Brussels-Capital Region : The Digital Terrain Model (DTM) describes the three-dimensional shape of the surface of the Earth (topography of the surface). The Digital Terrain Model (DTM) is available in three different representations: - Elevation - vector elements; - Elevation - Grid; - Elevation - TIN.

Brussels-Capital Region: Contour lines give an overview of the real ground on a topographic map. A contour line is the intersection of real terrain with a horizontal plane of given elevation. Contour lines are obtained from the Digital Terrain Model (DTM).