FD1912 - SANDPIT: Effects of offshore dredging

Theme:Strategy and Policy Development
Project status:Completed
Start date:01/11/2001
End date:30/04/2005
Keywords:
  • Coastal Defence,
  • Processes,
  • Land,
  • Flood and Coastal Defence,
  • Environmental Protection
Contractor:
  • HR Wallingford Ltd
Contact:

PROJECT CLOSING STATEMENT:


The

SANDPIT

project was a European collaborative research project aimed at strengthening the scientific background against which offshore sediment dredging applications are reviewed. The project addressed questions focused especially on the hydrodynamic, sediment dynamic and morphodynamic impacts of marine sand extraction, and the time-scales over which they apply. The detailed and practical results from the project have been published in a hardbound book of c.600 pages – “

SANDPIT

: Sand Transport and Morphology of Offshore Sand Mining Pits” ISBN 90-800356-7-x – which is available from the website of the publisher (www.aquapublications.nl).

Key results include:
1. Estimates of gross and net annual sand transport rates have been determined for four contrasting sites in the North Sea, English Channel and Atlantic Ocean. A unique set of field data of depth-integrated transport rates in deep coastal water has been obtained for validation of predictive models.
2. A quantitative assessment of the impacts of large sand extraction pits, both in the vicinity of the pit and at the nearby coastline
3. Guidelines are given on the rate of recovery of sand banks following mining activities
4. The key effects of aggregate extraction on sea-bed ecology are collated from a limited literature review. Impacts in sandy habitats are generally believed to be less than in gravel habitats.

The project outputs should be studied by anyone concerned with the regulation of offshore mining of sand and aggregate, and technical advisers who try to predict environmental effects of this activity. The failure of model simulations in particularly should be noted as a warning against over-reliance on computer predictions in decision making.


SUMMARY OBJECTIVE:


To develop guidelines and prediction techniques to assess the effects of offshore aggregate dredging (and similar disturbances to sediment)on the adjacent coastline in terms of stability of near-shore and beach morphology, flood defence, erosion and ecological issues.

KEY

CUSTOMER PURPOSE:


To deliver a course on sand transport and the effects of aggregate extraction for end users.