Green and blue water demand from large-scale land acquisitions in Africa
Johansson, Emma Li LU ; Fader, Marianela ; Seaquist, Jonathan W. LU and Nicholas, Kimberly A. LU
(2016)
In Proceedings of the National Academy of Sciences of the United States of America
113(41).
p.11471-11476
- Abstract
In the last decade, more than 22 million ha of land have been contracted to large-scale land acquisitions in Africa, leading to increased pressures, competition, and conflicts over freshwater resources. Currently, 3% of contracted land is in production, for which we model site-specific water demands to indicate where freshwater appropriation might pose high socioenvironmental challenges. We use the dynamic global vegetation model Lund-Potsdam-Jena managed Land to simulate green (precipitation stored in soils and consumed by plants through evapotranspiration) and blue (extracted from rivers, lakes, aquifers, and dams) water demand and crop yields for seven irrigation scenarios, and compare these data with two baseline scenarios of staple... (More)
In the last decade, more than 22 million ha of land have been contracted to large-scale land acquisitions in Africa, leading to increased pressures, competition, and conflicts over freshwater resources. Currently, 3% of contracted land is in production, for which we model site-specific water demands to indicate where freshwater appropriation might pose high socioenvironmental challenges. We use the dynamic global vegetation model Lund-Potsdam-Jena managed Land to simulate green (precipitation stored in soils and consumed by plants through evapotranspiration) and blue (extracted from rivers, lakes, aquifers, and dams) water demand and crop yields for seven irrigation scenarios, and compare these data with two baseline scenarios of staple crops representing previous water demand. We find that most land acquisitions are planted with crops that demand large volumes of water (>9,000 m3·ha-1) like sugarcane, jatropha, and eucalyptus, and that staple crops have lower water requirements (<7,000 m3·ha-1). Blue water demand varies with irrigation system, crop choice, and climate. Even if the most efficient irrigation systems were implemented, 18% of the land acquisitions, totaling 91,000 ha, would still require more than 50% of water from blue water sources. These hotspots indicate areas at risk for transgressing regional constraints for freshwater use as a result of overconsumption of blue water, where socioenvironmental systems might face increased conflicts and tensions over water resources.
(Less)
- author
- Johansson, Emma Li
LU
; Fader, Marianela
; Seaquist, Jonathan W.
LU
and Nicholas, Kimberly A.
LU
- organization
- publishing date
- 2016-10-11
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Irrigation, Land grabbing, Lpjml, Water footprints, Water scarcity
- in
- Proceedings of the National Academy of Sciences of the United States of America
- volume
- 113
- issue
- 41
- pages
- 6 pages
- publisher
- National Academy of Sciences
- external identifiers
-
- scopus:84991453536
- pmid:27671634
- wos:000384886900057
- ISSN
- 0027-8424
- DOI
- 10.1073/pnas.1524741113
- language
- English
- LU publication?
- yes
- id
- 9167031f-883f-4d2a-8d1c-aae7cdbd3da5
- date added to LUP
- 2016-10-31 12:18:49
- date last changed
- 2024-05-03 12:35:43
@article{9167031f-883f-4d2a-8d1c-aae7cdbd3da5,
abstract = {{<p>In the last decade, more than 22 million ha of land have been contracted to large-scale land acquisitions in Africa, leading to increased pressures, competition, and conflicts over freshwater resources. Currently, 3% of contracted land is in production, for which we model site-specific water demands to indicate where freshwater appropriation might pose high socioenvironmental challenges. We use the dynamic global vegetation model Lund-Potsdam-Jena managed Land to simulate green (precipitation stored in soils and consumed by plants through evapotranspiration) and blue (extracted from rivers, lakes, aquifers, and dams) water demand and crop yields for seven irrigation scenarios, and compare these data with two baseline scenarios of staple crops representing previous water demand. We find that most land acquisitions are planted with crops that demand large volumes of water (>9,000 m<sup>3</sup>·ha<sup>-1</sup>) like sugarcane, jatropha, and eucalyptus, and that staple crops have lower water requirements (<7,000 m<sup>3</sup>·ha<sup>-1</sup>). Blue water demand varies with irrigation system, crop choice, and climate. Even if the most efficient irrigation systems were implemented, 18% of the land acquisitions, totaling 91,000 ha, would still require more than 50% of water from blue water sources. These hotspots indicate areas at risk for transgressing regional constraints for freshwater use as a result of overconsumption of blue water, where socioenvironmental systems might face increased conflicts and tensions over water resources.</p>}},
author = {{Johansson, Emma Li and Fader, Marianela and Seaquist, Jonathan W. and Nicholas, Kimberly A.}},
issn = {{0027-8424}},
keywords = {{Irrigation; Land grabbing; Lpjml; Water footprints; Water scarcity}},
language = {{eng}},
month = {{10}},
number = {{41}},
pages = {{11471--11476}},
publisher = {{National Academy of Sciences}},
series = {{Proceedings of the National Academy of Sciences of the United States of America}},
title = {{Green and blue water demand from large-scale land acquisitions in Africa}},
url = {{http://dx.doi.org/10.1073/pnas.1524741113}},
doi = {{10.1073/pnas.1524741113}},
volume = {{113}},
year = {{2016}},
}