No edit summary |
No edit summary |
||
| Line 29: | Line 29: | ||
* In the second method, a trailing suction hopper dredger removes sediment from the surface of the sea floor. The dredger is pulled along the sea floor like a vacuum cleaner and leaves behind a furrow between 2 and 4 m wide and up to 0.5 m deep. | * In the second method, a trailing suction hopper dredger removes sediment from the surface of the sea floor. The dredger is pulled along the sea floor like a vacuum cleaner and leaves behind a furrow between 2 and 4 m wide and up to 0.5 m deep. | ||
Source: | Source: BFN, German Federal Agency for Nature Conservation | ||
===MSP Challenge 2050:=== | ===MSP Challenge 2050:=== | ||
Revision as of 14:20, 13 April 2018
| Layer Info | |
|---|---|
| Category | Shipping |
| Editable | Yes |
| Data source | Estimations & data fragments |
| Types | |
Description:
Methods of extraction
Typical purposes of sand or gravel extraction can be to obtain useful material (for e.g. heightening beaches, or in building or infrastructure development), and/or to deepen the sea in a particular area (e.g. a fairway to allow large cargo or tanker vessels with deeper drafts to enter a port).
There are two main methods of extracting sand and gravel:
- In stationary extraction, an anchored cutter suction dredger excavates huge pits in the sea floor with depths of normally about 10 m and diameters of between 10 and 50 m.
- In the second method, a trailing suction hopper dredger removes sediment from the surface of the sea floor. The dredger is pulled along the sea floor like a vacuum cleaner and leaves behind a furrow between 2 and 4 m wide and up to 0.5 m deep.
Source: BFN, German Federal Agency for Nature Conservation
MSP Challenge 2050:
Sand & gravel extraction areas are polygons, i.e., geometric shapes that you can draw in, edit or remove when making a plan.
Sand & gravel extraction areas create the following pressures on the ecosystem:
- Bottom disturbance
- Noise
IN THIS TAB EXTENDED CONTENT IS PLACED
ON THIS TAB VISUAL CONTENT IS PLACED
This page was last edited on 13 April 2018, at 14:20. Content is available under GPLv3 unless otherwise noted.
Co-funded by the European Union.