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Kimberly Nicholas

Kimberly Nicholas

Senior Lecturer, Docent, Director of Studies PhD school

Kimberly Nicholas

Green and blue water demand from large-scale land acquisitions in Africa

Author

  • Emma Li Johansson
  • Marianela Fader
  • Jonathan W. Seaquist
  • Kimberly A. Nicholas

Summary, in English

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.

Department/s

  • Dept of Physical Geography and Ecosystem Science
  • LUCSUS (Lund University Centre for Sustainability Studies)
  • BECC - Biodiversity and Ecosystem services in a Changing Climate

Publishing year

2016-10-11

Language

English

Pages

11471-11476

Publication/Series

Proceedings of the National Academy of Sciences of the United States of America

Volume

113

Issue

41

Document type

Journal article

Publisher

National Acad Sciences

Topic

  • Environmental Sciences related to Agriculture and Land-use

Keywords

  • Irrigation
  • Land grabbing
  • Lpjml
  • Water footprints
  • Water scarcity

Status

Published

ISBN/ISSN/Other

  • ISSN: 0027-8424