Assessment of potential implications of agricultural irrigation policy on surface water scarcity in Brazil
Expanding irrigated cropping areas is one of Brazil's strategies to increase agricultural production. This expansion is constrained by water policy goals to restrict water scarcity to acceptable levels. We therefore analysed the trade-off between levels of acceptable water scarcity and feasible...
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Published in: | Hydrology and earth system sciences Vol. 24; no. 1; pp. 307 - 324 |
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Main Authors: | , , , , , , |
Format: | Journal Article |
Language: | English |
Published: |
Katlenburg-Lindau
Copernicus GmbH
21-01-2020
Copernicus Publications |
Subjects: | |
Online Access: | Get full text |
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Summary: | Expanding irrigated cropping areas is one of Brazil's
strategies to increase agricultural production. This expansion is
constrained by water policy goals to restrict water scarcity to acceptable
levels. We therefore analysed the trade-off between levels of acceptable
water scarcity and feasible expansion of irrigation. The appropriateness of
water use in agricultural production was assessed in categories ranging from
acceptable to very critical based on the river flow that is equalled or
exceeded 95 % of the time (Q95) as an indicator for physical water
availability. The crop water balance components were determined for 166 842 sub-catchments covering all of Brazil. The crops considered were cotton,
rice, sugarcane, bean, cassava, corn, soybean and wheat, together accounting
for 96 % of the harvested area of irrigated and rain-fed agriculture. On
currently irrigated land irrigation must be discontinued on 54 % (2.3 Mha)
for an acceptable water scarcity level, on 45 % (1.9 Mha) for a
comfortable water scarcity level and on 35 % (1.5 Mha) for a worrying
water scarcity level, in order to avoid critical water scarcity. An
expansion of irrigated areas by irrigating all 45.6 Mha of the rain-fed area
would strongly impact surface water resources, resulting in 26.0 Mha
experiencing critical and very critical water scarcity. The results show in
a spatially differentiated manner that potential future decisions regarding
expanding irrigated cropping areas in Brazil must, while pursuing to
intensify production practices, consider the likely regional effects on
water scarcity levels, in order to reach sustainable agricultural
production. |
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ISSN: | 1607-7938 1027-5606 1607-7938 |
DOI: | 10.5194/hess-24-307-2020 |