Seychelles Damage, Loss, and Needs Assessment (DaLA ... - GFDRR

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Seychelles Damage, Loss and Needs Assessment (DaLA) 2013 Floods
Figure A3.3 Time Series of Mahé Island Monthly Sea-Level Anomaly
SLA = + 0.1426x – 284.91
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
Projection
The Seychelles is highly vulnerable to climate change.
It is concluded that it is likely (50–80%) that rainfall for
the December–February season and the annual rainfall
will increase, and it is unlikely to increase in the June–
August season (20–40%).
In addition, as indicated by the recent event in late
January, trends over the past years indicate that the
Seychelles is becoming subject to more erratic rainfall
patterns with short bursts of intense rain in hourly periods
rather than more extended periods of steady rainfall
over 2–3 days. This pattern may have contributed
to the recent flooding of January 27–28, 2013, which
included flooding in low-lying areas, landslides, and
contaminated runoff breaking through natural barriers
along the coast to the beaches and the coastal zone.
Coastal Inundation and Erosion
Seychelles’ coastal zones are under almost constant
pressure from both natural and man-made causes.
Anse Kerlan on Praslin is a case in which human interference
has completely destabilized the coastline.
Erosion-sensitive sites on Mahé and Praslin are being
lost at an average of between 1 and 3 meters per year
(Tsunami Disaster Task Force 2005 and the Seychelles’
Nation 1998). Noticeable changes in the wave energy
reaching the shores have occurred during the past decade.
Greater wave energy results in greater erosion
of the beaches. Climate change will exacerbate these
problems and lead to further destabilization of the
coastline.
Flooding in the low-lying areas is already becoming
more pronounced, especially with the occurrence of
storms that coincide with the spring tides. The recent
floods fit within this pattern and were further compounded
by the lack of appropriate drainage and highdensity
developments (as discussed in the section on
damage and losses in the environment sector).
Trends
Erosion along some of the coastlines has caused the
roots of existing coastal vegetation to be denuded, as
is the case at Anse Sevère on La Digue, and as a result,
breaks at certain spots and beach cliffs are formed.
Similar effects have been seen on Mahé at Anse aux
Pins beach as a result of the recent disaster.