Shoreline response of eroding soft cliffs due to hard defences

Authors: Brown, S., Barton, M.E. and Nicholls, R.J.

Journal: Proceedings of the Institution of Civil Engineers: Maritime Engineering

Volume: 167

Issue: 1

Pages: 3-14

eISSN: 1751-7737

ISSN: 1741-7597

DOI: 10.1680/maen.11.00026

Abstract:

Soft cliff retreat has often triggered a hard adaptation response by the building of seawalls and groynes. On adjacent undefended coasts erosion continues, resulting in set-backs. This paper examines the impact of coastal defences on the adjacent coast from historic records and present practices, and explores possible future response. Continued setback often leads to outflanking of defences, making them ineffective at their extremities, particularly at the downdrift end where it is most severe. Solutions to outflanking usually involve extending defences, initiating a cycle of set-back, outflanking and further extensions. Multiple defence extensions and continued retreat of the unprotected adjacent coast results in artificial headland formation. Over several decades, headlands experience foreshore steepening and reduced sediment availability, making them more difficult and expensive to defend. Shoreline management plan policies of managed retreat advocate selective defence abandonment, which may change the nature of artificial headland formation. Defence abandonment and new engineering works must be planned, anticipating the processes described in this paper. This will reduce unexpected changes and reduce maintenance and emergency work costs.

Source: Scopus

Shoreline response of eroding soft cliffs due to hard defences

Authors: Brown, S., Barton, M.E. and Nicholls, R.J.

Journal: PROCEEDINGS OF THE INSTITUTION OF CIVIL ENGINEERS-MARITIME ENGINEERING

Volume: 167

Issue: 1

Pages: 3-14

ISSN: 1741-7597

DOI: 10.1680/maen.11.00026

Source: Web of Science (Lite)