Environment and development in coastal regions and in small islands |
alternative PDF version
Wise practices for coping with beach erosion:
Dominica
Forestry, Wildlife and Parks
Division, Dominica
University
of Puerto Rico, Sea Grant College Program
Caribbean Development Bank
UNESCO
Environment and Development in Coastal Regions and in Small Islands
FORCES
TO BE RECKONED WITH
Beaches are continuously changing – from day to day, month to month and year to year – as the natural forces of wind and water meet the land. These changes, which have been taking place for millions of years, are linked to variations in wind, waves, currents and sea level.
But it is not just natural forces that change the beach. Humans have a big role to play in this process as well, through mining stones, gravel and sand from the beaches, polluting and damaging coral reefs, and constructing buildings and walls too close to the sea.
Changes in the beaches affect everyone. The coast is a place we are all attracted to for recreation, sports and simple enjoyment. This constantly changing and hazard-prone coastal environment is also where the greatest financial investment is concentrated, as roads, airports, buildings and tourism properties continue to be constructed on the only flat area in Dominica - the land behind the beach.
Natural
forces
Since
1995, the Atlantic Basin (including the Atlantic Ocean, the Caribbean Sea, and
the Gulf of Mexico) has entered a more active hurricane cycle, which may
continue for more than 20 years. |
Hurricane frequency between 1990 and 1999 in the Atlantic Basin |
Source: Gray et al. http://typhoon.atmos.colostate.edu/forecasts/1999/nov99/ |
In
the Atlantic Basin the number of really severe hurricanes (categories 3, 4 and
5) increased from one per year (1990 –1994) to four per year (1995 – 1999).
Human forces |
A baby leatherback |
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WHAT’S
HAPPENING WITH DOMINICA'S
BEACHES?
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In order to manage these changes, Dominica’s beaches have been monitored since 1987 by the Forestry, Wildlife and Parks Division who measure the beach slope and width regularly at numerous sites around the island. |
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Location
of monitored beaches in Dominica
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SAND IN, SAND OUT
Several hurricanes have hit Dominica in recent decades, and beach sand and stones are lost during each event. Following the hurricane event, the beaches recover to some extent, but not to pre-hurricane levels.
BEACH
PROFILE |
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Toucarie Bay in 1987 | |
In 2000,
after three |
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HURRICANES WREAK HAVOC
On the southwestern corner of Dominica, before Hurricane David in 1979, there used to be a tree-lined ridge connecting the small islet of Scotts Head to the mainland. Now, after several hurricanes, all that remains is a low stone bank which is easily breached by small storms.
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Coastal highway
under the Tarou Cliffs, 2000.The
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Waves
building at |
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HERE
TODAY,
GONE TOMORROW
The table shows generalised rates of change at the measured beaches in Dominica. During the period 1988-1999, nearly all the beaches showed erosion, a result, at least in part, of the impact of several severe hurricanes since 1989. However, most of the beaches in Dominica show erosion along one part of the beach and accretion (or build-up) at adjacent sections, thus these figures must be treated as average trends.
Beach change rates in Dominica 1987 - 2000 (metres per year) |
A
negative rate of change (–) indicates erosion and retreat of the shoreline, a
positive rate of |
A once popular picnic |
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WISE
PRACTICES FOR A HEALTHY BEACH
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The
state of the beach affects everyone’s lives. There are no simple or universal
solutions to shoreline erosion, since there are often several factors, both
human and natural, contributing to the problem at a particular beach. Each beach
behaves differently, so it is advisable to find out as much information as
possible about a particular beach before taking any corrective action. It is
necessary to consult the Physical Planning and Development Division before undertaking any
action at a beach. Some
forces of change, such as hurricanes and winter swells are natural, and there is
little we can do to stop them, yet there are ways we can help to slow down the
rate of erosion:
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Ensuring new |
Buildings close to the beach
are vulnerable to erosion |
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Buildings at a ‘safe’
distance from the beach are less |
Hard
engineering structures
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A waterfront
hotel Rebuilding
on the |
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For
more information on shoreline Forestry,Wildlife and Parks Division Physical Planning Division |
For
more information on shoreline Coping
with Beach Erosion
This
booklet is a result of |
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Illustrations: Barbara Navi – Photographs: Gillian Cambers, Arlington James – Design: Eric Loddé