Establishing and testing a catchment water footprint framework to inform sustainable irrigation water use for an aquifer under stress.

Autor: le Roux B; Department of Plant and Soil Sciences, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa. Electronic address: betsielr@gmail.com., van der Laan M; Department of Plant and Soil Sciences, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa. Electronic address: Michael.vanderLaan@up.ac.za., Vahrmeijer T; Department of Plant and Soil Sciences, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa; Citrus Research International, PO Box 28, Nelspruit 1200, South Africa. Electronic address: Teunis.Vahrmeijer@up.ac.za., Bristow KL; Department of Plant and Soil Sciences, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa; CSIRO Agriculture, PMB Aitkenvale, Townsville, QLD 4814, Australia. Electronic address: Keith.Bristow@csiro.au., Annandale JG; Department of Plant and Soil Sciences, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa. Electronic address: John.Annandale@up.ac.za.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2017 Dec 01; Vol. 599-600, pp. 1119-1129. Date of Electronic Publication: 2017 May 12.
DOI: 10.1016/j.scitotenv.2017.04.170
Abstrakt: Future water scarcities in the face of an increasing population, climate change and the unsustainable use of aquifers will present major challenges to global food production. The ability of water footprints (WFs) to inform water resource management at catchment-scale was investigated on the Steenkoppies Aquifer, South Africa. Yields based on cropping areas were multiplied with season-specific WFs for each crop to determine blue and green water consumption by agriculture. Precipitation and evapotranspiration of natural vegetation and other uses of blue water were included with the agricultural WFs to compare water availability and consumption in a catchment sustainability assessment. This information was used to derive a water balance and develop a catchment WF framework that gave important insights into the hydrology of the aquifer through a simplified method. This method, which requires the monitoring of only a few key variables, including rainfall, agricultural production, WFs of natural vegetation and other blue water flows, can be applied to inform the sustainability of catchment scale water use (as opposed to more complex hydrological studies). Results indicate that current irrigation on the Steenkoppies Aquifer is unsustainable. This is confirmed by declining groundwater levels, and suggests that there should be no further expansion of irrigated agriculture on the Steenkoppies Aquifer. Discrepancies between in- and outflows of water in the catchment indicated that further development of the WF approach is required to improve understanding of the geohydrology of the aquifer and to set and meet sustainability targets for the aquifer. It is envisaged that this 'working' framework can be applied to other water-stressed aquifers around the world.
(Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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