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| Titel |
The water balance components of undisturbed tropical woodlands in the Brazilian cerrado |
| VerfasserIn |
P. T. S. Oliveira, E. Wendland, M. A. Nearing, R. L. Scott, R. Rosolem, H. R. da Rocha |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 19, no. 6 ; Nr. 19, no. 6 (2015-06-22), S.2899-2910 |
| Datensatznummer |
250120749
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| Publikation (Nr.) |
 copernicus.org/hess-19-2899-2015.pdf |
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| Zusammenfassung |
| Deforestation of the Brazilian cerrado region has caused
major changes in hydrological processes. These changes in water balance
components are still poorly understood but are important for making land
management decisions in this region. To better understand pre-deforestation
conditions, we determined the main components of the water balance for an
undisturbed tropical woodland classified as "cerrado sensu stricto denso".
We developed an empirical model to estimate actual evapotranspiration (ET)
by using flux tower measurements and vegetation conditions inferred from
the enhanced vegetation index and reference evapotranspiration. Canopy
interception, throughfall, stemflow, surface runoff, and water table level
were assessed from ground measurements. We used data from two cerrado sites,
Pé de Gigante (PDG) and Instituto Arruda Botelho (IAB). Flux tower
data from the PDG site collected from 2001 to 2003 were used to develop
the empirical model to estimate ET. The other hydrological processes were
measured at the field scale between 2011 and 2014 at the IAB site. The
empirical model showed significant agreement (R2 = 0.73) with observed
ET at the daily timescale. The average values of estimated ET at the IAB
site ranged from 1.91 to 2.60 mm day−1 for the dry and wet seasons,
respectively. Canopy interception ranged from 4 to 20 % and stemflow
values were approximately 1 % of the gross precipitation. The average runoff
coefficient was less than 1 %, while cerrado deforestation has the
potential to increase that amount up to 20-fold. As relatively little excess
water runs off (either by surface water or groundwater), the water storage
may be estimated by the difference between precipitation and
evapotranspiration. Our results provide benchmark values of water balance
dynamics in the undisturbed cerrado that will be useful to evaluate past and
future land-cover and land-use changes for this region. |
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