coastal regions and land loss n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Coastal Regions and Land Loss PowerPoint Presentation
Download Presentation
Coastal Regions and Land Loss

Loading in 2 Seconds...

play fullscreen
1 / 34

Coastal Regions and Land Loss - PowerPoint PPT Presentation


  • 93 Views
  • Uploaded on

Coastal Regions and Land Loss. Chapter 10. Morris Island Lighthouse, SC. Coastlines. Active vs. passive margins Population concentration Seven of 20 largest US cities on or near coastline 53% US population lives in coastal counties. Deep-water wave form (water depth > 0.5L).

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Coastal Regions and Land Loss' - cora


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
coastlines
Coastlines

Active vs. passive margins

Population concentration

  • Seven of 20 largest US cities on or near coastline
  • 53% US population lives in coastal counties
factors controlling waves

Factors controlling waves

Wind speed

Duration

Fetch

sea level changes
Sea level changes

Eustatic sea level rise caused by

  • Changes in amount of water in oceans
    • Short-term
  • Changes in shapes and volumes of oceans
    • Very long term
    • Related to sea floor spreading

Climate is major control

  • Thermal expansion or contraction of water
shoreline conditions
Shoreline conditions

Emergent

  • Earthquakes and uplift/downdrop
  • Glacial rebound
  • Area: New England

Submergent

  • Higher sea level
  • Irregular shorelines common
  • Area: Mid-Atlantic area – Chesapeake Bay (VA)
very short term changes
Very short-term changes

Storm surges

Changing tides

  • Extreme: Bay of Fundy, eastern Canada
    • 15 m tidal range twice daily
  • Normal daily changes (2 high, 2 low)
minimizing coastal hazards
Minimizing coastal hazards

Hard stabilization

Seawalls: concrete, large blocks

Cause more problems than they solve; they enhance beach erosion

slide28
Groins: built perpendicular to shoreline

Problem is the area down drift from groin is not fully replenished

Fix by beach nourishment

slide30
Breakwaters

Built to protect shoreline by intercepting waves

Jetties

Usually pairs of protrusions

Note beach modifications

soft beach stabilization
Soft (beach) Stabilization

Moving sand around, usually from offshore

Temporary solution due to dynamics

Must be repeated

managed retreat solution
Managed “retreat” solution

Prevent building

Relocate threatened buildings

miami beach fl 24 million cubic yards over 10 years
Miami Beach, FL24 million cubic yards over 10 years

Before beach nourishment

After beach nourishment

cape hatteras lighthouse
Cape Hatteras lighthouse

Built 500 m from water

Later moved 850 m inland