A DESCRIPTION OF RAINFALL INTERCEPTION OVER LARGE AREAS

A new scheme is developed for describing interception at spatial scale s comparable to the typical resolution of climate models. The scheme i s based on the Rutter model of interception and statistical descriptio n of the subgrid-scale spatial variability of canopy storage and rainf all. The interception loss simulated by the new scheme is significantl y smaller than those simulated by other schemes that do not include co nsiderations for spatial variability. The explanation of this result i s partly in the enhancement of spatially averaged canopy drainage due to the large local drainage from the few buckets of large canopy stora ge. The relative reduction in interception loss simulated by the new s cheme may explain the overestimation of interception loss by climate m odels that do not include the effects of spatial variability on interc eption processes.