Part I A comprehensive introduction to water footprint accounting This is a summary of the Water Footprint Assessment Manual Earthscan 2011 by Maite Martínez Aldaya Strengthening National Capacities for Sustainable Resource Management in Latin America and the Caribbean CILCA 2011 COATZACOALCOS, Mexico April 7th, 2011
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Part I A comprehensive introduction to water footprint accounting This is a summary of the Water Footprint Assessment Manual Earthscan 2011 by Maite Martínez.
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Part IA comprehensive introduction to water
footprint accountingThis is a summary of the Water Footprint
Strengthening National Capacities for Sustainable Resource Management in Latin America and the
Caribbean CILCA 2011
COATZACOALCOS, Mexico April 7th, 2011
The water footprint concept
► The WF is an indicator of water use that looks at both direct and indirect water use of a consumer or producer.
► measured in terms of water volumes consumed (evaporated or otherwise not returned) or polluted per unit of time.
► geographically and temporally explicit indicator.
► can be calculated for a process, a product, a consumer, group of consumers (e.g. municipality, province, state or nation) or a producer (e.g. a public organization, private enterprise).
[Hoekstra et al., 2011]
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 traditionalstatistics
on water use
The water footprint components
Water footprint sustainability assessment
Water footprint accounting
Water footprint response
formulation
Setting goalsand scope
Phase 1 Phase 2 Phase 3 Phase 4
[Hoekstra et al., 2011]
Water footprint assessment
Water footprint unit
• WF of a process: water volume per unit of time.When divided over the quantity of product that results from the process, it can also be expressed as water volume per product unit.
• WF of a product: water volume per product unit. Examples:
o water volume per unit of mass
o water volume per unit of money
o water volume per piece
o water volume per unit of energy (food products, fuels)
• WF of a consumer or business and WF within an area: water volume per unit of time. The water footprint of a community of consumers can also be expressed in terms of water volume per unit of time per capita.
[Hoekstra et al., 2011]
The water footprintof a product
► the volume of fresh water used to produce the product, summed over the various steps of the production chain.
► when and where the water was used:a water footprint includes a temporal and spatial dimension.
Water footprint of a product
[Hoekstra et al., 2011]
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.
[Hoekstra et al., 2011]
Water footprint of a product
Grey water footprint
• volume of polluted freshwater that associates with the production of a product in its full supply-chain.
• calculated as the volume of water that is required to assimilate pollutants based on ambient water quality standards.
[Hoekstra et al., 2011]
Water footprint of products
1 kg wheat 1 m3 water
1 kg rice 3 m3 water
1 kg milk 1 m3 water
1 kg cheese 5 m3 water
1 kg pork 5 m3 water
1 kg beef 15 m3 water
global averages
[Hoekstra & Chapagain, 2008]
[Hoekstra & Chapagain, 2008]
Food► 1300 kg of grains
(wheat, oats, barley, corn, dry peas, soybean, etc)► 7200 kg of roughages
(pasture, dry hay, silage, etc)
Water► 24000 litres for drinking► 7000 litres for servicing.
The water footprint of a cow
99%
1%
[Hoekstra & Chapagain, 2008]
Water footprintof a consumer
► 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 services consumed.
► dimensions of a water footprint• volume• where and when• type of water use: green, blue, grey
Water footprint of a consumer
[Hoekstra et al., 2011]
Indirect WF Direct WF
bluewateruse
greywater
Farmer RetailerFood
processer
Virtualwaterflow
Virtualwaterflow
Virtualwaterflow
greenandbluewateruse
bluewateruse
greywater
greywater
Consumer
bluewateruse
greywater
[Hoekstra et al., 2011]
Water footprint of a consumer
► 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 within the nation + virtual water import
– virtual water export
Water footprint of national consumption
[Hoekstra et al., 2011]
Consumption
ExportP
rodu
ctio
n
Impo
rt
Internalwater
footprint
External water
footprint
WF of national
consumpt.
