The presence of people within a territory inevitably leads to the development of artificially surfaced areas: housing, transport infrastructures, industrial establishments. However, because land is a limited resource and plays a critical ecological role as a support for ecosystems, control of its use is a major challenge for sustainable development. From this point of view, land-use management and planning seem to be essential in the search for a balance between respect for the environment and meeting the needs of present and future generations.

Discontinuous urban fabric, industrial and commercial units and major transport infrastructures represent 90 % of artificially surfaced areas. These forms of artificial surfaces are not only land-intensive, they also contribute to partitioning, reducing the areas of unfragmented land.

State and trends:

Source: UE-SOeS, CORINE Land Cover 2006.

Dominant agriculture in the North West, more natural spaces in the South and East

Forests and semi-natural areas make up the majority of the mountainous areas and the region of the Landes in south-east France; elsewhere, agricultural areas predominate. Regions such as the Nord-Pas-de-Calais and Picardy, but also Brittany and the Loire Region, appear to be both very agricultural and also artificially surfaced, with few areas available for forests and other natural environments.

The map of artificially surfaced areas is similar to that for population density:

Display of the population density map by district in 2006

The trends observed between 2000 and 2006 are a continuation of those of the 1990s, with an increase in artificially surfaced areas of 82 000 ha at the expense of agricultural land. -76 000 ha, and semi-natural areas, -10 000 ha. Artificially surfaced areas may change in use, as a result, for example, of the regeneration of vegetation or the flooding of old quarries. Water bodies continued to increase, mainly in the form of natural and artificial stretches of water.

The maps showing trends in artificially surfaced areas and population trends can be compared:

Display the map of trends in artificially surfaced areas by district from 2000 to 2006

Display of the map of population trends from 1999 to 2006 by district

A reduction in population is only rarely accompanied by a reduction in artificially surfaced areas: surfacing is not irreversible, but it is relatively rare for an artificially surfaced area to be returned to another type of use.

The Île-de-France, the north, Alsace, the Rhône corridor and the coast in general, regions with high permanent or seasonal population densities, have more artificial surfaces than the rest of the country. The increase in artificially surfaced areas occurs mainly in the vicinity of large towns and cities, and along transport networks and valleys. The total artificially surfaced area increased by 3.0 % between 2000 and 2006, mainly at the expense of agricultural land but also natural spaces.

Continuous urban fabric covers only 1.6 % of artificially surfaced land and has remained stable since 1990. Urban fabric is said to be continuous when non-linear vegetation and bare soil are rare, and discontinuous when these cover significant areas. Discontinuous urban fabric is much more space-intensive than continuous, more dense urban fabric. Discontinuous urban fabric covers three-quarters of artificially surfaced areas, and its expansion is continuing in all regions. It is expanding at a particularly high rate in the Midi-Pyrénées, along the transport routes around Toulouse, in Languedoc-Roussillon and near the coast in general. Brittany and the Loire Region, where discontinuous urban fabric was already widespread, are also in this position. In contrast, Champagne-Ardenne and Burgundy have both the lowest occupancy rates and the lowest increases in this category.

Industrial and commercial units continue to increase in all regions; by 7.2 % between 2000 and 2006. Their coverage and spread are pronounced in Île-de-France and in the Loire Region, unlike Corsica and Burgundy, where they are among the weakest.

Source: UE-SOeS, CORINE Land Cover, basis 2000-2006 changes.

The largest expansion of artificially surfaced areas between 2000 and 2006 was at the expense of cropland, but the cropland area itself expanded at the expense of pastures; this limited the reduction in cultivated area but increased the decline in pastures, which also lost space to artificially surfaced areas. The same phenomenon of returning pastureland to crops, observed between 1990 and 2000, led to an increase in the total area of cultivated land. The decline in pastureland in the second period was less but is persisting, with consequences in terms of carbon fixing. The mosaics of agricultural land are witnessing the diffuse spread of artificially surfaced land within them, as shown by comparing the total areas of zones of at least 25 ha in 2000 or 2006 with the areas affected by changes of at least 5 ha during that period.

