|
INTERNATIONAL YEAR OF FRESHWATER
2003
Global Water Withdrawal and Consumption
Use of Freshwater by continents
Freshwater use is
partly based on several socio-economic development factors, i ncluding
population, physiography, and climatic characteristics. This
graphic illustrates freshwater use from 1900 to 2000 for the
world's major regions, and projects freshwater use for 2000 to
2025.
- Annual global
freshwater withdrawal has grown from 3 790 km3 (of which
consumption accounted for 2 070 km3 or 61%) in 1995, to ~4 430
km3 (of which consumption accounted for 2 304 km3 or 52%) in
2000 (Shiklomanov, 1999).
- In 2000, about
57% of the world's freshwater withdrawal, and 70% of its cons
 umption,
took place in Asia, where the world's major irrigated lands
are located (UNESCO, 1999).
- In the future,
annual global water withdrawal is expected to grow by about
10-12% every 10 years, reaching approximately 5 240 km3 (or an
increase of 1.38 times since 1995) by 2025. Water consumption
is expected to grow at a slower rate of 1.33 times (UNESCO,
1999).
- In the coming
decades, the most intensive growth of water withdrawal is
expected to occur in Africa and South America (increasing by
1.5-1.6 times), while the smallest growth will take place in
Europe and North America (1.2 times) (Harrison and Pearce,
2001; Shiklomanov, 1999; UNESCO, 1999).
Evolution of Global Water Use and Industrial and Domestic
Consumption Compared with Evaporation from Reservoirs.
 Throughout
the 20th century, global water use has increased in the
agricultural domestic and industrial sectors. Evaporation from
reservoirs has increased at a slower rate. Projections indicate
that both global water use and evaporation will continue to
increase.
The agricultural sector is by far the biggest user of
freshwater:
- In the United
States, agriculture accounts for some 49% of the total
freshwate
 r
use, with 80% of this volume being used for irrigation (Shiklomanov,
1999).
- In Africa and
Asia, an estimated 85-90% of all the freshwater used is for
agriculture (Shiklomanov, 1999).
- According to
estimates for the year 2000, agriculture accounted for 67% of
the world's total freshwater withdrawal, and 86% of its
consumption (UNESCO, 2000).
- By 2025,
agriculture is expected to increase its water requirements by
1.2 times, industry by 1.5 times, and domestic consumption by
1.8 times (Shiklomanov, 1999).
- The world's
irrigation areas totalled approximately 253 million hectares
in 1995. By 2010, they are expected to reach about 290 million
hectares, and by 2025 about 330 million hectares (Shiklomanov,
1999).
- By the year
2000, an estimated 15% of the world's cultivated lands were
irrigated for food crops, accounting for almost half of the
value of global crop production (UNESCO, 1999).
In the industrial sector:
In the industrial
sector, the biggest share of freshwater is stored in reservoirs
and dams for
 electrical
power generation and irrigation. However, the volume of water
evaporated from reservoirs is estimated to exceed the combined
freshwater needs of industry and domestic consumption. This
greatly contributes to water losses around the world, especially
in the hot tropical regions (UNESCO, 1999).
Industrial uses
account for about 20% of global freshwater withdrawals. Of this,
57-69% is used for hydropower and nuclear power generation,
30-40% for industrial processes, and 0.5-3% for thermal power
generation (Shiklomanov, 1999).
Domestic water use is related to the quantity of water available
to populations in cities and towns:
- People in
developed countries on average consume about 10 times more
water daily than those in developing countries. It is
estimated that the average person in developed countries uses
500-800 litres per day (300 m3 per year), compared to 60-150
litres per day (20 m3 per year) in developing countries
(UNESCO, 2000).
- In large cities
with a centralised water supply and an efficient canalisation
system, domestic consumption does not usually represent more
than 5-10% of the total water withdrawal (intake) (UNESCO,
2000).
- Water withdrawal
in large cities is estimated at 300-600 litres per person per
day, while small cities have a water withdrawal of ~100-150
litres, and consumption can reach 40-60% of the total water
intake (UNESCO, 2000).
- In developing
countries in Asia, Africa and Latin America, public water
withdrawal represents just 50-100 litres per person per day.
