Factors Effecting Costal Erosion Flashcards
What are the factors effecting costal erosion?
Waves
Sea depth
Costal configuration
Beach presence
Human activity
Lithology
How do waves effect costal erosion?
Wave steepness
Breaking point-eg at the foot of a cliff releases more energy
Fetch-longer the fetch, the greater the erosive power
How does sea depth effect coastal erosion?
Steeply-shelving sea bed, creates higher and steeper waves
How does the costal configuration effect coastal erosion?
Headlands attract wave energy through refraction
How does a beach presence effect costal erosion?
Beaches absorb wave energy
Provide protection against marine erosion
Steep beach=shingle
Flat beach=sand
How does human activity effect coastal erosion?
Sea defences reduce costal erosion in certain areas but increase costal erosion in other areas
Dredging removes protective materials EG sand and shingle leading to more erosion
How does lithology effect costal erosion?
Certain types of rock are more resistant to erosion
Permeability
More resistant-granite, chalk
Less resistant- clay
Differential erosion
Jointed jocks=limestone=less resistant characteristics of rocks
How are coastal management decisions made?
-cost benefit analysis
-environmental impact assessments
-feasibility studies
-risk assessment
-shoreline management plans
What is a cost benefit analysis?
Considers the social and economic aspects of a strategy, benefits of a scheme are divided by the costs of building and maintaining it
What are environmental impact assessments?
Assess the effects any strategy will have upon an area, very important along coastlines as attractive scenery and ecosystems are valuable tourist assets
What are feasibility studies?
They look at the technical merits of a particular scheme and site. Is the engineering planned suited to the local geology or coastal processes?
What is a risk assessment?
Involves taking decisions in the light of the likely recurrence interval and what is at risk. Insurance and legal claims will make this an important consideration in the future
What are shoreline management plans?
Try to decide upon the most appropriate scheme for each part of a littoral cell
