Closely monitored urban development

In view of Luxemburg’s dynamic demographic and economy compared with its size, its National Plan for sustainable development (2010) has set the objective of limiting to one hectare per day the process of land take by 2020. In Luxembourg, on average 267 hectares of land per year are reported to have been sealed between 2007 and 2013.

Active conservation of the environment

With the aim of preserving greenspaces, limiting the loss of biodiversity as well as to maintaining agricultural production, the European Union has defined the ambitious objective of stopping the net increase of European land take by 2050. In order to have a more objective understanding of the phenomenon of urban development, LISER has devised a soil sealing indicator that shows the extent of the areas covered by buildings, roads, parking spaces and other constructions.

20,600 hectares of sealed soil

This indicator, calculated on the basis of aerial photographs, is estimated at 7.98% in 2013, i.e. 20,600 hectares, as compared with an estimated 7.36% in 2007. The rate of land artificialisation described in the National Urban Development Plan is probably higher, as the LISER’s indicator does not include landscaped areas such as private and public gardens, sports or leisure areas.

With the aim of preserving greenspaces, limiting the loss of biodiversity as well as to maintaining agricultural production, the European Union has defined the ambitious objective of stopping the net increase of European land take by 2050. To achieve this goal, without hampering the production of housing, infrastructure and areas for economic development, there is a need for a densification of new constructions and for the reconstruction of previously ‘artificialised’ but abandoned areas. The restoration of the initial ecological characteristics of brownfield sites is another solution that could offset the artificialisation of new land.

In Luxembourg, the challenge is to find the right balance between environmental, economic and social objectives by taking into account the demographic and economic dynamism as well as the small size of the national territory. In this context, the National Plan for sustainable development in Luxembourg (2010) has set the objective of limiting to one hectare per day the process of land take by 2020. However, the definition of the land take process, as well as its measurement by remote sensing tools, raises questions. Indeed, a cultivated field, planted to be highly productive, is considered as a ‘non-artificialised’ area according to the typologies used at the European level (CORINE LAND COVER). But can it really be considered as more ‘natural’ than an urban park, which is categorised as “artificial”? And to what extent are the tools precise enough to adequately assess the ongoing dynamics?

In order to have a more objective understanding of the phenomenon or urban development, LISER has devised a soil sealing indicator that shows the importance of the areas covered by buildings, roads, parking spaces and other constructions.

Calculated on the basis of aerial photographs, this soil sealing indicator is estimated at 7.98% in 2013, i.e. 20 600 ha. The rate was estimated at 7.36% in 2007. Between 2007 and 2013, on average 267 hectares of land per year are reported to have been sealed. This figure is not strictly comparable to the objective of the 1 hectare per day because it concerns soil sealing and not land artificialisation. The rate of land artificialisation is probably higher than the figure presented here, since artificialised areas include sealed areas as well as other areas (private gardens, squares, sports and leisure areas, etc.). In relation to population density, this rate of soil sealing seems to be high. Indeed, in the Netherlands it was estimated at 8.1% and in Belgium at 7.4% in 2010 (though these rates were calculated using other methods), whereas the population densities of these countries are approximately two times higher than the one of Luxembourg.

Moreover, the share of roads and parking spaces in the overall total of these sealed soils is much higher than that of buildings, as we can observe on the graph.