Towards a second generation digital elevation model for Denmark

Abstract

Geografisk Tidsskrift, Danish Journal of Geography 99: 27–34, 1999 In 1985 the first national digital elevation model (DEM) of Denmark was produced, based on 5 m contours from topographical maps with a scale of 1:50,000. Though improved during the last decade, it is obvious that the quality of this model is not sufficient for environmental assessments related to e.g. studies of overland flows. The Danish National Survey and Cadastre, which is responsible for the mapping of the Danish topographical surface is, therefore, presently working on a new DEM derived from a product, named TOP 10DK planned for release in the year 2001. This product will feature a second generation elevation model based upon 2.5 m contours and a significant number of measured topographic elements such as streams, lakes, roads and ditches. This paper will describe the current stage of constructing digital elevation models for Denmark. DEMs will then be considered as input to environmental modelling assessments and specifications using a second generation DEM specifically requested by the Danish environmental councils. Demands concerning quality and reliability will also be discussed.