Soils in the built environment
Soil sealing
Urban development and construction of transport infrastructure are the main causes of almost irreversible net soil loss.
Development places severe restrictions on the ability of soil to support other functions in the future.
The soil may be severely damaged, completely removed or covered (sealed).
Soil sealing can be defined as:
- The covering of the soil surface with an impervious material or the changing of its nature so that the soil becomes impermeable. The soil is no longer able to perform the range of functions associated with it.
or:
- The separation of soils from other compartments of the ecosystem by layers and other bodies of completely or partly impermeable material.
Impact of soil sealing on soil functions
Most sealed soils perform only the platform for construction function of soil, ie. supporting buildings.
Soil sealing prevents the soil from performing other functions such as food and fibre production or the ecological functions of soil, including storage of carbon and as a habitat for unique biota.
The indirect impacts of soil sealing affect large areas due to fragmentation of habitats and disruption of ecological corridors.
- For more detail, see the soil functions pages
Monitoring soil sealing
There is currently no monitoring of the levels of soil sealing. Soil sealing will occur on all sites where development takes place, but these sites will not be totally sealed.
Defra and the British National Space Centre (BNSC) are funding a project on the application of remote sensing to identify and measure changes in the area of soil prevented from carrying out functions by sealing (SP0541).
Case study: London Borough of Ealing - hard surfacing of front gardens
The hard surfacing (sealing) of front gardens to provide off-street parking has been on the increase in recent years.
In the London Borough of Ealing there has been concern that this sealing of front gardens is becoming a serious environmental and social issue.
Ealing's Local Agenda 21 group funded research to determine the scale of the problem. The research was published in 2004.
Since the publication of this report Ealing Borough Council has further developed their list of problems caused by hard surfacing of front gardens.
This issue has also been identified by the London Assembly in their report highlighting the environmental importance of front gardens in London and by the Royal Horticultural Society, in a leaflet on front gardens.
- Crazy Paving: The environmental importance of London’s front gardens – September 2005
- Front Gardens: Are we parking on our gardens? Do driveways cause flooding?
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Page last modified: 7 April 2006
Page published: 1 September
2005