Updating the Land Use and Land Cover Database CLC for the Year 2012 - „Backdating“ of DLM-DE of the Reference Year 2009 to the Year 2006.

For the update of land cover according to CORINE Land Cover classes, a specific national approach has been chosen in Germany. This approach uses a more accurate geometry of the Official Topographical Carto-graphic Information System ATKIS of the land survey authorities. DLM-DE, derived from ATKIS, is to be applied as base for the deduction of CLC classes. In the responsibility of the German Federal Agency for Cartography and Geodesy (BKG), the DLM-DE 2009 database was built-up for the reference year 2009 with a minimum mapping unit (MMU) of 1 ha. Currently, an updated DLM-DE 2012 database is established by BKG; using methods of generalization this database will be transferred into the CLC2012 database (CORINE Land Cover 2012, having 25 ha MMU due to the EU specifications). Besides CLC2012, a change layer of land cover between 2006 and 2012 is needed, describing the develop-ment of land cover categories (with 5 ha MMU). Due to the methodological modification, the change layer cannot be deduced directly by BKG using the conventional CLC2006 and DLM-DE 2012 or the resulting CLC2012. Direct changes can be achieved only by comparing DLM-DE 2009 and DLM-DE 2012 for the period from 2009 to 2012. Therefore, the task of DLR-DFD in this project was to model changes between 2006 and 2009 in the detailed geometry of DLM-DE 2009. A database „CLC2006_Backdating” had to be created by a backward look from DLM-DE 2009 to the situation of land cover / land use in 2006. This has been done using an approach starting by the most common 46 change classes (based on the changes between 2000 and 2006).