Text from the Indicator Report 2022
Open space area includes areas of vegetation, such as arable land, pasture and woodland, as well as mining land and bodies of water. A distinction is made between open space proper and open areas within settlement zones, such as cemeteries, gardens, parks and recreational amenities, which, although largely undeveloped, are generally considered part of settlement and transport area. As a result, if previously undeveloped parts of settlement land are built on, this is neither reflected in this indicator 11.1.b “Loss of open space area” nor in the indicator 11.1.a “Expansion of settlement and transport area”.
In the period under review, the national average for per capita loss of open space area went down. Whereas the four-year moving average for 2001-2004 was still around 5 m² per capita, the current four-year moving average for 2017-2020 reveals a figure of just 3 m².
Although subject to a similar trend, significant differences can be observed between rural and non-rural areas in terms of the degree of change. The loss of per capita open space area per inhabitant in rural areas contracted from 7.4 to 4.5 m² per year. In non-rural areas, it fell from 1.8 m² to 0.7 m². In this context, it important to remember that non-rural districts and district-free cities have much less open space, such as forest or farmland, than rural areas do. Demographic trends also differ, and the indicator reflects those disparities, with rural areas mostly seeing their populations shrink during the period under review, while population numbers in non-rural areas rose slightly overall.
The data sources for the indicator are the population figures and the area survey by type of actual use compiled by the Federal Statistical Office. Since population data at regional level are used for the associated calculations, the 2011 census caused a jump in the time series. Moreover, some areas of land have been reclassified in the official land register maintained by the Länder in recent years, without any actual change to the landscape. To smooth out these effects and depict the long-term trend, a four-year moving average is shown, averaging out the figures for each year with those for the three preceding years. Additionally, the switch from the old to the new land use classification system was completed in 2016, which affected the official land-use statistics such that the data for 2016 are not directly comparable to those for previous years. This is why the development of the indicator for 2016 is only shown as a broken outline in the graph.
The distinction between rural and non-rural is based on a classification used by the Thünen Institute. The institute ascribes a degree of rurality to districts and district-free cities on the basis of geographical characteristics such as settlement density and share of farmland and woodland. The classification is thus applied to whole districts rather than to smaller entities like towns or villages.