Modelling interception loss from evergreen oak Mediterranean savannas: applicat...

• Author(s): Pereira, F.L. ; Gash, J.H.C. ; David, J.S. ; David, T.S. ; Monteiro, P.R. ; Valente, F.
• Date: 2009
• Persistent ID: http://hdl.handle.net/10400.5/5931
• Origin: Repositório da UTL
• Subject(s): rainfall interception; isolated trees; savannas; Quercus ilex; wet bulb temperature; Gash analytical model
• Document Type: Article
• Language: English

Description

In a previous study, it was shown that an isolated, fully saturated tree-crown behaves like a wet bulb, allowing evaporation of intercepted rainfall to be estimated by a simple diffusion equation for water vapour. This observation was taken as the basis for a new approach in modelling interception loss fromsavanna-type woodland, whereby the ecosystem evaporation is derived by scaling up the evaporation from individual trees, rather than by considering a homogeneous forest cover. Interception loss from isolated trees was estimated by combining the aforementioned equation for water vapour flux with Gash’s analytical model. A new methodology, which avoids the subjectivity inherent in the Leyton method, was used for estimating the crown storage capacity. Modelling performance was evaluated against data from two Mediterranean savanna-type oak woodlands (montados) in southern Portugal. Interception loss estimates were in good agreement with observations in both sites. The proposed modelling approach is physically based, requires only a limited amount of data and should be suitable for the modelling of interception loss in isolated trees and savannatype ecosystems