Rainfall interception from a lowland tropical rainforest in Brunei

Results from a programme of throughfall measurements in a lowland tropical rainforest in Brunei, northwest Borneo, indicate that interception losses amount to 18% of the gross incident rainfall. The high annual rainfall experienced bq the study area results in annual interception losses of around 800 mm, which may result in total annual evapotranspiration losses significantly higher than in other rainforest locations. An improved version of Cash's analyticaI interception model is tested on the available data using assumed values for the "forest" parameters, and is found to predict interception losses extremely well, The model predictions are based on an estimated evaporation rate during rainfall of 0.71 mm h(-1). This is significantly higher than has been reported in other tropical studies. It is concluded that these results are distinctive when compared with previous results from rainforests, and that further, detailed work is required to establish whether the enhanced evaporation rate is due to advective effects associated with the maritime setting of the study area. (C) 1997 Elsevier Science B.V.