Water usefor export
Virtual water import for re-
export
Virtualwaterexport
+
+
=
=
WFwithinnation
Virtualwaterimport
++
= =
Virtual water
budget
+
+ =
=
The traditionalstatistics on
water use, butthen limited towithdrawals
[Hoekstra et al., 2011]
National water use accounting framework
International virtual water flows
Virtual water flow (m3/yr) = Trade volume (ton/yr) Product water footprint (m3/ton)
Global trade data: UN Statistics Division, New York FAOSTAT, FAO, Rome
Volume
(billion m3/yr)
Percentage
(%)
Crops and crop products
Livestock and livestock products
Industrial products
987
276
362
61
17
22
Total 1625 100
= 16% of global water use! [Hoekstra & Chapagain, 2008]
International virtual water flows (1997-2001)
Net virtual water import (Gm3/yr)-100 - -50-50 - -25-25 - -10-10 - -5-5 - 00 - 55 - 2525 - 5050 - 100No Data
Domestic water consumption Industrial goods Agricultural goods
Water footprint per capita
Global average water footprint
[Hoekstra & Chapagain, 2008]
Global water footprintcontribution by consumption category
Global water footprint = 7450 Gm3/yr
85.8%
4.6%
9.6%
Water footprint related to consumption of industrial goods
Water footprint related to domestic water consumption
Water footprint related to consumption of agricultural goods
[Hoekstra & Chapagain, 2008]
1. Consumption characteristics
- Consumption volume
- Consumption pattern
2. Production circumstances
- Climate: evaporative demand at place of production
- Agricultural practice: water use efficiency
Major determinants of the WF
[Hoekstra & Chapagain, 2008]
The water footprint of a business
Water footprint of a retailer
bluewateruse
greywater
Farmer RetailerFood
processer
Virtualwaterflow
Virtualwaterflow
Virtualwaterflow
greenandbluewateruse
bluewateruse
greywater
greywater
Supply chain WF Operational WF
Consumer
bluewateruse
greywater
End-use WF of a product
The traditional statisticson corporate water use
[Hoekstra et al., 2011]
bluewateruse
greywater
Farmer RetailerFood
processer
Virtualwaterflow
Virtualwaterflow
Virtualwaterflow
greenandbluewateruse
bluewateruse
greywater
greywater
Supply chain WF Operational WF
Consumer
bluewateruse
greywater
End-use WF of a product
The traditional statisticson corporate water use
Water footprint of a food processor
[Hoekstra et al., 2011]
The Analysis of the Tomato Footprint, Spain
Daniel Chico, Maite Aldaya, Alberto Garrido, Gloria Salmoral and Ramon
Llamas
Chapagain, A. K. and Orr, S. (2009) “An improved water footprint methodology linking global consumption to local water resources: A case of Spanish tomatoes” Journal of Environmental Management, 90.
Chico, D., Salmoral, G., Llamas, M.R., Garrido, A. and Aldaya, M.M. (2010) "The Water Footprint and virtual water exports of Spanish Tomatoes" Papeles del Agua Virtual n.º 8, Fundación Botín, 60 p. ISBN 978-84-96655-80-05 http://www.rac.es/2/2_ficha.php?id=119&idN3=6&idN4=40
A comparison of:
Percentage variationOpen-air systems Covered systems
Significant differences by taking into account the yearly productions and not averages
Much smaller green water, as well as blue water (with exceptions)
Grey water footprint whole different results
Results Chapagain & Orr
Results Chico et al.
X 100
Approach through Temporal analysis
Increasing trend in WF associated to the increase in the tomato production
Green, Blue and Grey WF in absolute terms (hm3), national production and virtual water exported (hm3)
Advanced WF Economic analysis at current technology and market standpoint
National Water apparent productivity (WAP, €/m3) per production system
Rainfed Irrigated open-air GreenhousesShare of National production (in tons) 0.003 0.6 0.4Av. Water Apparent productivity (€/m3) 2.10 3.08 7.78
Conclusions
•The estimations on consumptive use of water for crops have usually a potential significant error
•The analysis of the economic water productivity is very important from the practical point of view
•The results obtained for the water apparent productivity vary significantly between years, although the greenhouse production shows a significantly higher productivity than irrigated open-air and rainfed production
3
SourcesHoekstra, A.Y. and Chapagain, A.K. (2008) Globalization of water: Sharing the planet's freshwater
resources, Blackwell Publishing, Oxford, UK. Hoekstra, A.Y., Chapagain, A.K., Aldaya, M.M. and Mekonnen, M.M. (2011) The water footprint
assessment manual: Setting the global standard, Earthscan, London, UK. Available from: http://www.waterfootprint.org/downloads/TheWaterFootprintAssessmentManual.pdf
Morrison, J., Morikawa, M., Murphy, M. and Schulte, P. (2009) Water scarcity and climate change: Growing risks for businesses and investors. Ceres, Pacific Institute. Available from: http://www.ceres.org/Document.Doc?id=406
WFN (2011) Water Footprint Network. Available from: http://www.waterfootprint.org