Land use - Drivers and pressures (Germany)

Take-up of land by private households

Although the German population has declined over the past few years, clear growth has been observed in the settlement and traffic area. One especially significant factor for land use is the increase in the living area per inhabitant and the construction of private residences on green-field sites, which currently account for around one third of newly developed areas.

Private households occupy 52 % of the settlement area. This area is used mainly for residential purposes – the settlement area of private households not used for residential purposes includes recreational areas, allotments and graveyards.

Between 1996 and 2004, the settlement area occupied by households for housing, leisure or public services increased by 15.9 %. The building and adjacent open area (houses with their yards and gardens) used for residential purposes only increased rather less, by 14.4 %. It may be noticed, that space consumption by one-family houses is far more important than space consumption by many-family houses. While the rate of construction of one-family houses in the old Länder roughly follows demographic trends, in the new Länder from 1994 to 2004 there happened a temporary boom of urban sprawl due to the accumulated demand of people, following the ideal of an own house with garden.

In comparison, the living area actually used inside dwellings increased by 13.8 % between 1995 and 2006. Various factors play a role in the rather different development of the living area actually used and the built-on and open-air areas used for residential purposes. These include an increasing proportion of vacant dwellings, a significantly increasing proportion of more space-intensive one-family houses among new-builds, and an increasingly dense concentration of buildings, in particular in inner-city areas.

The number of one-person and two-person households has each increased by around 12 % in the past decade, while the number of households with three and more persons decreased by 7 %. The trend towards smaller households is having an adverse effect on the utilisation of living space. The living space per person in one-person households, 62.5 m², is significantly higher than in two-person households – 43.4 m². The members of households with three and more persons use an average area of only 28.5 m².

The spread of settlements is accompanied by the familiar environmental consequences of land use change such as loss of fertile soils, increased traffic generation and increased material and energy consumption. However, the currently observable trend towards a decrease in population and an increase in vacant dwellings and industrial wasteland should not be taken to indicate associated proportional environmental relief, since many buildings as well as supply and transport infrastructures continue to exist even in the face of a shrinking population. These still need to be operated, serviced and maintained. This results in increasing ecological pressures per head of the population. But there are also economic pressures per head of the population, because the buildings and infrastructures serve increasingly fewer users and must be paid for by them.

The requirements which responsible settlement planning and housing policy will have to meet in the future are, on the one hand, bringing about the most space-saving, environmentally and socially acceptable settlement development possible in regions that are still showing sustainable growth and, on the other hand, implementing the most cost-effective, environmentally and socially acceptable adaptation possible of the buildings and infrastructures to meet future needs in stagnating or shrinking regions.

Fragmentation and isolation of habitats by growing settlements and traffic

The increasing use of land in Germany for settlement and traffic is not only leading to permanent consumption of landscape, but also having a far-reaching adverse effect on the functionality and efficiency of ecosystems and the landscape. For the majority of animal and plant species, any further fragmentation and isolation by the traffic routes will mean an irreversible loss of natural habitat.

The length of inter-urban roads in Germany increased between 1991 and 2006 by around 4 700 km from 226 700 to 231 400 km. In contrast, the German Federal Railways network contracted by 7 200 km between 1991 and 2006 – from 41 100 to 33 900 km.

Whereas the decrease in the rail network is mainly attributable to branch line closures, the decrease in federal highways is mainly attributable to the fact that these have been re-designated as highways of the federal states (Länder) or as regional or local main roads. The traffic burden on these roads has admittedly been relieved, by the construction of a parallel federal motorway, but even after reclassification they continue to be used as quite important trunk roads with corresponding traffic volumes.

Depending on the traffic volume, local main roads can also have a fragmenting effect.

Between 15-20 % of the growth in traffic can be attributed to the expansion of traffic infrastructure – so called ‘induced traffic’. In the field of freight transport such expansion causes transport costs to fall, with the result that outsourcing, ‘just-in-time’ deliveries, etc., continue to be profitable. In the field of passenger transport, the journey time saved through an improved infrastructure in turn leads to more traffic. The length of the single trips covered has thus been increasing for years, although not the actual number of trips. The expansion of the road network also causes shifts in the modal split towards less environmentally friendly modes of transport.

In contrast, sustainable and environmentally compatible spatial development calls for the maintenance of large unfragmented areas that are not negatively affected by traffic.

In order to provide animal species that need a lot of space, such as the red deer, lynx or wildcat, with sufficiently large habitats and also to make recreational areas available for people, in which motorised traffic produces neither visual nor an acoustic negative effects, the Federal Government aims to preserve the current share of total unfragmented land not negatively affected by traffic at 100 km² at least.

In 2005, 26 % of the surface area of Germany (94 427 km²) was covered by unfragmented low traffic areas (UZVRs) with an average size of 168 km². In the east, the percentage of land area accounted for by UZVRs – 23 % in Saxony and up to 64 % in Mecklenburg-Western Pomerania – is significantly above that of the federal states in the west of the country – 4 % in North Rhine-Westphalia and 36 % in Lower Saxony.

The UZVR indicator is supplemented by the effective mesh size indicator (Meff in km²), which shows the mean degree of fragmentation of the land area. The effective mesh size is an estimated mean value of the mesh size of the traffic network, which, in addition to the size of all the UZVRs, also takes account of the structure of the fragmentation of the entire region under consideration.

The use of the two partial indicators combines the advantages of both methods:

• UZVRs: large unfragmented low traffic regions > 100 km² are apparent as areas that merit special protection and are readily identifiable;

• Meff: a wide-area indicator that is particularly relevant in regions in which scarcely any large unfragmented low traffic regions remain.

Distribution of UZVRs and values of the effective mesh size (Meff)

Unfragmented low traffic regions can also have a positive effect on the urban climate as a result of improved air circulation and air exchange in the immediate vicinity of densely populated urban areas. It is also important to maintain open spaces that are extensively unfragmented and not exposed to noise pollution to enhance people’s experience of nature.