by Florence Duarte
"For healthy coasts, we must foster well planned and revitalized coastal communities that sustain coastal economies, are compatible with the natural environment, minimize the risks from natural hazards, and provide access to coastal resources for the public's use and enjoyment."
Introduction: Development of beachfront areas is controversial. On one side a growing human population demands the use of such areas for recreation and work. On the other, environmentalists and biologists hope to preserve these habitats. A compromise needs to be found that is responsible to both demands. Rational, sustainable usage of these areas is possible if people are willing to spend time and money in planning.
"It is important to realize that the problems we face in coastal areas are less related to the number of people than the way we choose to live. Certainly we have the technology to accommodate even larger numbers of people in even fragile areas like our coastlines, provided we are willing to change our patterns of land consumption, auto dependency and housing design."
In this paper I will discuss some of the issues communities have to consider for good planning of beach front developments. My purpose is to provide an overview of what is required in an environmental impact study to make a few recommendations for a prospective builder. The important categories to consider in the environmental impact study are: physical,biological and human activities.
I. Physical
Aspect to be Investigated: a. Developers must engage in
a thorough hydro-geological analysis of the coast. This includes identifying
the type of geological formation, underlying rocks, and the type and movement
patterns of the sand, waves, tides, and winds. It also includes identifying
and mapping sources of potable water (if any) and determining the depth
of the local water table. A good source of this type of information is
the
US Geological
Survey (USGS). This institution provides maps created with remote sensing
devices plus aerial and satellite images of any place on the planet. Other
institutions that also provide geographical data are listed in the
end of this paper.
b. Preparation for catastrophic
events, erosion control, and restoration of beaches need to be dealt with
by coastal communities. The response to the challenge varies from locality
to locality, with local, state and federal governments each having a part
in the final plan of action that is to be implemented. To help communities
analyze risk and prepare an action plan to deal with catastrophic hazards,
a natural hazard management model has been developed (Godschalk, 1989,
p.18) This model has four parts:
"Many of the coastal areas in the United
States are prone to natural
hazards such as storms, hurricanes, typhoons, tsunamis, and coastal
erosion and flooding. Losses of life and property from coastal storms are
generally affected by how well communities have planned for such hazards.
In short, the health of coastal economies and the lifestyles they afford
depend on well planned, sustainable development and healthy coastal resources."
Some factors that affect the natural rate of beach erosion are:
Sand source and sink: Sand
is brought to the shore from the continental shelf, rivers and eroding
cliffs, sand dunes, as well as from other beaches through the action of
long shore currents (Pilkey, 1996, p.24)
Sand-sinks include continental
shelf accumulations of sand that are in water at depths greater than 30
meters (100 feet) and sand that is carried into deep canyons. This sand
is below the "reach" of the waves and cannot be moved and returned to the
beach. In addition, sand blown inland is also lost from the beach. (Psuty,
1997)
Changes in relative sea level:
To
assess the scope of changes in sea level, scientists have developed methods
to interpret the geologic record left by pre-historic events. One of the
most useful markers for sea level studies has been the growth of coral
around islands such as Barbados, in the Caribbean Sea. The coral, Acropora
palmata, is restricted to a growth zone 2 meters from the sea surface.
By observing growth patterns of this coral, direct information can be learned
about sea level change over time. This approach is similar to the study
of tree rings to determine the age of a tree and the environmental factors
during the tree's life. Based on studies with coral, it is known that the
sea has changed drastically over the last 11,000 years.
Factors that influence sea level
include:
Sand size, density and shape: Beaches with smaller irregular low density sand particles tend to erode faster than beaches composed of large regular dense sand particles. They are more sensitive to wave action.
Sand-sharing systems of beaches, dunes and off-shore bars: Sand that is moved from a beach can usually be traced to offshore sand bars or to islands or dunes. The natural transfer of sand between beach environments does not represent loss. Only sand that is carried to depths greater than 15 feet is considered lost.
Effects of waves, currents, tides and wind: waves result from the movement of water caused by the rotation of the Earth and winds that blow over the surface of the water. Currents move bodies of water from one location to another, like a river flowing within the ocean. Tides are the daily cyclic movement of water toward and away from the coast caused by the gravitational forces of the sun and the moon.
Bathymetry
of the offshore sea bottom: is the term for the depth of the sea
at a given location. It affects the strength of waves as they approach
the beach. Deep waters near a coastline allow stronger waves.
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II. Biological Aspects to be Investigated: The biological community existing on the beach prior to its development is generally the least considered factor. In order to assure the proper maintenance of the local biota, prospective developers should follow these steps:
1. Survey: Identifying all (or most) living organisms and estimating their respective populations.
2. Research: Determining eating habits, shelter choices, reproductive and migratory behaviors.
3. Evaluation: Determining which organisms are more fragile, i.e., more sensitive to changes in the environment.
Houses should be located at intervals that allow the movement
of wildlife. Lawns are not advisable. Lawns are fragile ecosystems because
they are monocultures and require large input of energy, water and fertilizers.
Gardens should be created using only the local plants. A small varied
vegetable garden is acceptable provided can be irrigated with treated waste
water and fertilized with home-made compost. It provides needed fruits
and vegetables for humans.
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III. Impact
of Human Activities: Many coastal communities have already figured
out that it is not cost effective to degrade the environment in the long
run. However, the economic rewards in the short run have led
people to build without proper planning. Over building in hurricane prone
areas, over-taxed sewage systems, insufficient water supplies, over-fishing,
and destructive boating are consequences of poor planning. Responsible
development involves taking the natural system carefully into account.
Alternative energy sources such as solar and wind are viable and becoming
more cost effective. Knowledge and respect for the local plant and
animal life can reduce the burden on the environment.
IV. Building an Environmentally Friendly Beach House
Assuming a tropical deserted beach, building a single family home also involves careful planning even though the burden on the environment may seem insignificant. The first aspect to consider is the suitability of the terrain. The house should preferably be build on a rock foundation. Careful consideration of the legal restrictions on coastal building is imperative. Many laws project owners responsibilities well into the future.
Fresh water supply and sewage are also essential. A simple solar water desalinizer can be built economically provided there is ample sunshine and water use is moderate. Sewage can be processed in dry compost toilets to be used as fertilizer. It can also be processed in a anaerobic bio-gas generator to produce fuel gas.
Domestic appliances should be minimal but windmills and solar collectors can generate a good supply of electricity. Dishwashers may conserve water and soap, but air conditioning is a high consumption item. Hammocks on the porch are better remedy for heat. Computers and communication devices would be feasible.
Landscaping around the house should use only local plants and avoid interrupting wildlife corridors. Walls and fences should be minimal.
If individual homes were more self sufficient in providing for their own energy and waste disposal, they would reduce the burden on community resources.
