Impervious surface

Surface sealing or soil sealing refers to the covering of the natural soil by buildings of the people. From surface sealing is therefore spoken, because in the bottom of the top no more precipitate can penetrate and so many of there normally occurring processes are stopped. For sealing of invisible structures are counted under the earth's surface, such as pipes, ducts, foundations and highly compacted soils.

Problem

Soil sealing has a negative impact on the natural water balance, since the soil is no longer used as a buffer. The superficial runoff is increased and decreased groundwater donation. This can lead to lack of drinking water, increased drought damage and stronger flood. The groundwater contamination and concentration can rise, since selective infiltration of precipitation less nutrients and pollutants can be filtered in the soil.

" Underground seals " as tunnels or particularly deep cellars may adversely affect, especially on slopes, the flow behavior of groundwater.

Primary will be the construction of roads, paved paths and squares, houses, commercial and industrial applications free surfaces sealed in such a large scale that seeps far less surface water (rain water).

In inner cities, towns and surrounding metropolitan areas at times large portions of the floor are sealed. In some places were or are there urban sprawl (see also suburbanization ); New buildings have a certain land use. In Germany, new roads are rarely built; also airports and new railway lines are rarely built.

Secondly, the consequences of sealing mingle with those of consumption of landscape and land use. Especially the road prevents the ability to partition the landscape the free mobility of terrestrial creatures, so they are cut off from food sources, breeding or spawning grounds and genetic depletion occurs by forced inbreeding. Likewise, the spread of the natural flora by sealing is prevented. The individual causes are to be separated in their consequences not always.

Another problem of sealing is that the predominantly dark impervious surfaces ( asphalt) absorb a lot of heat. So it is in the summer to excessive heating of the city.

Countermeasures

To counteract the sealing, the federal government is working with the instruments of spatial planning and urban planning. The Spatial Planning Act and the Land Use Plan Write the land before, which may be built on.

When unavoidable construction with large area sealing ecological compensation areas should be established. Intervention in nature and landscape can thus compensate elsewhere. This field margin hedges and lean lawns are planted, created wetlands and streams renatured. These habitats are of conservation point of view very valuable, as they are very rich in species.

In fact, sealed surfaces

The survey of the actual built-up area is very difficult. On the part of the statistical offices is not charged soil sealing. The Federal Office for Building and Regional Planning and the Environment Agency estimate that about 50% of the settlement and traffic area of ​​the Federal Republic of Germany are sealed. The settlement and traffic area in turn is collected by the statistical offices in the statistics of actual land use. For settlement and transport area include:

  • Buildings and building-related areas for uses such as housing, trade, services, business, industry and waste disposal,
  • Recreational areas (sports grounds, campsites),
  • Traffic areas: streets, roads, squares, railway premises, airports,
  • Operating areas without mining land ( Halden, storage ...) and
  • Cemeteries.

These areas cover a total of approximately 12.5 % of the floor area of ​​Germany, of which 50% are sealed again after the above estimate. For this purpose, but there are further sealed surfaces, which are not included in the settlement and transport area ( for example, forestry or agricultural buildings ).

A common mistake is equating the settlement and traffic area with a sealed surface. For example, include the " buildings and open spaces " not only sealed surfaces, but also home gardens. For accurate survey of the sealed surfaces so far no method has generally prevailed. In this context it should be noted that the daily land consumption of approximately 81 hectares ( as of 2011) does not indicate that daily 81 hectares are sealed, but the daily 81 hectares of agricultural or natural embossed surface are converted into settlement and traffic area. As a result of this conversion there is a variable degree of sealing.

Flood

The Mirror asked the occasion of the floods of 2013 in southern Germany, East Germany and Central Europe Is the paving of the ground fault? and came to the conclusion

"Hardly. Rainfall, which can rise big rivers such as the Elbe or the Rhine, flows from an area that is almost as big as half of Germany. But only one-tenth the size of Germany is sealed artificially with asphalt or buildings. A view of the landscape reveals the real problem: The rain itself seals the base, fields and meadows are currently inundated by vast lakes.

This was caused by heavy rainfall in a short time: many places fell more than 300 liters in four days, the water is then 30 inches high, if it does not flow. The rain fills all the pores in the soil so that rain can not seep further - the water flows directly into rivers and streams. 40 percent of the land area of Germany had the end of May exhibited new soil moisture records, reports the Center for Disaster Management and Risk Reduction Technology ( cedim ). In many places, one of May to the wettest since records began a century ago. "

Footnotes

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