National DEM represents the Earth’s surface forms as a regular mesh of height points and it is part of the national basic spatial data sets. DEMs can be used, for example, in spatial analyses related to flood control, flood protection, and dam safety. In addition, the DEMs have been used in surface water flow applications, such as investigations related to leaching of soil nutrition and soil erosion. Until nowadays, the national DEM is primarily based on the topographic contours, but in the future the DEM will be the primary spatial data set representing the landscape’s topography.
The research focuses on the possibilities to measure, characterise and model the DEM errors. In addition, the research tries to resolve how the quality metadata should be taken into account in DEM-based spatial analyses and proposals for the appropriate use of the national DEM will be prepared. For the future needs of topographical mapping, the usability of DEMs in automatic medium-scale topographic contour production will be investigated.