Reference no: EM133190913 , Length: Word count: 3 Pages

Assignment Problem: Hurricane Related Coastal Erosion - Texas and New Jersey

Task 1: Texas Coastline - Hurricane Ike (2008) Aftermath

Think about the beach erosional features we have discussed in classroom presentations, as you look at the USGS images below.

Go to: the USGS Coastal Change Hazards: Hurricanes and Extreme Storms website

First look at Pre and Post-Storm photo comparisons for the Bolivar, Peninsula - there are four oblique aerial photographs provided.

Question 1) Based on your assessment of these images, approximately what percentage of the coastal community would you estimated was destroyed during the storm?

Now select: Pre and Post 3-D LIDAR Images Bolivar Peninsula from the menu.

Look at the two LIDAR images showing colored elevation maps pre and post-storm, as well as the third LIDAR map that shows net erosion and net deposition, including the before and after oblique aerial photographs.

Question 2) What is a LIDAR image?

Question 3) From these maps what is the maximum elevation of the Bolivar Peninsula before the storm (ignore the red peaks they are houses)?

Question 4) What is the maximum elevation of the Bolivar Peninsula after the storm?

Return to the main menus and select:

Pre- and Post-Storm Photo Comparisons for Galveston Island

Look at the Galveston Island pre-storm and post-storm oblique aerial photographs.

Question 5) Base on the data provided which of these two areas (Bolivar Peninsula or Galveston Island) do you think has the most damage?

Question 6) What are two reasons why one area had more damage than the other? (Be sure to look at the storm track and consider the difference between the "clean and dirty sides" of a hurricane.)

There are no LIDAR images for this area available, because Galveston (Barrier Island) is a bit older (2000-1500 yrs) that Bolivar Peninsula and Spit is younger (800 yrs). Galveston Island's elevations are around 4 m (15 feet) above sea level.

Now, look at the image from Jamaica Beach (Location 1) on Galveston Island. The current Open Beaches legislation states that public access (easement) to the beach includes the area between the mean sea level and the stable line of vegetation (LOV). This area should be free of any structure that would impede public access.

Question 7) After the storm, estimate how many houses would be "impeding" public access?

Question 8) Approximately what percent of the Jamaica Beach community is now on the public access portion of the beach as defined by the Open Beaches legislation described above?

Even before Hurricane Ike, 116 coastal homes were on a moratorium list from 2004-2006 beach erosion. The owners are offered $50,000 to remove their homes from the beach.

Task 2: LIDAR Images from Hurricane Sandy October 2012

Now let's look at a more recent storm on a more developed coastline.

Before and After LIDAR image comparisons:

Before and after air-photo comparisons

Choose one location along the coast of New Jersey (i.e., chose 1, 2, 3, 4, 5, 6, or 7)

9) Which site did you choose?

10) Referring to the "Elevation Difference Map", what was the maximum change in beach elevation for this beach after the storm?

11) Referring to the correlating air photos, what forms of coastal armament (groins, jetties, seawalls, riprap, etc.) are present at this location?

12) Do you think these structures were successful in protecting the beach and homes?