The maps of both the urban structure mapping system and those of the actual use mapping system used the block maps of the City and Environment Information System (ISU) as the spatial reference system, and have been updated together. For the 2011 Edition, changes in land use between 2005 and 2010 have been ascertained, and updating of the geometries of the 1:5000 (ISU-5) block maps undertaken. The updating of the urban structure maps was generally carried out after that for the actual use maps, i.e., the block sections and block segments were in principle not subdivided further. The assignment of section types is generally undertaken by means of visual examination on the basis of current aerial photography and of the map of Berlin (K5) for block sections where the uses which cannot automatically be assigned to a certain section type.
For areas assigned both to the Map 06.01 Actual Use of Built-Up Areas and to Map 06.02 Green and Open Spaces (dual use), there are generally two possible approaches:
a) type assignment is carried out in accordance with structural use
b) type assignment is carried out according to green and open space use.
Previously, the data stock was structured in such a way that dual use areas were assigned to the section type of green and open space use. That meant that for these areas, the actual building structure type (structural use) could no longer be determined. For instance, a hospital, a Public facilities/special use area with dual use as a Park/green space, was mapped under the section type Parks/green spaces, and was thus no longer identifiable as a hospital. As a result, section type information from dual use blocks no longer permitted any statements to be made as to the actual use of those areas.
In the current revision, this approach has been changed, so that the building structure for all structural uses can also be directly ascertained from the section type. The reason for this methodological change is that the section types of building uses are more strongly differentiated than those for open space uses, for which a direct transfer to the corresponding category of section types is then carried out. For the above example, that would mean that the corresponding block section would now be assigned to the section type Hospitals, so that a further differentiation with regard to the use mapping process would be carried out. All areas with dual use have been re-categorized accordingly. For those blocks for which dual use has been assigned, the type determination has thus in effect been carried out with priority for the buildings, i.e., the section type is fundamentally oriented toward the structural use. An exception here is sports use, which is counted as open space use, and is always categorized as dual use together with Public facilities/special use. In type categorization, covered and uncovered sports facilities are distinguished, with the latter assigned to the group Open space use section types.
Updating of the geometry and the use data
The updating of the urban structure mapping system is carried out parallel to the revision of the actual use maps of the Environmental Atlas (06 .01 Actual Use of Built-Up Areas and 06.02 Green and Open Spaces).
In addition to the main emphasis update, which is carried out regularly at five-year intervals, the revision for the 2011 Edition focussed on a more far-reaching, partially automated update of the entire database, based on geo-data available in the State of Berlin, as well as a revision of mapping units, both of the actual use and of the urban structure mapping systems. Moreover, the rules for the admissibility of combinations of various land uses and section types was revised, and the plausibility check for the entire database was carried out on the basis of these rules.
Revision of mapping units and of the ascertainment system
The description of the mapping units was subjected to an extensive check, and to some extent adapted to the changing database. For instance a number of mapping units which continued to distinguish between East and West Berlin, were either combined to form uniform categories, or were remapped. In this process, nine section types were abolished, and each was assigned completely to another category. Four other section types were abolished, and the respective areas were in each case apportioned among a number of other categories. Six other section types were selectively re-mapped.
The plausibility checks consisted of a database analysis, under which areas with non-admissible combinations of uses and section types were ascertained and examined, and of an evaluation of various geo-data stocks which have been compiled in recent years at the Senate Administration for Urban Development for various purposes. These data stocks were either already available as block data of the ISU, or else could be merged and compared with the data of the ISU maps, thus providing possibilities which permitted particular cases of use information to be re-examined. For instance, based on existing data on the Land-to-Building Ratio (LBR), the assignment of the blocks of the section types Commercial/industrial areas with dense or sparse construction could be examined. The LBR indicates the built-up proportion (cf. §19 Sect. 1 Land Use Ordinance). For this reason, commercial and industrial areas were checked to make sure that their LBR was greater or less than 0.5 (i.e., occupation by structures of more or less than 50%), respectively, in accordance with their classification as dense or sparse construction.
In the current revision, 6239 areas of the total of 24,961 contained in the ISU-5 block map were checked. Of these, 5010 areas were assigned to a new use category, and as a result, to a new section type. The changes involved a total of 23% of the entire area of Berlin.