Publication Date:
2022-05-25
Description:
Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Global Change Biology 17 (2011): 1821–1833, doi:10.1111/j.1365-2486.2011.02392.x.
Description:
Large-scale soy agriculture in the southern Brazilian Amazon now rivals
deforestation for pasture as the region’s predominant form of land use change. Such
landscape level change can have substantial consequences for local and regional
hydrology, which remain relatively unstudied. We examined how the conversion to soy
agriculture influences water balances and stormflows using stream discharge (water
yields) and the timing of discharge (stream hydrographs) in small (2.5 to 13.5 km2)
forested and soy headwater watersheds in the Upper Xingu Watershed in the state of
Mato Grosso, Brazil. We monitored water yield for one year in three forested and four
soy watersheds. Mean daily water yields were approximately four times higher in soy
than forested watersheds, and soy watersheds showed greater seasonal variability in
discharge. The contribution of stormflows to annual streamflow in all streams was low (〈
13% of annual streamflow), and the contribution of stormflow to streamflow did not
differ between land uses. If the increases in water yield observed in this study are typical,
landscape-scale conversion to soy substantially alters water-balance, potentially altering
the regional hydrology over large areas of the southern Amazon.
Description:
This project
was supported by grants from NSF (DEB-0640661) and the Fundaçao de Amparo à
Pesquisa do Estado de São Paulo (FAPESP 03/13172-2).
Keywords:
Hydrology
;
Water yield
;
Baseflow
;
Land use change
;
Amazon
;
Soybean cultivation
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
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