Digital Basic Landscape Model (Base DLM)

The landscape is described by object-structured vector data and stored permanently in a database. The objects, e.g. lined landscape structures such as traffic routes or area-like landscape areas such as settlement areas, vegetation and water areas, are defined according to their shape and location by coordinates in the national system and described in their properties by attributes (e.g. road classification, type of vegetation). The landscape models are continued on a regular basis every 4 years and with regard to selected object types (e.g. roads) (peak up-to-date). The content of the basic DLM is defined in an object type catalog. In Lower Saxony, the basic DLM currently comprises around 130 object types. With the third and final stage of implementation, completed in Lower Saxony since the beginning of 2008, the complete content of this data set is recorded. The German Basic Card 1:5 000 (DGK5) was used as an essential source for the initial recording of the basic DLM in Lower Saxony. Today, digital orthophotos (DOPs) are used to update the data. This ensures the accuracy of the road, water and rail tracks of ± 3 m.