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| Titel |
A Brazilian soil hydraulic database and field capacity analysis |
| VerfasserIn |
Ana Luiza Lima Ferreira, Jos Cornelis Van Dam, Quirijn de Jong van Lier |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250101389
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| Publikation (Nr.) |
 EGU/EGU2015-517.pdf |
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| Zusammenfassung |
| Field Capacity (FC) is a widely-used concept by agricultural engineers, hydrologists and soil
physicists to quantify the available soil water during growing seasons and the accessible soil
water storage during intensive rainfall periods. In the field FC does depend on various
environmental factors, including the soil hydraulic properties, rate of evapotranspiration, root
density distribution, and groundwater level. Therefore world-wide different approaches are
used to determine field capacity, based on both static and dynamic criteria. Dynamic criteria
are usually related to the simulation of the soil internal drainage, until the percolation
attains a negligible value. Recently Assouline and Or (2014) proposed a soil intrinsic
characteristic length to determine the FC pressure head. This characteristic length is
related to the loss of hydraulic continuity and is derived from the soil water retention
function.
In Brazil soil hydraulic properties were not yet organized in a database. Therefore we
collected existing data of unsaturated soil hydraulic properties across Brazil, using
available PhD thesis and scientific publications. This inquiry resulted in a soil sample
data set of 106 horizons. We fitted the soil hydraulic parameters (θr, θs, α, n,gλ
and Ks)of the Mualem-Van Genuchten (1980) function to all soil samples. Next
we derived FC values based on soil internal drainage and using the characteristic
length according to Assouline and Or (2014). The internal drainage is analysed
with the agrohydrological model SWAP (Kroes and van Dam, 2008). In the poster
we will present the Brazilian soil hydraulic database and the derived FC values. |
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