Ratios and indicators are calculated for spatial units at diverse levels over the territory of the Federal Republic of Germany (not including marine areas). The indicator values are generally based on administrative units (municipalities, districts, states) as well as spatial planning regions (so-called Raumordnungsregionen). If a municipality has onshore or coastal expanses of water then these areas are included in calculations. The cartographic illustration always indicates coastal lines but not borders around lakes or reservoirs.
Presentation is also by means of raster maps at cell resolution 100 m, 200 m, 500 m, 1 km, 5 km and 10 km. This enables an inter-communal evaluation of settlement and landscape structure. The raster maps are independent of changes to administrative boundaries and thus allow the creation of stable time frames. It should be noted that with increased resolution (smaller raster width) ratio and indicator reliability decreases due to geometrical imprecisions and disparities in data topicality.
Determined at municipal level, Germany’s total land mass is 357,674 km2 according to national geobasis survey data issued for the first time on 31/12/2013 (administrative boundary VG25, BKG 2014). For previous timeframes of the IOER Monitor, geodata was created for the administrative units on the basis of ATKIS Basis-DLM (for method cf. Schumacher, Krüger und Kaden 2013: Gebietsreformen und Verwaltungsgrenzen: Zum Aufbau einer Verwaltungsgebietsgeometrie VG25 aus dem ATKIS-Basis-Landschaftsmodell. In: Kartographische Nachrichten 63(2013)5, 276-282). In some cases there are disparities in the calculated area of individual coastal municipalities for 2013, which can be attributed to the shifting coastal boundary over previous timeframes. This results in some minor differences in the calculated land mass of Germany in previous Monitor timeframes compared to the above-mentioned figure.