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| Titel |
Irrigation efficiency and water-policy implications for river basin resilience |
| VerfasserIn |
C. A. Scott, S. Vicuña, I. Blanco-Gutiérrez, F. Meza, C. Varela-Ortega |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 18, no. 4 ; Nr. 18, no. 4 (2014-04-07), S.1339-1348 |
| Datensatznummer |
250120326
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| Publikation (Nr.) |
 copernicus.org/hess-18-1339-2014.pdf |
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| Zusammenfassung |
| Rising demand for food, fiber, and biofuels drives
expanding irrigation withdrawals from surface water and groundwater. Irrigation
efficiency and water savings have become watchwords in response to
climate-induced hydrological variability, increasing freshwater demand for
other uses including ecosystem water needs, and low economic productivity of
irrigation compared to most other uses. We identify three classes of
unintended consequences, presented here as paradoxes. Ever-tighter cycling
of water has been shown to increase resource use, an example of the
efficiency paradox. In the absence of effective policy to
constrain irrigated-area expansion using "saved water", efficiency can
aggravate scarcity, deteriorate resource quality, and impair river basin
resilience through loss of flexibility and redundancy. Water scarcity and
salinity effects in the lower reaches of basins (symptomatic of the
scale paradox) may partly be offset over the short-term through
groundwater pumping or increasing surface water storage capacity. However,
declining ecological flows and increasing salinity have important
implications for riparian and estuarine ecosystems and for non-irrigation
human uses of water including urban supply and energy generation, examples
of the sectoral paradox. This paper briefly considers three
regional contexts with broadly similar climatic and water-resource
conditions – central Chile, southwestern US, and south-central
Spain – where irrigation efficiency directly influences basin resilience.
The comparison leads to more generic insights on water policy in relation to
irrigation efficiency and emerging or overdue needs for environmental protection. |
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