Every year in Europe, soils covering an area larger than the city of Berlin are lost to urban sprawl and transport infrastructure. This unsustainable trend threatens the availability of fertile soils and groundwater reservoirs for future generations. Soil sealing (its permanent covering with impermeable layers of buildings, asphalt roads, parking lots and so on) causes an irreversible loss of the ecological functions of soil. As water can neither infiltrate nor evaporate, water runoff increases, sometimes leading to catastrophic floods. Cities are increasingly affected by heat waves, because of the lack of evaporation in summer. Landscapes are fragmented and habitats become too small or too isolated to support certain species. In addition, the food production potential of land is lost forever. The Commission's Joint Research Centre estimates that four million tonnes of wheat are potentially lost every year to soil sealing.
Between 1990 and 2000, at least 275 hectares of soil were lost per day in the EU, amounting to 1,000 km² per year, with half of this soil being sealed by layers of concrete and asphalt. This effectively means that every ten years an area the size of Cyprus is paved over.
Although the trend has apparently been cut back to 252 hectare per day in recent years, the rate of land consumption is still worrying. Between 2000 and 2006, the average increase in artificial areas in the EU was 3%, with figures exceeding 14% in Cyprus, Ireland and Spain. Regions all over Europe are affected by increasing soil sealing.
With a view to achieving the objectives of the Soil Thematic Strategy and the proposed Soil Framework Directive, which aim to protect European soils from degradation and to contribute to resource efficiency, the European Commission ordered a report entitled 'Overview of best practices for limiting soil sealing or mitigating its effects in EU-27' from the Austrian Environment Agency, which was completed in April 2011.
The report is based on information received from experts dealing with spatial planning, soil protection, building techniques, and on research from all over the EU. It briefly reviews the state of land take and sealing in the EU and gives an exhaustive overview of existing Member State policies to reduce and mitigate soil sealing. It presents the technical measures taken to mitigate the effects of sealing as well as the compensation systems introduced. These are supplemented by information on soil quality criteria and existing networks with relevance to the reduction of sealing.
The report recommends a three-tiered approach:
Compensating valuable soil losses by action in other areas to offset drawbacks in eco-function. Measures may take the form of payments, as in the Czech Republic and Slovakia, or the restoration of already sealed soil. Good practices have been identified notably in the cities of Dresden (Soil Compensation Account) and Vienna.
The report is also available section by section:
A press release is available here.
One of the authors of the report (Gundula Prokop) appears at Green Week 2011 in the session 'Soil sealing, floods and fragmentation – an avoidable catastrophe?'. Her presentation as well as those of the other speakers will be available here.
The report will serve as a basis for a Technical Document on Soil Sealing in the EU drawn up with the help of nominated national experts. The document will provide national, regional and local authorities with guidance on best practices for limiting soil sealing and mitigating its effects. The final document is expected to be ready in the course of 2012.