Source: UE-SOeS, CORINE Land Cover, 2006.                            Source: UE-SOeS, CORINE Land Cover HR Soil sealing, 2006.

Artificially surfaced areas of soil have essentially been sealed; soils which have been sealed can also be found within agricultural land or semi-natural areas.

The 2006 version of CORINE Land Cover (CLC) includes a new high resolution product, which shows the degree of soil sealing per hectare and should enable the monitoring of how this changes over time. This product provides information on sealed areas, supplementing that provided by the standard CLC.

In particular, the high resolution product makes it possible to observe roads and minor artificial surfaces, including urban sprawl, thus identifying artificially surfaced areas within agricultural land or semi-natural environments. These additional areas are important within agricultural mosaics, which appear more sealed than other types of agricultural land. Comparison of sealed surfaces shown by the high resolution product with artificially surfaced areas based on the status of CLC 2006 highlights the importance of roads and scattered settlement in regions such as Limousin, Brittany, Midi-Pyrénées, Poitou-Charentes, Corsica and the Auvergne.

At the same time, the high resolution reveals the differences in the degree of sealing for different types of artificially surfaced areas. Urban green areas and sport and leisure facilities appear as the least sealed. Continuous urban fabric is much more sealed than discontinuous, less dense urban fabric. Apart from continuous urban fabric, industrial and commercial units emerge as the most sealed types of artificially surfaced land. The great expansion of these leads to as many disruptions and challenges for quantitative and qualitative regulation of the water cycle

Impacts

As well as transforming landscapes, permanent covering with artificial surfaces uses up rural and natural areas. The share of highly space-intensive forms, such as discontinuous urban fabric compared with more dense continuous urban fabric, or even industrial and commercial units, is considerable. Their expansion results in more travel, which in turn contributes to an increase in greenhouse gas emissions and air pollution.

The persistent decline in pastures, although slowing, also has consequences, since they constitute a carbon sink.

The total area of water bodies continue to increase through the creation or extension of artificial stretches of water mainly at the expense of arable land and pastures. This continuing increase results in changes in the hydrological regime and also in the types of habitats and areas represented in aquatic environments that are more fragmented. These changes are also accompanied by warming of stagnant waters, compared with flowing waters.

Turning pastures over to crops also has effects on the status of the water, through diffuse pollution which also increasingly affects groundwater over the course of time and soil erosion, increasing turbidity, silting up of substrates, etc.

Soil sealing associated with many forms of artificial surfacing contributes to disruption of the water regime and, in particular, to an increase in the risks of flooding: the increase in runoff resulting from sealing causes a further rise in water levels, and flooding occurs more quickly after rainfall. Water quality is also affected. The human and economic damage caused by the floods in the first half of 2010 has to be seen in connection with continued building in risk areas.

Display of the map showing rates of housing development on flood plains, by department. It must be viewed in relation to the cover rate in the department by the mapping of flood plains.

Uptake of land for artificial surfacing involves a decline in natural habitats. Combined with the rapid advance of linear transport networks with wide coverage, it also tends to fragment  natural environments on a large scale, which can result in the isolation and segregation of populations of animals and plants, leading to difficulties in completing their life cycles because of the reduction in the area of accessible land or the presence of obstacles. Furthermore, their capacity to adapt to climate change by shifting their ranges may be compromised.

Artificial surfacing of land on the coastal fringe

The population of coastal towns has risen from 4.8 million in 1968 to 6.1 million in 2006, an increase of 25 % compared to an average of 23 % in metropolitan France. It has risen sharply on the Atlantic and on the Mediterranean coasts, while it stagnated since 1982 and even fell slightly between 1999 and 2006 along the Channel and North Sea. Since 1968 the population of the hinterland has risen by 56 % because of the gradual spread of the population back from the sea front.

