ABSTRACT
Digital elevation models (DEMs) are often used within a GIS environment to characterise elements of the real surface they represent. Characterisations may be of relatively low-level properties, here referred to as morphometric parameters, such as slope magnitude, slope direction, surface convexity. This chapter discusses methods of morphometric characterisation that involve a multi-scale description of surface form. It presents a method of multi-scale characterisation. Multi-scale quadratic approximation is shown to have use in generalisation of elevation models, and in the derivation of meaningful morphometric parameters and features. Geomorphological characterisation of landscape involves the appreciation of surface form at a number of scales. Smoothing is useful for the basis of re-sampling at different scales, for the calculation of more realistic shaded relief, and as the basis of terrain visualisation. Characterisation of landscape properties through the measurement of morphometric parameters is a necessary part of many DEM based applications ranging from hydrological characterisation to landslide risk assessment.
