERS RUNNING DRY

>

> " http://www.earth-policy.org/Books/Seg/PB2ch03_ss2.htm " http://www.earth-poli

> cy.org/Books/Seg/PB2ch03_ss2.htm

>

> Dave

>

[Guest guest]

And you would think the actual cost of doing something like that wouldn't

outweigh the benefits...

 

As for me... I would love it if someone decided to siphon off some of the

" humidity " from around here in that... TAKE the DANG SKEETERS WITH EM. If

we're gonna go fer broke, why not create a machine that would suck the water

right outta the air and put it where it's needed most.. OH yeah. That's

called a rain shower... He hehehehehe..

 

haud desiderium

sieze dies

Orbis terrarum est meus oyster

vos mos non subsisto mihi

EGO sum a comic indoles

 

Jennifer Janek-Markey

Soapywench

 

 

 

_____

 

On Behalf Of Christine Ziegler

Tuesday, July 31, 2007 12:41 PM

 

Re: OT: Environmental note, water is drying up

 

 

 

Texas is working a big desalination project (of both sea water and

brackish water)

 

http://www.beg. <http://www.beg.utexas.edu/environqlty/desalination01.htm>

utexas.edu/environqlty/desalination01.htm

 

http://www.twdb. <http://www.twdb.state.tx.us/iwt/desal.asp>

state.tx.us/iwt/desal.asp

 

Now if someone were smart enough to build a system that pumped water

from the flooded areas around the country to the drought stricken areas,

we'd not have water worries at all.

 

If we can get a person to the moon, we should be able to do that

 

*Smile*

Chris (list mom)

http://www.alittleo <http://www.alittleolfactory.com> lfactory.com

 

David Lambert wrote:

> Came across this, makes you wonder...

>

> WATER TABLES FALLING AND RIVERS RUNNING DRY

>

> " http://www.earth- <http://www.earth-policy.org/Books/Seg/PB2ch03_ss2.htm>

policy.org/Books/Seg/PB2ch03_ss2.htm " http://www.earth-

<http://www.earth-poli> poli

> cy.org/Books/Seg/PB2ch03_ss2.htm

>

> Dave

>