This strong human pressure is reflected in urbanisation of the coast, with artificial surfacing of land becoming more and more extensive.

Between 2000 and 2006, changes in land cover affected 1.8 % of the territory of coastal towns, compared to 0.7 % in metropolitan France. During this period, 0.3 % of the area of coastal towns (6 800 ha) was covered with an artificial surface – twice the average for France as a whole. Over the same period agricultural areas declined by 4 900 ha and forests and semi-natural areas by 2 000 ha, with the area of wetlands and water bodies remaining virtually stable.

Share of the territory affected by the changes in land use between 2000 and 2006, by major headings types

Note for readers: 0.3% of the territory of coastal towns was covered with an artificial surface between 2000 and 2006, compared to 0.15% in metropolitan France. Source: UE-SOeS, CORINE Land Cover 2000 and 2006. Processing: SOeS (Observatoire du littoral – French coastal watchdog).

Between 2000 and 2006, the highest rate of artificial surfacing occurred between 500 m and 2 000 m from the sea, representing 0.42 % of that territory. On the area closest to the sea – within less than 500 m – the proportion of land which was artificially surfaced exceeded 0.2 % in spite of the already high level of use of this land – 28 % artificially surfaced. About two-thirds of recently constructed dwellings between 1990 and 2008 are single-family homes, with many being built in less dense suburban and urban areas. Natural spaces are thus increasingly interwoven into the urban fabric, with the principal centres of nature disconnected from each other and their balance threatened.

MANAGEMENT OF CONTAMINATED SITES

There is considerable pressure to exploit industrial wastelands in urban areas. Before they can be reallocated to new uses, soil remediation operations are sometimes needed. French policy regarding contaminated sites and soils focuses on three main aspects: prevention, treatment and rehabilitation, and knowledge. Prevention is taken care of through regulations concerning scheduled establishments. Treatment is the responsibility of the industrial concerns that operate on the sites, except in the case of orphan sites where the State can itself undertake operations to secure and rehabilitate the site. Rehabilitation is based on an approach involving risk management according to the use of the sites in question. Implementation of this policy on contaminated sites and soils involves the drawing up of inventories and distribution of information on as wide a scale as possible. Two databases are currently available on the internet and can be accessed via the portal: http://www.developpement-durable.gouv.fr/Les-inventaires-BASIAS-et-BASOL.html :

• Basol, which in July 2009 compiled a register of 4 186 sites under State supervision or for which the State had taken action leading to remediation;

• Basias, which draws up an inventory of former industrial sites and service activities that may possibly be the source of contamination. In 2009 it listed 245 000 sites which had been the subject of a potentially polluting activity.

The trend in urban lifestyles within French society finds its physical expression in an expansion of towns to the detriment of natural and agricultural areas and results in a virtually irreversible artificial surfacing of land. This phenomenon of urban sprawl may be generated by an increase in the number of households – natural growth, migration or sociological trends – or by the inadequacy of the supply of housing to meet their needs. For example, households looking for increased residential space or a green living environment may leave the centre of towns and move to the outskirts. We then see an increase in density in suburban areas; housing built at a greater and greater distance from the town centre either in the form of diffuse settlement, with patchy urban sprawl, or as a concentrated settlement such as the grouped village settlements in north-east France. The cycle of property construction is no longer without consequences for urban expansion; a rise in construction may generate the demand for new sites and encourage urbanisation of land previously intended for other uses, in particular rural.

Urban expansion is not a continuous process, and the method of populating areas is influenced by public policies on urbanisation, either national or local. Within a single urban area, the municipalities may independently pursue different policies regarding urbanisation, even if there is local consultation to control expansion – for example in Grenoble, Lille, Montpellier, Nantes and Rennes. Expansion or densification of artificially surfaced areas may thus coexist at the local level.

Urban expansion contributes to the decline in agricultural land and natural environments, the main consequences being disruption of the water cycle, patchy urban sprawl in the countryside and fragmentation of environments. It also leads to an increase in travel and so plays a part in increasing greenhouse gas emissions.

