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| Titel |
Historical development of crop-related water footprints and inter-regional virtual water flows within China |
| VerfasserIn |
La Zhuo, Mesfin M. Mekonnen, Arjen Y. Hoekstra |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250106365
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| Publikation (Nr.) |
 EGU/EGU2015-9391.pdf |
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| Zusammenfassung |
| China is facing water-related challenges, including an uneven distribution of water resources,
both temporally and spatially, and an increasing competition over the limited water resources
among different sectors. This issue has been widely researched and was finally included into
the National Plan 2011 (the 2011 No. 1 Document by the State Council of China).
However, there is still lack of information on how population growth and rapid
urbanization have affected the water resources in China over the last decades. The current
study aims at investigating (i) the intra-annual variation of green and blue water
footprints (WFs) of crop production in China over the period 1978-2009 at a spatial
resolution of 5 by 5 arc-minute; (ii) the yearly virtual water (VW) balances of 31
provinces within China, related water savings for the country, as well as the VW flows
among eight economic regions resulting from inter-regional crop trade over the same
period; and (iii) the development of the WF related to crop consumption by Chinese
consumers.
Results show that, over the period 1978-2009, the total WF related to crop production
within China increased by only 4%), but regional changes were significant. From the 1980s to
the 2000s, the shift of the cropping centre from the South to the North resulted in an increase
of about 16% in the blue WF and 19% in the green WF in the North and a reduction of the
blue and green WF in the South by 11% and 3%, respectively. China as a whole was a net
virtual water importer related to crop trade, thus saving domestic water resources. China’s
inter-regional crop trade generated a blue water ‘loss’ annually by transferring crops from
provinces with relatively low crop water productivity to provinces with relatively
high productivity. Over the decades, the original VW flow from the South coastal
region to the Northeast was reversed. Rice was the all-time dominant crop in the
inter-regional VW flows (accounting for 34% in 2009), followed by wheat and maize. The
WF of the South related to crop consumption increased by 17% (~61 billion m3)
while the increase in the North was 8% (~23 billion m3) from the 1980s to the
2000s. The national average annual WF per capita of crop consumption reduced by
8% (from 606 m3cap-1y-1 to 559 m3cap-1y-1) from the 1980s to the 2000s
owing to the reduction in the WF per unit mass of a crop. However, because of the
movement of the major agricultural areas to the North, the WF per capita in Inner
Mongolia, for example, was increased (by 4% from the 1980s to the 2000s) due
to the higher WF per unit mass of a crop locally, but with an increased level of
self-reliance in crop consumption. Accounting for the different production and
consumption characteristics across provinces is crucial for China’s water governance. |
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