Environmental Engineering Reference
In-Depth Information
the United Kingdom unwanted Christmas trees have been dumped on the dunes as
a means of trapping wind-blown sediment.
In addition to locally applied 'soft' measures of erosion management, more
strategic approaches can be applied over greater geographical and temporal scales.
Managed retreat (or realignment) is becoming a greater consideration within in
coastal management. Retreat involves major changes to land use and relocation
of homes and infrastructure under threat (Few et al.
2007
). Currently, managed
retreat is applied mainly to estuarine environments and motivated by habitat crea-
tion, reducing the costs of flood protection and mitigating environmental impacts
of coastal development. Managed realignment is being widely advocated in the
United Kingdom for the alleviation of flood risk (Cooper
2003
), and has been used
in England and Germany (Rupp-Armstrong and Nicholls
2007
). Methods include
artificially created breaches in previously constructed embankments (Symonds and
Collins
2007
) and managed retreat of a previously developed or defended coast-
line (Cooper
2003
). In Northern France and Belgium breaches have been made
through dunes behind beaches so that the sea can enter through the barrier, reduc-
ing local erosion (Charlier et al.
2005
). Managed retreat requires setting back
coastal defences inland, and can have significant impacts on natural processes
(French
1997
,
2008
).
In addition to 'soft engineering' more strategic coastal management, such
as land use planning controls, can be employed to restrict future development
in the coastal zone. For example in Australia setback lines of a selected distance
for development projects are incorporated in planning policy (Walsh et al.
2004
).
Coastal construction setback lines, which limit new development in areas of high
hazard, are used in many coastal programmes in the United States (NOAA
2000
).
By 2005 there were 466,620 ha (1,152,551 acres) of barrier islands 'protected' by
United States law, but the Acts of Congress of 1982 and 1990 do not actually for-
bid development, they merely warn would-be builders that they cannot count on
the Federal Government to provide insurance or reconstruction funds in case of
damage due to storms, floods and erosion (Charlier et al.
2005
).
References
Ahrens JP (1990) Dynamic revetments. In: Edge BL (ed) Coastal engineering 1990—pro-
ceedings 22nd coastal engineering international conference, Delft, The Netherlands, pp
1837-1850
Basco DR, Bellomo DA, Hazelton JM, Jones BN (1997) The influence of seawalls on subaerial
beach volumes with receding shorelines. Coast Eng 30:203-233
Bruun P (1995) the development of downdrift erosion. J Coastal Res 11:1242-1257
Charlier RH, Chaineux MCP, Morcos S (2005) Panorama of the history of coastal protection. J
Coastal Res 21:79-111
Cooper NJ (2003) The use of 'managed retreat' in coastal engineering. Eng Sustain 156:101-110
Few R, Brown K, Tompkins EL (2007) Climate change and coastal management decisions:
insights from Christchurch Bay, United Kingdom. Coast Manag 35:255-270
French PW (1997) Coastal and estuarine management. Routledge, London
