Assessing water security in the São Paulo metropolitan region under projected climate change
<p>Climate change affects the global water cycle and has the potential to alter water availability for food–energy–water production, and for ecosystems services, on regional and local scales. An understanding of these effects is crucial for assessing future water availability, and for the deve...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-12-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | https://www.hydrol-earth-syst-sci.net/23/4955/2019/hess-23-4955-2019.pdf |
| Summary: | <p>Climate change affects the global water cycle and has the potential to alter
water availability for food–energy–water production, and for ecosystems
services, on regional and local scales. An understanding of these effects is
crucial for assessing future water availability, and for the development of
sustainable management plans. Here, we investigate the influence of
anticipated climate change on water security in the Jaguari Basin, which is
the main source of freshwater for 9 million people in the São Paulo
metropolitan region (SPMR). First, we calibrate and evaluate a hydrological
model using daily observed data, obtaining satisfactory coefficient of
determination and Kling–Gupta efficiency values for both periods. To
represent possible climate change scenarios up to 2095, we consider two
International Panel on Climate Change (IPCC) Representative Concentration
Pathways (RCP4.5 and RCP8.5) and use an ensemble of future projections
generated by 17 general circulation models (GCMs). These data were used to
drive the hydrological model to generate projected scenarios of streamflow.
We then used indicators of water scarcity and vulnerability to carry out a
quantitative analysis of provision probability. Our results indicate that
streamflow can be expected to exhibit increased interannual variability,
significant increases in flow rate between January and March, and a
2-month extension of the hydrological dry season (currently June to
September) until November. The latter includes a more than a 35 % reduction
in streamflow during September through November (with a > 50 %
reduction in October). Our findings indicate an increased risk of floods and
droughts accompanied by an expansion of the basin critical period, and our
analysis of the water security indices identifies October and November as
the most vulnerable months. Overall, our analysis exposes the fragility of
water security in the São Paulo metropolitan region, and provides valuable
technical and scientific information that can be used to guide regional
plans and strategies to cope with potential future water scarcity.</p> |
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| ISSN: | 1027-5606 1607-7938 |