Florida’s beaches are a
well-known aspect of the state’s appeal to visitors and residents alike.
The state’s official website boasts of 1,100 miles of
beaches. Estimates of the
total length of Florida’s coastline vary according to the way that it is
measured. Florida’s tidal coastline is 2,276 statute miles. A
significant portion of the coast is marshy. Florida also has areas of
rocky coastline and coastline occupied by mangroves. Florida’s beaches
are essential to tourism, and growing numbers of permanent and seasonal
residents choose to live at or near the coast. Coastal erosion is a
cause for concern along many of Florida’s beaches.
Coastal erosion has both natural causes and causes
related to human activities. Gradual coastal erosion results naturally
from the very slow rise of sea-level. Severe coastal erosion can occur
over a very short period of time when the state is impacted by
hurricanes, tropical storms and other weather systems. Some coastal
erosion may be caused by poorly thought-out coastal development. However
Florida’s lengthy coastline necessitates the existence of many
navigation inlets and their construction and maintenance are an ongoing
source of coastal erosion.
Longshore currents move water in a direction parallel to
the shoreline. Sand is moved parallel to most beaches in Florida by
longshore drift and currents. Ideally the movement of sand functions
like a balanced budget. Sand is continually removed by longshore
currents in some areas but it is also continually replaced by sand
carried in by the same type of currents. Structures such as piers or sea
walls, jetties, and navigational inlets may interrupt the movement of
sand. Sand can become “trapped” in one place by these types of
structures. The currents will, of course, continue to flow, though
depleted of sand trapped elsewhere. With significant amounts of sand
trapped in the system, the continuing motion of currents (now deficient
in sand) results in erosion. In this way, human construction activities
that result in the unnatural trapping of sand have the potential to
result in significant coastal erosion.
The Florida Geological Survey’s Coastal Research Group
has a number of research efforts directed toward documenting coastal
erosion and also locating sources of sand for beach nourishment efforts.
That program is described at:
http://www.dep.state.fl.us/geology/programs/coastal/coastal.htm .
Maintenance of Florida’s sandy beaches is extremely important to the
environmental and economic health of the state. The Bureau of Beaches
and Coastal Systems has a variety of programs that aim to maintain and
protect Florida’s coast. Coastal erosion and efforts to combat it, as
well as permitting that is aimed at preventing such erosion are
described in more detail at the website:
http://www.dep.state.fl.us/beaches/
Click on any picture to
enlarge.