A COMPARISON OF MODELS SIMULATING RAINFALL INTERCEPTION OF FORESTS

Rainfall interception models have been validated using observations from a coniferous forest in France and a deciduous forest in the Netherlands. The models differ in level of complexity. This complexity, however, appears to have only a secondary effect on the results. The most sensitive factor in the models is shown to be the evaporation rate of the intercepted water. The evaporation rate is determined from the atmospheric vapour pressure deficit and the aerodynamic resistance using the Penman equation. In the models, the aerodynamic resistance is approximated from momentum transport. This approximation leads to an overestimation of interception. The models can be improved by using a simple and well-known correction for the aerodynamic resistance.