Abstract

An assessment of the human impact on the global water cycle requires estimating the volume of water withdrawn for irrigated agriculture. A key parameter in this calculation is the irrigation efficiency, which corrects for the fraction of water lost between irrigation withdrawals and the crop due to management, distribution or conveyance losses. Here we show that the irrigation efficiency used in global irrigation models is flawed for it overlooks key ambiguities in partial efficiencies, irrigation technologies, the definition of ‘large-scale’ irrigated areas or managerial factors. Once accounted for, these uncertainties can make irrigation withdrawal estimates fluctuate by more than one order of magnitude at the country level. Such variability is larger and leads to more extreme values than that caused by the uncertainties related with climate change. Our results highlight the need to embrace deep uncertainties in irrigation efficiency to prevent the design of shortsighted policies at the river basin-water-agricultural interface.

Details

Title
Large variations in global irrigation withdrawals caused by uncertain irrigation efficiencies
Author
Puy, Arnald 1   VIAFID ORCID Logo  ; Lankford, Bruce 2 ; Meier, Jonas 3 ; van der Kooij, Saskia 4 ; Saltelli, Andrea 5 

1  Centre for the Study of the Sciences and the Humanities (SVT), University of Bergen , Parkveien 9, PB 7805, 5020 Bergen, Norway; Department of Ecology and Evolutionary Biology, Princeton University , M31 Guyot Hall, Princeton, NJ, 08544, United States of America 
2  School of International Development, University of East Anglia , Norwich NR4 7TJ, United Kingdom 
3  German Aerospace Center (DLR), German Remote Sensing Data Center (DFD) , Münchner Strasse 20, 82234 Oberpfaffenhofen, Germany 
4  Water Resources Management, Department of Environmental Sciences, Wageningen University & Research , Droevendaalsesteeg 3 6708PB Wageningen, The Netherlands 
5  Centre for the Study of the Sciences and the Humanities (SVT), University of Bergen , Parkveien 9, PB 7805, 5020 Bergen, Norway; Institute for Cognitive Sciences and Technologies of the Italian National Research Council (CNR) , Via S. Martino della Battaglia 44, 00185 Roma, Italy 
First page
044014
Publication year
2022
Publication date
Apr 2022
Publisher
IOP Publishing
e-ISSN
17489326
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1088/1748-9326/ac5768
ProQuest document ID
2640007129
Copyright
© 2022 The Author(s). Published by IOP Publishing Ltd. This work is published under http://creativecommons.org/licenses/by/4.0 (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.