Modelling interception loss from evergreen oak Mediterranean savannas: Application of a tree-based modelling approach

• Published in: Agricultural and forest meteorology Vol. 149; no. 3; pp. 680 - 688
• Main Authors: Pereira, F.L., Gash, J.H.C., David, J.S., David, T.S., Monteiro, P.R., Valente, F.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 11.03.2009; [Oxford]: Elsevier Science Ltd; Elsevier
• Subjects: Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agronomy. Soil science and plant productions; Biological and medical sciences; ecosystem evaporation; equations; estimation; evaporation; forest ecosystems; forest trees; Fundamental and applied biological sciences. Psychology; Gash analytical model; General agronomy. Plant production; Isolated trees; model validation; Quercus ilex; rain; rain interception; Rainfall interception; Savannas; tree crown; vegetation cover; water vapor; Wet bulb temperature; woodlands; Portugal; ANE, Portugal; MED; Quercus ilex; Isolated trees; Rainfall interception; Gash analytical model; Savannas; Wet bulb temperature; Biometeorology; Temperature; Methodology; Physical environment; Modeling; Evergreen plant; Rain; Dicotyledones; Angiospermae; Hardwood forest tree; Interception; Vegetals; Meteorological phenomenon; Savannah; Forest tree; Woody plant; Fagaceae; Analytical model; Vegetation type; Bulb; Vegetation; Analytical method; Approach; Spermatophyta; Atmospheric precipitation; Mediterranean region; Application
• ISSN: 0168-1923; 1873-2240
• DOI: 10.1016/j.agrformet.2008.10.014

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 from savanna-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 savanna-type ecosystems.