Global-scale analysis of river flow alterations due to water withdrawals and reservoirs

  • Global-scale information on natural river flows and anthropogenic river flow alterations is required to identify areas where aqueous ecosystems are expected to be strongly degraded. Such information can support the identification of environmental flow guidelines and a sustainable water management that balances the water demands of humans and ecosystems. This study presents the first global assessment of the anthropogenic alteration of river flow regimes by water withdrawals and dams, focusing in particular on the change of flow variability. Six ecologically relevant flow indicators were quantified using an improved version of the global water model WaterGAP. WaterGAP simulated, with a spatial resolution of 0.5 degree, river discharge as affected by human water withdrawals and dams, as well as naturalized discharge without this type of human interference. Mainly due to irrigation, long-term average river discharge and statistical low flow Q90 (monthly river discharge that is exceeded in 9 out of 10 months) have decreased by more than 10% on one sixth and one quarter of the global land area (excluding Antarctica and Greenland), respectively. Q90 has increased significantly on only 5% of the land area, downstream of reservoirs. Due to both water withdrawals and dams, seasonal flow amplitude has decreased significantly on one sixth of the land area, while interannual variability has increased on one quarter of the land area mainly due to irrigation. It has decreased on only 8% of the land area, in areas with little consumptive water use that are downstream of dams. Areas most affected by anthropogenic river flow alterations are the western and central USA, Mexico, the western coast of South America, the Mediterranean rim, Southern Africa, the semi-arid and arid countries of the Near East and Western Asia, Pakistan and India, Northern China and the Australian Murray-Darling Basin, as well as some Arctic rivers. Due to a large number of uncertainties related e.g. to the estimation of water use and reservoir operation rules, the analysis is expected to provide only first estimates of river flow alterations that should be refined in the future.

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Metadaten
Author:Petra DöllORCiDGND, Kristina Fiedler, Jing Zhang
URN:urn:nbn:de:hebis:30:3-292116
DOI:https://doi.org/10.5194/hessd-6-4773-2009
ISSN:1812-2116
ISSN:1812-2108
Parent Title (English):Hydrology and earth system sciences discussions. 6.2009, S. 4773-4812
Publisher:European Geophysical Society
Place of publication:Katlenburg-Lindau
Document Type:Article
Language:English
Date of Publication (online):2009/07/03
Date of first Publication:2009/07/03
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2013/03/19
Volume:6
Page Number:40
First Page:4773
Last Page:4812
Note:
© Author(s) 2009. This work is distributed under the Creative Commons Attribution 3.0 License.
HeBIS-PPN:221540296
Institutes:Geowissenschaften / Geographie / Geowissenschaften
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften
Sammlungen:Universitätspublikationen
Licence (German):License LogoCreative Commons - Namensnennung 3.0