Higher resolution upslope catchment area values at finer grid sizes are lost, and slopes are underestimated, when DEMs with a coarse grid resolution are used. Thus dominating geomorphological parameters are directly influenced by the scale of DEM resolution. To overcome this problem, downscaling methods have been derived for both upslope catchment area and slope by introducing the concepts of number of sub-grids, influence factor and fractal method for scaled steepest slope. An application of the disaggregation method has been shown in the Kamishiiba catchment (210 km(2)) in Japan, with the successful derivation of the target fine resolutions for upslope catchment area and slope information from 1000 in DEM resolution.