Water security of nations

1
NATO workshop Yerevan, 18-22 October 2007
Water security of nations how international trade
affects national water scarcity and dependency
Arjen Hoekstra University of
Twente www.waterfootprint.org
2
Overview of presentation

• Introduction
• The water needs of goods and services
• International virtual water flows
• Saving water through trade
• Water footprints of nations
• Water dependency of nations

3
The concept of virtual water

• Virtual water is the water embodied in a
  product, not in real sense, but in virtual sense.
  It refers to the water needed for the production
  of the product.
• Global trade in goods and services brings
• along global trade in virtual water

compare embodied energy
4
Assessing the virtual water contentof products

• Virtual water content of a crop
• Crop water requirement (m3/ha) / Crop yield
  (ton/ha)
• Virtual water content of an animal
• Sum of water for feed, drinking and servicing
• Virtual water content of a crop or livestock
  product
• Distribute the virtual water content of the root
  product over its derived products

5
Crop water requirement

• Calculate reference crop evapotranspiration ET0
  (mm/day)
• e.g. Penman-Monteith equation
• Calculate crop evapotranspiration Etc (mm/day)
• Etc ET0 ? Kc where Kc crop coefficient
• Calculate crop water requirement CWR (m3/ha)
• CWR S Etc accumulate over growing period

6
Virtual water content of products
7
40 litres of water for 1 slice of bread
8
1500 litres of water per kg refined sugar
9
2500 litres of water for 1 cotton shirt
10
1 egg 135 litres water
11
2400 litres of water for 1 hamburger
12
10 litres of water for 1 sheet of A4-paper
13
140 litres of water
14
Assessing virtual water flows

• Virtual water trade flow (m3/yr)
• Trade volume (ton/yr) ? Virtual water content
  (m3/ton)
• Global trade data
• UN Statistics Division, New York
• FAOSTAT, FAO, Rome

15
International virtual water flows (1997-2001)
16 of global water use!

• Chapagain Hoekstra, 2004

16
Contribution of various agricultural productsto
the total sum of international virtual water flows
17
National virtual water balances
18
Regional virtual water balances(only
agricultural trade)
Arrows show trade flows gt10 Gm3/yr
19
Water saving through trade

• National water saving
• A water scarce nation can save water by importing
  a water-intensive commodity instead of producing
  it domestically.
• Global water saving
• International trade can save water globally
• if a water-intensive commodity is traded
• from an area with high to an area with low water
  productivity.
• - global water use efficiency

20
Global water savingthrough rice trade from USA
to Mexico
21
Global water lossthrough rice trade from
Thailand to Indonesia
22
Global water saving
The total global water saving as a result of
the international trade of agricultural products
352 Gm3/yr (period 1997-2001) Equivalent
to 6 of water use in agriculture in the world !
Chapagain, Hoekstra Savenije, 2005
23
Water use efficiency at different levels
24
? The water footprint of a nation is the total
amount of water that is used to produce the goods
and services consumed by the inhabitants of the
nation.
25
? Consumption is partly related to domestic
resource use, and partly to resource use outside
the country borders ? internal external water
footprint.
26
? The water footprint consists of three
componentsblue wf green wf grey wf
27
? The blue water footprint is the volume of
freshwater that evaporated from the global blue
water resources (surface water and ground water)
to produce the goods and services consumed by the
individual or community. The green water
footprint is the volume of water evaporated from
the global green water resources (rainwater
stored in the soil as soil moisture). The gray
water footprint is the volume of polluted water
that associates with the production of all goods
and services for the individual or community. The
latter has been calculated as the volume of water
that is required to dilute pollutants.
28
? National water footprint national water
use virtual water import virtual water
export
29
(No Transcript)
30
Water footprint per capita
Chapagain Hoekstra, 2004
31
Water footprint per capita
Chapagain Hoekstra, 2004
32
Major determinants of a water footprint

• Consumption characteristics
• Consumption volume
• Consumption pattern
• Production circumstances
• Climate evaporative demand at place of
  production
• Agricultural practice water use efficiency

33
? case studiesNetherlands, Morocco, China,
India, Japan
34
Global water footprint of The Netherlands
82 of the Dutch water footprint is outside its
own borders
35
Water footprint of Morocco
15 of Moroccos water footprint is outside its
own borders
36
Water saving in Morocco through trade
Use of domestic water 37 Gm3/yr National saving
due to import 28 Gm3/yr Water use if import
would stop and all products would be produced
domestically 65 Gm3/yr !
37
Water footprint of China
38
Virtual water transfers in China
52 Gm3/yr
39
Virtual water trade vs.real interbasin water
transfers

• Current water use in China 550 billion m3/yr
• Proposed water transfers
• from South to North China
• 40-50 billion m3/yr
• Alternative
• Stop the use of water in the North for making
  products that are traded to the South

40
South to North water transfer in China
41
Water footprint of India
42
Water footprint of Japan
43
Water footprint of EUs cotton consumption blue
water
44
Water footprint of EUs cotton consumption green
water
45
Water footprint of EUs cotton consumption grey
water
46
Water footprint of EUs cotton consumption blue
green grey water
47
Water dependency of nations

• Many countries have net import of water in
  virtual form and a significant external water
  footprint
• most of Europe
• North Africa
• Middle East
• Japan
• Mexico

48
Virtual water Virtual waterexporter importers
Middle East and North Africa
Dependency on virtual water import 19 33 15
74 73 17 67

• Syria Egypt
• Algeria
• Morocco
• Israel
• Jordan
• Tunesia
• Lebanon

49
below a threshold of 1500 m3/cap/yr, the demand
for cereal import increases exponentially with
decreasing water resources
Yang et al, 2003
50
Conclusions (1)

• Water saving through trade
• Import of water in virtual form as a source of
  water has not yet been exploited by many
  water-scarce-countries.
• Current global trade reduces water use in
  agriculture by 6.
• Export from water-scarce nations can best focus
  on products with high water productivity
  (Euro/m3).

51
Conclusions (2)

• Water dependency
• Most countries in EU, North Africa and Middle
  East are dependent on water resources in other
  parts of the world.
• Water has become a geopolitical resource, like
  oil.
• Local consumption, global impact
• Consumers cause water impacts all over the world
  without paying.

52
Globalization water the key questions

• From the national perspective
• ? Is import of water in virtual form a solution
  to a water-scarce country?
• ? What is the risk of becoming water dependent?
• From the global perspective
• ? Is virtual water trade a mechanism to increase
  global water efficiency?
• ? What is the risk of shifting off the
  environmental impacts?

53
data and publicationswww.waterfootprint.org