Abundance
and Scarcity
Water abounds on Earth
but only a minute part of it is accessible to man.
Freshwater represents only
3% of all water resources
on the planet. Over half of it
is in the shape of ice, and more
often than not, in inhospitable
regions. Groundwater, which
makes up a third of all
freshwater, is often difficult
to access. Surface freshwater
– lakes and rivers – can more
easily be put to use by man.
The distribution of
freshwater on Earth
Nevertheless, globally
Variations in freshwater
speaking, there is no lack
stocks are to a great
of water resources: annually, extent linked to extremely
an estimated quarter of the
unequal rainfalls in
world’s “usable” freshwater
different regions. Certain
stock is extracted. However, it
is its highly unequal distribution
around the planet that is a
cause for concern. In certain
regions, where resources
represent less than 500m3 per
inhabitant per year (for all
uses, agricultural, industrial
and personal), there is already
a shortage. Other areas, on the
other hand, are regularly hit by
excessive rainfalls that cause
disasters.
mountainsides that are exposed
to ocean humidity in tropical
areas can receive up to 12m of
water per year, whereas desert
regions sometimes go without
rain for several years…
1 The Nile: a vital, readily available
freshwater source in the heart of a
particularly dry region.
2 Domestic water supply in Niger.
In the Sahel, water shortage
sometimes obliges women to walk
up to 60km to fetch water for their
families’ needs.
3 Arid and semi-arid regions, which
represent 30% of all land, contain
only 2.5 % of the freshwater on
the planet. The Sur Lípez desert in
Bolivia.
1 to 2%
Nearly 1/3
More than 2/3
freshwater on the surface and in the atmosphere
1
5 Groundwater aquifers, which
represent much greater volumes
than rivers and streams, can be
accessed through wells or springs
that provide water, like here on
Réunion Island.
6 Seas and oceans make up nearly
97% of the planet’s water resources.
7 The vast majority of freshwater
is stored as ice, which is formed by
snowfalls over centuries. Astrolabe
Glacier near the South Pole,
Antarctica.
4 Glaciers supply a considerable
percentage of the water resources
of many inhabited and cultivated
valleys. Cordillera Real, Bolivia.
freshwater under ground
freshwater in the form of ice
2
3
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4
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Water at the Heart of Science
2
Vital
Water
At the basis of life
freshwater is crucial to man.
Managing this resource is clearly a key factor for human development.
To eat, bathe, produce
energy… Water is essential
to human survival and
well-being, and central
to economic and societal
development. Agriculture
consumes the greatest part
of it, representing an average
70% of all water extraction
worldwide, compared to 20%
for industry and only 10%
for household consumption.
Rivers, lakes and streams also
form an indispensible means
of communication between
people, allowing economic,
cultural and social exchange
from one shore to another,
up- and downstream.
Today, with the
development of human
activities (agriculture,
industry) and demographic
growth, consumption is
increasing and intensifying.
The pressure on water
resources is therefore
constantly growing stronger,
and sometimes leads to conflict
between users.
Recently, the United
Nations (UN) alerted the
world to a major challenge
for the future of mankind:
supplying in the growing
need for water which is
vital to economic and social
development, without putting
this precious resource at risk.
1 Water in favelas is stored in
rooftop reservoirs. It is brought
there by parallel networks or tanker
lorries, since official distribution
networks are scarce.
Rio de Janeiro, Brazil.
2 Man cannot survive more than 3
days without drinking.
3 In many poor countries, people
still do their washing in streams.
Niger River, Mali.
4 Chooz nuclear power station on
the Meuse. Industry and energy
production represent 28% of all
water consumption in France (the
worldwide average is 10%). This
rate is much higher in industrialised
countries than in developing
countries of the Global South.
2
1
5 40% of the world’s agricultural
production is made possible by
irrigation. A farmer uses a calabash
to water onion plants in
Burkina Faso.
6 Waterways are used to transport
goods from where they are
produced to where they are sold.
Floating market, Damnoen Saduak,
Thailand.
7 Drought, which causes famine,
is a major obstacle to the
development of many countries in
the Global South. This quinoa plant
survived the drought in the Bolivian
Altiplano.
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Water at the Heart of Science
3
Available Water
Accessible Water?
One billion people
in the world – in other words 1 out of 7 inhabitants – have no access
to drinking water or sanitation. Most of them live in large cities in developing
countries of the South.
Around the world, countries
that suffer from water
scarcity are often also those
where the inhabitants find
it the hardest to come
by drinking water and
sanitation, particularly in
the Sahel or the Middle East.
But the presence of water
in sufficient quantities does
not always guarantee that
populations have access to
quality water and sanitation
facilities, as in Central Africa
or certain Asian countries.
This situation is the result
of insufficient government
investment in infrastructures
to process and dispatch
water to inhabited areas.
Critical situation
Chronic shortage
Stressed
Vulnerable
0
2 500
500
10 000
1 000
40 000
1 700
> 40 000
Renewable freshwater supply by country,
in m3/year/inhabitant.
2 500
Source : World Ressources Institute, 2010
Proportion of the population (by country) supplied with drinking water.
Access to water is
defined as having
a water supply
point available
within 200m from
a dwelling.
Over 95%
Between 83% and 95%
Worldwide average: 83%
Between 65% and 83%
Less than 65%
Data not available
1 - As defined by the World Health Organisation (WHO) and Unicef: piped water supply to the dwelling,
a public tap/standpipe, a tube well/borehole, a protected dug well, a protected spring,
or a rainwater tank.
Sources: World Health Organisation (OMS) and Unicef, 2008.
Water at the Heart of Science
4
Resource
at Risk
Together with climate
change and a growing world population – an expected 9 billion people in 2050 –
pressure on this resource is intensifying by the day.
Various factors can reduce the
quantity and quality of water
that is available and accessible
to humans; the first of these
is human activity. Usable
water resources in rivers, lakes
and groundwater aquifers
are replenished by rainwater,
melting snow and glaciers. If
the amount extracted exceeds
the recharge rates, the water
cannot be renewed. And since
1950, freshwater extraction has
increased threefold.
Deterioration of ecosystems
also disturbs the water cycle.
Deforestation and the claiming
of new land for farming
purposes reduce the soil’s
absorption capacity and, by
consequence, the renewal of
groundwater.
Added to this, pollution –
particularly from agriculture
and industry – is a serious
threat to water quality.
Climate change accentuates
these effects: experts foresee
more severe droughts and more
frequent floods in many parts of
the planet. These inequalities
are increasing between regions
with too little water, and those
with too much.
1 More than 1.2 billion people
are affected by desertification
(deterioration of the soil due for
instance to drought). A cause that
is too often neglected, despite the
fact that this phenomenon impacts
nearly one third of all emerged land
and all continents.
2 Due to global warming,
researchers fear that rainfall
patterns will be disturbed and thus
accentuate arid but also very humid
climates.
3 Tree roots and plant cover in
general allow water to infiltrate
the soil instead of letting large
quantities run down into valleys.
Because of deforestation, the soil is
no longer retained, but gets washed
away with the water.
4 The melting of tropical glaciers,
particularly in the Himalayas, will
cause a temporary increase in river
flow, followed by an inevitable
decrease once the glaciers have
disappeared.
5 Certain countries build long
irrigation channels to transport
water to fields. A channel in
Morocco.
6 Certain industries consume
massive amounts of water, for
instance paper factories.
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Water at the Heart of Science
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