Since the advent of the first Landsat series of Earth resources satellites, many researchers have successfully mapped land cover types, especially in areas of low relief. However, in areas of rugged terrain these are complicated and only limited success has been reported. In this paper topographic effects have been analysed using a radiance model. The model was used to separate the illumination effect from the underlying land cover reflectance. The main thrust of the approach presented here is that, without using a digital terrain model, it is possible to separate the shading and spectral effect in the two indexing classifications by using the log transformations and band ratios applied to Landsat Multispectral Scanner data. The Landsat data were classified in terms of different land cover types found in the northeastern mountainous region of Tasmania, Australia.