what is water footprint

8/13/2019 What is Water Footprint

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What is Water Footprint

Virtual water is the volume of water (greenand/or blue) used to produce a good or service(Allan, 1993, 2003).

Water Footprint is the total volume of water(green and blue) that is used to produce thegoods and services consumed by an individual orcommunity (about 70% for food) (Hoekstra andHung, 2002).

When and where the water was used: a waterfootprint includes a temporal and spatialdimension.


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The water footprint of a product

Green water footprint

volume of rainwater evaporated or incorporated into product.

Blue water footprint

volume of surface or groundwater evaporated,

incorporated into product or returned to other catchment or the

sea.

Grey water footprint

volume of polluted water.


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Direct water footprint Indirect water footprint

Green water footprint Green water footprint

Blue water footprint Blue water footprint

Grey water footprint Grey water footprint

Water

consumption

Water

pollution

[Hoekstra et al., 2011]

Return flow

Water withdrawal

The traditional

statistics

on water use

Components of a water footprint


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Water foot print various..

Global average water footprint: 70 litres for one apple

(100 gms)

One glass of apple juice (200 ml) costs about 190 litres of

water

Global average water footprint: 1300 litres of water for 1

kg of wheat

Global average water footprint: 2700 litres for 1 cotton

shirt.

1 kg of final cotton textile, one requires 11,000 litres of

water


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Water foot print various..

Global average water footprint: 3900 litres for 1 kg of

chicken meat

Global average water footprint: 15500 litres of water

per kg of beef.


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the total volume of water appropriated for the production of the

goods and services consumed.

equal to the sum of the water footprints of all goods and servicesconsumed.

dimensions of a water footprint

volume

where and when type of water use: green, blue, grey

Water footprint of a consumer


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total amount of water that is used to produce the goods and services

consumed by the inhabitants of the nation.

two components: internal water footprint inside the country.

external water footprint in other countries.

Water footprint of national consumption

water footprint of national consumption =

water footprint within the nation + virtual water import

virtual water export


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Consumption

Export

Prod

uction

Import

Internal

waterfootprint

External

waterfootprint

WF of

nationalconsumpt.

Water use

for export

Virtual water

import for re-

export

Virtual

water

export

+

+

=

=

WF

within

nation

Virtual

water

import

++

= =

Virtual

water

budget

+

+ =

=

National water use accounting framework

The traditional

statistics on

water use, but

then limited to

withdrawals


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Country/region National water footprint (Gm3/year)

from the

perspective of

production

from the

perspective of

consumption

Australia 91 27

Canada 123 63

China 893 883

Egypt 59 70EU25 559 744

India 1013 987

Japan 54 146

Jordan 1.8 6.3

USA 750 696

[Hoekstra & Chapagain, 2008]

WF of national

consumption

WF within

a nationTraditional statistics

on water use, but

then restricted towater withdrawal


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Game-Four Countries

Country A Country B Country C Country D

Climate Temperate

Mediterran

ean

(Sub)tropic

al wet

(Sub)tropica

l dry

Development

status Developed Developed Developing Developing

Water

endowment Humid Semi-arid Humid Semi-arid

Water

productivity High Very High Very low Low


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Three Roles

Head of State, coordinating decisions but

mostly interested in the national economy.

Minister of Environment, responsible for

allocating water in a sustainable manner.

Minister of Trade & Foreign Affairs,

responsible for negotiating with other

countries and relation with other countries


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Decisions to be taken

Allocate the available green water resources (broadly

speaking rain water, technically evaporation

flows) and blue water resources (ground/surface

water flows) over the five sectors of economy andthe environment.

Decide, per sector, how the produced commodities

are distributed over consumption and export.

Exchange the exports for other commodities.

Imported commodities are used for consumption


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The Five Sectors

Food grains

Vegetables & fruits

Meat & dairy products

Cotton

Energy crops


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What did we learn?

Global dimension of watertrade in water-intensive

products.

Comparative advantage.

Trans-border water footprint; reduce footprint through trade.

National water self-sufficiency versus dependency.

Conflict between different sectors.

Conflict water for economy versus water for nature.

Different water intensities of various commodities. Green versus blue water.


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Water productivities (kg/m3)

Green water Country A Country B Country C Country DFood grains 0.4 0.2 0.04 not applicableVegetables &fruits 0.5 0.8 0.3 not applicableMeat & dairy products 0.01 0.06 0.002 0.01Cotton not applicable 0.06 0.03 not applicableEnergy crops 0.5 0.3 0.15 not applicableBlue water Country A Country B Country C Country DFood grains 0.6 0.3 0.06 0.05Vegetables &fruits 0.8 5 0.3 1.1Meat & dairy products 0.06 0.03 0.003 0.005Cotton not applicable 0.1 0.03 0.1Energy crops 0.5 0.5 0.3 0.1


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Comparative advantages

Green water Country A Country B Country C Country DFood grains + - 0 not applicableVegetables &fruits - - + not applicableMeat & dairy products - + - +Cotton

not applicable

-

+

not applicable

Energy crops + - + not applicableBlue water Country A Country B Country C Country DFood grains + - 0 -Vegetables &fruits - + - +Meat & dairy products + - - -Cotton not applicable - 0 +Energy crops - - + -

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