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Revision as of 15:08, 11 April 2018
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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.
MSP Challenge 2050:
Sand & gravel extraction 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 11 April 2018, at 15:08. Content is available under GPLv3 unless otherwise noted.