The term "urban sprawl" refers to the uncontrolled spread of towns and villages into undeveloped areas. It has a negative impact on the beauty and specific character of the landscape, and thus affects not only regions used for tourism and recreation, but also the quality of residential zones. Urban sprawl gives rise to a broad variety of negative ecological, aesthetic and economic impacts, including high infrastructure costs, growing numbers of commuters, the loss of habitats for flora and fauna, and monotonous structures.
Urban sprawl increased rapidly in the period from 1935 to 2002, especially between 1960 and 1980. The most rapid increase was in the Central Plateau (Mittelland), followed by the Jura region, while the rates of development in the Central Alps and in the Northern and Southern Alps were considerably slower. However, the comparatively positive figures for the three Alpine regions are deceptive in that very extensive areas of the Alps cannot be developed at all (mountainous terrain, rock faces, glaciers, etc.). The current situation therefore has to be described as alarming.
In addition to the growing population, one of the main causes of increasing urban sprawl is the ever more widespread spatial separation of employment, home and recreation.
Over the past 80 years, urban sprawl has even increased (admittedly at a considerably slower pace than in the remainder of the country) in protected areas such as landscapes and natural monuments of national importance, mire landscapes of exceptional beauty and national importance, and nature reserves and national parks.
The indicator is based on a new measurement criterion - urban sprawl, which was formulated within the scope of National Research Programme 54, "Sustainable development of the built environment". With this criterion it is possible for the first time to quantify uncontrolled development (urban sprawl) and measure it for the entire country.
Weighted urban sprawl is based on three measurement criteria: distribution of developed areas (dispersion, DIS), urban penetration (UP), which takes the developed area into account and population and employment density (utilisation density, AD). These criteria are combined and weighted in order to measure the degree of urban sprawl. In this way it is possible to compare landscapes of different dimensions.