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IABG updates digital landscape model of Germany - DLM-DE 2012

In April 2013 IABG was contracted by the German Federal Agency for Cartography and Geodesy (BKG) to update the Digital Landscape Model of Germany (DLM-DE 2012). The geodata to be updated and amended on the Federal Republic of Germany extends over a surface of approximately 360,000 square kilometres. In IABG’s production centre – the "geodata factory" in Dresden – mapping experts update the DLM-DE 2012 on basis of satellite imaging data. Starting point for the update are the processed ATKIS® volume data (ATKIS = Official topographic-cartographic information system) and the DLM-DE 2009 which was developed in cooperation with IABG. The project is to be completed by February 2014.

 

In contrast to the DLM-DE 2009, which was still prepared on basis of the Corine Land Cover (CLC) system, a land coverage and land use code is allocated to all objects in the 2012 update. By using this differentiation developed by BKG complex landscape structures can be represented with highest accuracy in the DLM-DE 2012. The minimum mapping surface is 1 hectare, the minimum mapping width 15 metres. Factual and geometrical changes, which so far were no DLM-DE components, are now concretely mapped. Existing objects are verified and corrected as necessary.

 

Recent extensions of settlements and industrial areas as well as changes in forest, field and grassland surfaces are being mapped. The data is examined and updated using highly efficient, semi-automatic data processing tools which allow saving time and costs and ensure data quality. On basis of the BKG project manual IABG developed a detailed mapping guide to guarantee a homogeneous and efficient evaluation. In addition to the actual mapping, the implementation of data base schemes and the creation of a quality assurance concept are among the tasks at hand. The development of suitable software tools contributes both to an efficient mapping process and to the quality assurance. Compared to the 2009 version, the necessary quality level was increased to a total accuracy of 97.5 per cent.

 

Primary data source for the mapping process is, as in 2009, the German satellite constellation RapidEye. 750 tiles sized 25 x 25 kilometres are necessary to cover Germany. RapidEye AG delivered good preliminary results so that the best scenes could already be pre-selected. Data acquisition is limited to the vegetation period of 2012. Data from the European GMES programme (GMES = Global Monitoring for Environment and Security) is hereby used as well. This free data represents a major increase in value, in particular for forest differentiation purposes.

 

A geodata record is thus being developed for Germany which can be used in versatile application forms in the sectors of environment, land and forestry, water protection, traffic, security and spatial planning. Especially for interdisciplinary issues requiring precise measurement and environmental information, the new DLM-DE represents a state-of-the-art and solid basis. Based on the land coverage and land use codes of the new DLM-DE, the classes of the Europe-wide land use mapping system CORINE Land Cover (CLC) are subsequently derived by the BKG in a fully automated procedure thus guaranteeing that the Federal Republic of Germany meets its obligation to report the 2012 CLC data record to the European Union by summer of 2014.