Coast GW1(What are waves and how are they generated+How do waves affect coastal areas)

Parts of a wave
Factors affecting wave energy
1. Wind Speed
  1. The faster the wind blows,the greater the wave energy is
2. Duration of wind
  1. The longer the wind blows,the larger the waves are
3. Fetch
  1. Fetch is the distance the wind travelled over seas to from waves.Greater the fetch,greater the wave energy is
Waves close to the coastlines
1. 1)Water is shallow.Waves interact with the seabed & change shape(depth=1/2 wave length)
2. 2)Waves continues to move in shallow water.Base of the wave slows down due to friction.Wave height increase wave length decrease.
3. 3)Base of wave stops;wave crest gets taller and topples over.This cause wave to break onto the coast,releasing energy
waves on beach
1. Swash
2. Backwash
Types of waves
1. Constructive
  1. Low gradient
  2. Small,low waves
  3. Low wave length,long wave height
  4. Wave frequency 6 to 8 per min
  5. Stronger swash than backwash
  6. Swells and spilling breakers
  7. Occurs on gentle coastal slope and sheltered coast
  8. Deposition process more prominent
2. Destructive
  1. High gradient
  2. Large,high waves
  3. High wave height,short wave length
  4. Wave frequency 10 to 14 per min
  5. Stronger backwash than swash
  6. Occur on steep coastal slope and open coast
  7. Erosion process more prominent
  8. Plunging & surging breakers

Resource summary

	Created by Hui Yuan almost 9 years ago