Copyright © 2002 Earth Policy Institute
Water Scarcity Spreading
Water scarcity may be the most underestimated resource issue facing the world today. As world water demand has more than tripled over the last half-century, signs of water scarcity have become commonplace. Some of the more widespread indicators are rivers running dry, wells going dry, and lakes disappearing.
Among the rivers that run dry for part of the year
are the Colorado in the United States, the Amu Darya in Central Asia,
and the Yellow in China. China's Hai and Huai rivers have the same problem
from time to time, and the flow of the Indus River--Pakistan's lifeline--is
sometimes reduced to a trickle when it enters the Arabian Sea.
The Colorado River, the largest in the southwestern United States, now
rarely makes it to the sea. As the demand for water increased over the
years, diversions from the river have risen to where they now routinely
drain it dry.
A similar situation exists in Asia, where the Amu Darya--one of the two
rivers feeding the Aral Sea--now is dry for part of each year. With the
sharp decline in the amount of water delivered to the Aral Sea by the
Amu Darya, the sea has begun to shrink. There is a risk that the Aral
could one day disappear entirely, existing only on old maps.
China's Yellow River, the northernmost of its two major rivers, first
ran dry for a few weeks in 1972. Since 1985, it has failed to make it
to the Yellow Sea for part of almost every year. Sometimes the river does
not even reach Shandong, the last province it flows through en route to
the sea. As water tables have fallen, springs have dried up and some rivers
have disappeared entirely. China's Fen River, the major watercourse in
Shanxi Province, which once flowed through the capital of Taiyuan and
merged with the Yellow, no longer exists.
Another sign of water scarcity is disappearing lakes. In Central Africa,
Lake Chad has shrunk by some 95 percent over the last four decades. Reduced
rainfall, higher temperatures, and some diversion of water from the streams
that feed Lake Chad for irrigation are contributing to its demise. In
China, almost 1,000 lakes have disappeared in Hebei Province alone.
Water tables are falling in several of the world's key farming regions,
including under the North China Plain, which produces nearly one third
of China's grain harvest; in the Punjab, which is India's breadbasket;
and in the U.S. southern Great Plains, a leading grain-producing region.
Water shortages now plague almost every country in North Africa and the
Middle East. Algeria, Egypt, Iran, and Morocco are being forced into the
world market for 40 percent or more of their grain supply. As population
continues to expand in these water-short nations, dependence on imported
grain is rising.
Iran, one of the most populous countries in the Middle East, with 70 million
people, is facing widespread water shortages. In the northeast, Chenaran
Plain--a fertile agricultural region to the east of Mashad, one of Iran's
largest and fastest-growing cities--is fast losing its water supply. Wells
drawing from the water table below the plain are used for irrigation and
to supply water to Mashad. The latest official estimate shows the water
table falling by 8 meters in 2001 as the demand for water far outstrips
the recharge rate of aquifers.
Falling water tables in parts of eastern Iran have caused many wells to
go dry. Some villages have been evacuated because there is no longer any
accessible water. Iran is one of the first countries to face the prospect
of water refugees--people displaced by the depletion of water supplies.
In Yemen, a country of some 19 million people, water tables are falling
everywhere by 2 meters or more a year. In the basin where the capital
Sana'a is located, extraction exceeds recharge by a factor of five, dropping
the water table by 6 meters (about 20 feet) a year. Recent wells drilled
to a depth of 2 kilometers (1.3 miles) failed to find any water. In the
absence of new supplies, the Yemeni capital will run out of water by the
end of this decade.
Another way of looking at water security is the amount of water available
per person in a country. In 1995, 166 million people lived in 18 countries
where the average supply of fresh water was less than 1,000 cubic meters
a year--the amount deemed necessary to satisfy basic needs for food, drinking
water, and hygiene. By 2050, water availability per person is projected
to fall below the 1,000-cubic-meter benchmark in some 39 countries. By
then, 1.7 billion people will in effect be suffering from hydrological
poverty.
At some point, the combination of aquifer depletion and the diversion
of irrigation water to cities will likely begin to reduce the irrigated
area worldwide. Data compiled by the U.N. Food and Agriculture Organization,
based on official data submitted by governments, show irrigated area still
expanding. For example, between 1998 and 1999, the last year for which
global data are available, irrigated area grew from 271 to 274 million
hectares. (See Figure.) This reported 1-percent growth would be reassuring,
but it appears to be overstated since governments are much better at gathering
data on new irrigation projects than on irrigation reductions as water
is diverted to cities or aquifers are depleted. It is quite possible that
the historical growth in world irrigated area has come to a halt, and
the area could even be declining.
Copyright © 2002 Earth Policy Institute
OTHER INFORMATION FROM THE EARTH POLICY INSTITUTE
Rising Temperatures and Falling Water Tables Raising Grain Prices
Water Deficits Growing in Many Countries
World Grain Harvest Falling Short by 54 Million Tons: Water Shortages Contributing to Shortfall
Worsening Water Shortages
Threaten China's Food Security
Lester R. Brown, Janet Larsen, and Bernie Fischlowitz-Roberts, The Earth Policy Reader (New York: W.W. Norton & Company, 2002).
Lester R. Brown, Chapter 2: "Signs of Stress: Climate and Water," in Eco-Economy: Building an Economy for the Earth (W.W. Norton & Company, 2001).
LINKS
AQUASTAT, global information system of water and agriculture
from the Land and Water Development Division of the U.N. Food and Agriculture
Organization
http://www.fao.org/ag/agl/aglw/aquastat/main/index.stm
International Water Management Institute
http://www.cgiar.org/iwmi
The World's Water
http://www.worldwater.org
United Nations Environment Programme, UNEP Freshwater
Site
http://freshwater.unep.net
Worldwatch Institute, Water Mini Site
http://www.worldwatch.org/taxonomy/term/102