In regions with insufficient water resources, this figure may
be as low as 20-60 litres per day (UNESCO, 2000).
Managing water
resources using an integrated river basin management approach is
the most sustainable way of ensuring ecosystem integrity. In
this respect, there is a need to consider the economic value of
freshwater ecosystems, including their fisheries, wildlife
habitats, recreation and natural flood control benefits.
Water Supply and Sanitation Coverage
 The
supply of safe drinking water and the provision of sanitation
are management issues that raise concerns of inequitable service
provision, particularly in developing countries. This graphic
shows water supply and sanitation coverage in urban and rural
areas, and compares global water supply and sanitation coverage
with that of developing countries.
Water Supply Highlights, from The Global Water Supply and
Sanitation Assessment 2000
- The
percentage of people served with some form of improved
water supply rose from 79% (4.1 billion people) in 1990
to 82% (4.9 billion) in 2000. Between 1990 and 2000,
approximately 816 million additional people gained
access to water supplies - an improvement of 3%.
- Two of
every five Africans lack access to an improved water
supply. Throughout Africa, rural water services lag far
behind urban services.
- During the
1990s, rural water supply percentage coverage increased
while urban coverage decreased - although the number of
people who lack access to water supplies remained about
the same.
- In Africa,
Asia, Latin America and the Caribbean, nearly 1 billion
people in rural areas have no access to improved water
supplies.
- To achieve
the 2015 targets in Africa, Asia, Latin America and the
Caribbean, water supplies will have to reach an
additional 1.5 billion people.
Source: WHO/UNICEF, 2000 |
During the 1990s,
the greatest reduction in per capita water supply was in Africa
(by 2.8 times), Asia (by two times), and Latin America and the
Caribbean (by 1.7 times).
The lack of access
to safe drinking water and sanitation is directly related to
poverty, and in many cases to the inability of governments to
finance satisfactory water and sanitation systems. The direct
and indirect human costs of these failings are enormous,
including widespread health problems, heavy labour (particularly
for women, who are forced to travel long distances to obtain
water for their families), and severe limitations for economic
development (Gleick, 1995).
Sanitation Highlights, from The Global Water Supply and
Sanitation Assessment 2000
- The
proportion of people with access to excreta disposal
facilities increased from 55% (2.9 billion people) in
1990 to 60% (3.6 billion) in 2000. Between 1990 and
2000, approximately 747 million additional people gained
access to sanitation facilities - although the number of
people who lack access to sanitation services remained
roughly the same.
- At the
beginning of 2000, two-fifths of the world's population
(2.4 billion people) lacked access to improved
sanitation facilities. The majority of these people live
in Asia and Africa, where fewer than half of all Asians
have access to improved sanitation.
- Sanitation
coverage in rural areas is less than half of that in
urban locations, even though 80% of those lacking
adequate sanitation (2 billion people) live in rural
areas - some 1.3 billion in China and India alone.
- In Africa,
Asia, Latin America and the Caribbean, nearly 2 billion
people in rural areas have no access to improved
sanitation facilities.
- To achieve
2015 sanitation targets in Africa, Asia, Latin America
and the Caribbean, an additional
2.2 billion
people will have to be provided with sanitation
facilities.
- Polluted
water is estimated to affect the health of more than 1.2
billion people, and to contribute to the death of an
average 15 million children every year. In 1994, WHO
estimated the number of people without access to clean
drinking water at 1.3 billion. By 2000, nearly 1.2
billion people lacked access to clean water, while 2.4
billion lacked access to adequate sanitation services.
Source: WHO/UNICEF, 2000. |
In developing
countries, water delivery systems are plagued by leakages,
illegal connections and vandalism, while precious water
resources are squandered through greed and mismanagement. The
World Bank recently estimated that US $600 billion is required
to repair and improve the world's water delivery systems (UNCSD,
1999).
The water supplies
available to European populations for that period decreased only
by 16% (WHO/UNICEF, 2000).
Improved water and
sanitation facilities, on the other hand, bring valuable
benefits for both social and economic development and poverty
alleviation (WHO/UNICEF 2000).
Source:
http://www.unep.org/vitalwater/
|