Among its strategic choices, in connection with the challenge of conservation and sustainable management of biodiversity and natural resources, the 2010-2013 national strategy for sustainable development includes combating artificial surfacing and standardisation of landscapes, mainly by preserving ecological continuities and developing green and blue infrastructures between now and 2012 (Grenelle I Act, Article 24).

Through its Town Planning Code, France has many tools enabling it to manage land development.  Town planning documents covering various territorial levels – Territorial Directives on Regional Planning, Territorial Integrity Plan, Local Development Plan, etc. – allow consultation between local, regional and national authorities, with regard to regional development.

The aim of town planning documents is urban planning which ensures:

1. the balance between urban renewal, controlled urban development, development of rural areas, on the one hand, and preservation of the areas used for agriculture and forestry and the protection of natural areas and landscapes, on the other hand, while respecting the objectives of sustainable development;
2. the diversity of urban functions and the social mix in urban and rural habitats, by providing sufficient rehabilitation and construction capacity to meet, without discrimination, the present and future needs as regards habitat, economic activities – in particular commercial activities, sporting or cultural activities and activities of general interest as well as public facilities, taking particular account of the balance between employment and living conditions as well as means of transport and water management;
3. efficient and balanced use of natural, urban, suburban and rural spaces, control of travel needs and road traffic, preservation of the quality of the air, water, soil and subsoil, ecosystems, green spaces, natural or urban environments, sites and landscapes, reduction of noise nuisance, safeguarding of noteworthy urban centres and the built heritage, prevention of foreseeable natural risks, technological risks, pollution and nuisances of any kind.

Sensitive areas such as the coast and mountains have specific laws intended to restrict urbanisation.

More recently, the Grenelle I Act decided in the chapter on maintaining and developing biodiversity (article 20) to introduce measures to protect, upgrade, repair and compensate environments associated with the formation of a green and blue infrastructure, a regional development tool with which it will be possible to establish territorial continuity and to monitor and evaluate implementation and the results of these systems. The Grenelle II Act, referred to as the Act on a national undertaking on the environment, should translate these undertakings into concrete measures.

Bibliographical references:

• ‘Forêts et prairies abondent dans le réseau Natura 2000’; Le point sur...; Issue 21 - July 2009, 4 pages.
• ‘La France vue par CORINE Land Cover’; Le point sur …; Issue 10 - April 2009, 4 pages.
• The chapter on ‘L’Occupation des sols de l’Environnement en France’, Edition 2010, Références, June 2010, 148p.

These three publications can be downloaded from: http://www.stats.environnement.developpement-durable.gouv.fr/

Internet sites:

For land cover:

Service de l’observation et des statistiques (SOeS) (Observation and Statistics Service): http://www.stats.environnement.developpement-durable.gouv.fr/ > ‘Accès thématique’ [access by subject] > Then choose one of the following subjects

• ‘Territoires’ [territories]:

     -‘Littoral’ [coast]: for all matters relating to the coast and access to the mapping tools of the Observatoire du littoral.

     -‘Occupation des sols et paysages’ [land cover and landscapes]: for the statistics on land cover

•  ‘Industrie’ [industry] / ‘Pollution des sols’ [soil pollution]: for contaminated sites and soils

See also: http://www.stats.environnement.developpement-durable.gouv.fr/indicateurs/ ; heading ‘indicateurs-de-developpement-durable-territoriaux’ [territorial sustainable development indicators]

Regional development:

DATAR: Délégation interministérielle à l’Aménagement du Territoire et à l’Attractivité Régionale (Interministerial delegation for territorial planning and regional action) http://www.datar.gouv.fr. Access to the Observatoire des Territoires (Territorial Observatory) and its on-line mapping tool.

Grenelle I and II Acts and the Coastal Act:

Ministry of Ecology, Energy, Sustainable Development and the Sea:

http://www.developpement-durable.gouv.fr/