Digital Elevation Model and Digital Surface Model

Digital elevation models (DEMs) and digital surface models (DSMs) are digital representations of the Earth's surface. Almost all current geographical information systems (GIS) have some capabilities to model, present, manipulate, analyze, and visualize terrain and artificial surfaces. The rapid development of elevation data acquisition techniques has made it possible for the general public to access global and national DEM databases at various spatial scales. This advancement will greatly encourage the application of DEMs in broader fields, using analytical functions of digital terrain analysis (DTA) to derive and extract geographical, hydrological, and geomorphological parameters and features from digital elevation data.