Abstract

This study examined the spatial variability of rainfall across a network of 46 raingauges within a 4 km² rainforest catchment within the interior of northeastern Borneo. Correlation of seasonal rainfall totals with raingauge separation distance, aspect and relief was undertaken.

The analyses indicated a very high degree of spatial variability in seasonal totals across a very small area, even in comparison with other regions experiencing convective rainfall. Moreover, it is the first work in the humid tropics to show that systematic, stochastic structure is present within rainfall over scales of 10's to 100's metres, and that these patterns change from the Southwest monsoon (May-October) to the Northeast monsoon (November-April). Local associations with aspect and relief are present, but explanation of the seasonal changes in rainfall pattern over the whole 4 km² catchment must relate to more complex local topographic effects on the regional windfield.