slide1
Download
Skip this Video
Download Presentation
The Kaikoura Coastline from the Hapuka to the Kahutara

Loading in 2 Seconds...

play fullscreen
1 / 15

The Kaikoura Coastline from the Hapuka to the Kahutara - PowerPoint PPT Presentation


  • 60 Views
  • Uploaded on

The Kaikoura Coastline from the Hapuka to the Kahutara. human actions that modify natural processes, and the outcomes. Focus. The focus of this section is on ‘how people modify a process’ that operates within your selected geographic environment NOT how people modify the environment.

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 ' The Kaikoura Coastline from the Hapuka to the Kahutara' - jacie


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
the kaikoura coastline from the hapuka to the kahutara
The Kaikoura Coastline from the Hapuka to the Kahutara
  • human actions that modify natural processes, and the outcomes.
focus
Focus

The focus of this section is on ‘how people modify a process’ that operates within your selected geographic environment NOT how people modify the environment.

Remember that a process maintains and/or modifies the environment so a change in the process will change the environment

modification of wave action
Modification of Wave Action

Wave Reflection

Sea Walls & End Effects

Groynes

Revetment walls (rip-rap)

wave reflection

Wave Reflection

When waves hit an object and the energy can not be absorbed or dissipated then it is reflected. This reflection causes increased turbulence as it mixes with the next incoming wave resulting in increased rates of erosion.

Content\MEDIA\V16202.MOV

scouring

Scouring

Increased erosion occurs at the base of sea walls, the wave undermines the structure and erodes at the base. This leads to slumping and collapsing behind the sea wall

end effects of structures

End Effects of structures

End effect is the term given to the erosion which can occur at the ends of sea walls due to longshore reflection of wave energy off the structure and loss of natural supply of material to nourish the beach.

As a general rule of thumb the end effects can extend up to 70% of the length of the structure i.e. a 45m structure has potential end effects of 30m either end of the structure

groynes
Groynes
  • Groynes are short walls built out from the shore to control the material moving along the shore.
  • If the groyne stops the sand from moving by longshore drift, the down drift side will no longer receive the material.
  • Content\MEDIA\V37163A.MOV
  • Content\MEDIA\V37161.MOV
steps at kaikoura
Steps at Kaikoura
  • The sea wall at Kaikoura has a set of protruding steps that act unintendedly as a groyne increasing rates of erosion
revetment walls
Revetment Walls
  • Rock revetment structures produce less end effects than vertical seawalls as they dissipate more energy due to the greater roughness of their surface. This also results in less overtopping by run-up
ad