Evaporation and storage of intercepted rain analysed by comparing two models applied to a boreal forest

Rainfall and throughfall were measured during the summer of 1995. Rainfall interception is often simulated by a version of the well-known Rutter-Gash analytical model. In this study this model was compared to a model based on an exponential saturation equation. The concept of the 'minimum method' for deriving canopy storage capacity and free throughfall coefficient by the Leyton-analysis, is compared to the concept of maximum storage capacity by reversing the models. Measured evaporation rate during rain events was found to be lower than simulated by the Penman equation using different known formulations for aerodynamic resistance. The concept of a high internal canopy resistance and decoupling of the canopy from the atmosphere should be analysed further in order to explain low evaporation during rainfall. (C) 1999 Elsevier Science B.V. All rights reserved.