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Science and Technology
With a focus on nature
Beyond increasing the risks of natural disasters to
small island states, the rise in mean sea level (MSL)
is among the main causes
of erosion
in many coastal areas
across the planet.
This
harmful
process affects
the environmental quality of
many
beaches on the western and
southern coasts of the
United
States, Jamaica,
Mexico,
the
Dominican Republic,
Spain,
South America and the
Black
Sea, to cite a few
examples,
where prejudicial natural
conditions have
combined with the
inappropriate actions of
human beings.
As
reflected in
one of the chapters of
the book,
Impact of Climate
Change and Adaptative
Measures in
Cuba, presented
recently in
Havana and including the work of specialists from 30
institutions and agencies,
worldwide
MSL grew
at an average rate
of 3.1mm
between 1993 and 2003,
while an increase of 22 to
85
centimeters
by 2100 is predicted.
This
change
is attributed to thermal
expansion of the oceans
and the loss
of the
ice in glaciers and
polar icecaps. It is worth
mentioning that the
increase will not
occur
uniformly across the world’s different geographical
areas, as
there are other contributing factors, including
vertical land movement (VLM).
RESTORING SAND DUNES
Studies conducted
as part of the
Macroproject on
Coastal Hazards and
Vulnerability
for the years
2050 and
2100, by researchers
from the
Institute of
Oceanography
at the Ministry of Science,
Technology and Environment,
in collaboration
with various other institutions,
has confirmed that the erosion
of Cuban
beaches is widespread,
with a
coastal erosion rate
estimated at
1.2
meters
per year.
Doctor of
Geographical Sciences,
José Luis
Juanes, head of the
Coastal Processes
Department at the institute, explained to Granma
that in some parts of the country
there are reports of an erosion rate of over 2.5
meters per year, similar to
that recorded for
the rest of the
Caribbean region.
He
indicated that the cause
is in large part the rising
sea levels surrounding Cuba
(between 1996 and
2009 the average
rate rose to
1.43mm
per year in the archipelago),
combined with
extreme
erosive events caused by
the onslaught of
weather phenomenon and a
deficit
in terms of sources for the production of sand.
Add
to this the negative actions of human beings in the
past, specifically construction works on top of
natural sand dunes, the extraction of sand, as well
as the incorrect design and location of breakwaters
and inner harbors.
Dr.
Juanes explained that as part of the studies
conducted, the national tally of beaches was
updated, with the number rising to 424. Of 257
technically evaluated, 86% showed signs of erosion.
The
most significant cases
were observed
on Guanimar,
Majana,
Cajío, Mayabeque
Caimito, La Pepilla,
Tasajera
and
Rosario
beaches, located in
the provinces of
Artemisa
and Mayabeque,
which have suffered
from ruthless human
activity for many years,
and were affected by
severe
surf generated
by
hurricanes Gustav
and Ike
in 2008, leaving beaches
virtually devoid
of sand.
Among the main
evidence
of this process is the existence
of numerous fallen and
damaged trees in the sea.
Similarly,
it is evident that
the passage of
powerful hurricanes causes
coastal flooding which
overran sand dunes in
various parts of the country.
This leads to
the transfer of
sand towards
inner
lagoons, causing
significant structural
changes in the outline of
the coast.
According to Dr. Juanes,
this may reflect
a specific manifestation
of the effect of
sea level
rise, an issue which
remains under
investigation.
The
knowledge
accumulated through these studies
has allowed for work on the
design of
forecasting models
to assess the response
of sandy
coasts to rising
MSL, as
well as the adoption
of measures to
ensure better protection
of our beaches and
erosion control.
It
is
worth mentioning that
sand has been
artificially
supplied in
Varadero
since
1987,
in
order to
rebuild and maintain
the
required quality levels of
the beach for bathers.
Constructions on top of natural
dunes have been demolished and
the dunes gradually restored.
One
of the
ongoing projects
related
to the aforementioned is that
aimed at the
functional rehabilitation
of the sand dunes
in
Playas
del
Este,
specifically in the area of about
300
meters
in front of the
Tropicoco
Hotel in Santa
María del
Mar. Over ten thousand cubic meters of sand has
been deposited in the area, with
beach
grasses and boniato having been planted in
order to stabilize and
prevent the loss of the
deposited sand.
Elevated wooden walkways
have also been built to avoid trampling of
vegetation on top of the dunes, and provide access
to the beach.
This
work has
been extended up to the Itabo
river mouth, at the end of the Boca
Ciega beach.
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