Focus Question: How does coastal change impact real estate?

 

Feel free to email the instructor (dpalmer@kent.edu) with any
comments about the format and ease of use of these online notes.

Coastlines and Beaches:  The problem of Erosion

1.  “Approximately 25 percent of homes and other structures within 500 feet
of the U.S. coastline and the shorelines of the Great Lakes will fall victim to the effects
of erosion within the next 60 years, according to a study released recently by the
Federal Emergency Management Agency (FEMA, 2000)”.

2.  “Sixty percent of nationwide losses will occur along the Atlantic and Gulf of Mexico
coastlines (FEMA, 2000), with costs to U.S. homeowners averaging more than a half
billion dollars per year (FEMA, 2000)”.

3.  Coastal Erosion is driven by storm activity (especially hurricanes) and by longshore
current activity.  Property owners try to slow or stop erosion, but this usually doesn’t work.
 Examples:  California mudslides
 Gulf of Mexico Hurricanes
 Longshore transport, Atlantic Coast

4.  Shaping a Secondary Coast -  Sediment Transport
Longshore drift = movement of sand along a beach by wave action
Graphic: review Figures 10-25 through 10-28 and figure 15-11 in the text.

5.  Shoreline Stabilization
People have attempted to stabilize coasts and beaches using:
Groins - walls perpendicular to the shore
Seawalls - "armoring" the shore
Sand replenishment - importing sand
Graphic: Figure 10-28

6.  Other Shore Stabilization Strategies
Riprap - irregular rocky structures that dissipate wave energy
Wind Fences - reduce beach erosion by the wind

7.  Along-Shore Drift - An Example
Sand accumulates "upstream" of the barrier
Sand is depleted and erosion is accelerated "downstream" of the barrier

8.  Coastal Erosion
Coastal erosion varies from place to place, depending on
- hardness and resistance of rock
- wave action
- local range of tides

9.  FEMA  Federal Emergency Management Agency,
 independent federal agency, reports directly to the President since 1979
has 27 other federal partner agencies, and is also partnered with the American Red Cross

10.  FEMA includes the Federal Insurance Administration,
the National Fire Prevention and Control Administration,
the National Weather Service Community Preparedness Program,
the Federal Preparedness Agency of the General Services Administration
and the Federal Disaster Assistance Administration activities from HUD.

11.  Barrier Islands, created by long shore transport, are sandy, dynamic environments
 subject to severe erosion during storms
 in the U.S., traditionally highly prized real estate
 famous barrier islands include
  Atlantic City, NJ
  Ocean City, MD
  Miami Beach FL
  Palm Beach, FL
  Galveston, TX

12.  FEMA regulations, rebuilding after storm destruction
a. structure must be 2 feet higher than the water level that destroyed it
b. no new construction on barrier islands

13.  Choosing a coastal property
a. which direction is the longshore transport?
b. Is your section of beach gaining or losing?
c. Where is the dunefield?
d. What changes are being made to the beach just upcurrent and downcurrent from you?
e. Is there a recent history of erosion/storm damage?
f. Is the house on a cliff?  What is the condition of the foot of the cliff?
g. Do you know where to get coastal erosion maps or flood maps?

Next lecture:  Coastlines and Pollution 
Focus Question:  What are the sources of pollution in the ocean?