Automated extraction of geomorphometric properties from digital elevation data

The rapidly increasing availability of gridded, digital elevation data has promoted the development of sophisticated computer algorithms for the calculation of geomorphometric properties of the land surface. These algorithms facilitate the computation of parameters that are tedious to do by hand, for example, hypsometric curves or the tabulation of stream properties by order for large drainage basins. Secondly, these algorithms can be used to calculate geomorphometric properties that have not been generally amenable to calculation, for example, frequency distribution plots of slope and aspect for entire drainage basins or the complete flow path from drainage divide to basin outlet for any and every location within the drainage basin. Thirdly, these algorithms generate large, areally extensive data sets, that with appropriate statistical analyses can be used to explore spatial trends, for example, hillslope or stream network properties as a function of rock type, climate, or neotectonic environment. We describe the basic algorithm structure for computing geomorphometric properties and give a set of representative examples of different parameters for a basin in the physiographic province known as the Appalachian Plateau, in Pennsylvania, USA. -from Authors