Green water strategic importance in international crop trade

Transcription

1 Fourth International Workshop on Hydro-Hegemony Hegemony London, 31 May 1 June 2008 Green water strategic importance in international crop trade Maite M. Aldaya maite_m_aldaya@geo.ucm.es Complutense University of Madrid

2 Table of contents 1. Introduction 2. Green water strategic importance 3. Water Footprint of Spain References

3 Table of contents 1. Introduction 2. Green water strategic importance 3. Water Footprint of Spain References

4 1. Introduction: Concepts Virtual water is the volume of water (green and/or blue) used to produce a good or service (Allan, 1993, 2003). Evapotranspiration Green water Blue water Blue water

5 1. Introduction: Virtual water trade Virtual water trade If one kilo of grain (1 m 3 ) is imported to a water short region, then that economy saves the economic and political stress of mobilising about 1 m 3 of water. reducing the demand on local (green and blue) water resources that can be used to provide: 1. Ecological services 2. Other more lucrative uses

6 1. Introduction 2. Green water strategic importance 3. Water Footprint of Spain References

7 2. Strategic importance of Green Water in international crop trade Green and blue water proportion in the virtual-water embedded in the maize, soybean and wheat exports of main exporting countries (km 3 /year). The size of the pie is determined by the exported amount of virtual water. Period Maize USA Argentina Canada Argentina 0.24 Soybeans Canada USA Wheat USA Argentina 0.22 Canada Australia

8 2. Strategic importance of Green Water in international crop trade: USA The corn belt Midwest of the USA, primarily including Iowa, Indiana, Illinois, y Ohio Green and blue water resource use for the USA maize production by state (m 3 /ton). The size of each pie reflects the state contribution to the national production.

9 2. Strategic importance of Green Water in international crop trade: USA Groundwater withdrawal in the Midwest USA, e.g. Ogallala Aquifer (450,000 km²). Most productive regions for growing maize, soybean and wheat breadbasket of America, no adequate precipitation. Extracting rates > natural replacement rate Green and blue water resource use for the USA winter wheat production by state (m 3 /ton). The size of each pie reflects the state contribution to the national production.

10 2. Strategic importance of Green Water in international crop trade Today water crisis, and most hydrological conflicts, are not caused by physical scarcity of water. They are mainly due to poor water management.

11 2. Strategic importance of Green Water in international crop trade CONCLUSIONS Virtual water trade is useful to improve food and water security in water scarce countries. But determined by: technology increases in the productivity of soil water and irrigation water level of socio-economic development national food policies international trade agreements

12 1. Introduction 2. Green water strategic importance 3. Water Footprint of Spain References

13 3. Water Footprint of Spain Economic value produced by irrigated agriculture in Spain. Data for 78% of the irrigated area. M /m 3 3 /m 3 1 /m 3 0,6 /m ,4 /m 3 0,2 /m 3 0,02 /m Blue water use (Mm 3 /year) Source: based on data from the Spanish Ministry for the Environment (2007)

14 3. Water Footprint of Spain Water apparent productivity (Gross Value Added per cubic metre GVA/m 3 ) per crop type in irrigated agriculture in Spain for the year Data for 78% of the irrigated area. 7,00 6,00 5,00 GVA ( /m 3 ) 4,00 3,00 2,00 1,00 0,00 Cereals Rice and Maize Other crops Olive tree Citrus trees Other fruit trees Vineyard Vegetables Greenhouse crops Source: based on data from the Spanish Ministry for the Environment (2007)

15 3. Water Footprint of Spain More crops and jobs per drop More cash and nature per drop

16 1. Introduction 2. Green water strategic importance 3. Water Footprint of Spain References

17 References Aldaya, M.M., Hoekstra, A.Y. and Allan, J.A. (2008) Strategic importance of green water in international crop trade. Value of Water Report Series, UNESCO-IHE. Delft, The Netherlands. Allan, J.A. (2003) "Virtual Water- the water, food, and trade nexus useful concept or misleading metaphor?" Water International 28 (1): Allan, J.A. (2006) Virtual Water, Part of an invisible synergy that ameliorates water scarcity. In Water Crisis: Myth or Reality? Ed. Rogers, Llamas and Martinez-Cortina. Balkema Publishers. Chapagain, A.K. and Hoekstra, A.Y. (2004) Water Footprints of Nations. Value of Water Research Report Series No. 16, UNESCO- IHE. Delft, The Netherlands. Hoekstra, A.Y. and Hung, P.Q. (2002) Virtual water trade: a quantification of virtual waterflows between nations in relation to international crop trade. Value of Water Research Report Series No. 11. UNESCO-IHE. Delft, The Netherlands.

18 THANK YOU