Interception loss as a function of rainfall and forest types: stochastic modelling for tropical canopies revisited

The dependence of interception loss from different tropical tree canopies on rainfall type was investigated using a two-layer stochastic model that simulates all stages in the process of rainfall interception. The effect of different types of rainfall (drizzle, thunderstorm and widespread rain), was investigated using three power laws relating raindrop sizes to rainfall intensity. The study showed the importance of canopy characteristics in determining the stochastic wetting processes that explain the differences in interception loss between species. It also showed that predicted interception loss is relatively insensitive to raindrop size and also, therefore, to the choice of relationship between rainfall intensity and raindrop sizes used in the model. Any significant changes in interception loss resulting from climate change effects will therefore not be from changes in rainfall intensity (which affects drop size), but from any changes in storm sizes and frequency.