Geography - Coasts

A coastal area is an area located near a coastline which border the sea. It it where the land interacts with the sea. Coastal landscapes differ because of rock type, management, erosion and weathering. 

Uses of coastal areas include:

• tourism
• ecosystems
• fishing
• transport
• trading

Threats towards coastal areas include:

• rising sea levels
• pollution
• erosion
• tropical storms

Wave crest - highest point of wave, formed when water risis

Trough - lowest point of wave, formed when water falls

Wave length - distance between two successive crests/troughs

Wave height - distance between crest and trough

Swash - waves breaking and travelling up beach carrying load in prevailing wind direction

Backwash - waves returning to sea with load  taking the shortest possible route (gravity)

Constructive

• They are created in calm weather and are less powerful than destructive waves
  
• Have a stronger swash than backwash, so they deposit material and build up beach
• Less frequent than destructive waves (6-9 per minute)
• Low with long wavelength - they roll onto the beach

Destructive Waves

• They are created from big, strong waves when the wind is powerful and has been blowing for a long time
• They occur when wave energy is high and the wave has travelled over a long fetch
• They have a stronger backwash than swash, so they erode material and transport it away from beach 
• They are more frequent that constructive wabs, and break 10-15 per minute
• They are tall with a short wavelength and have a greater distance to fall when they break

Waves are formed by friction between the wind and sea. The type and size of waves are determined by three factors:

• Strength of wind

The stronger the wind, the bigger the waves

• Wind duration

The shorter time the wind blows for, the small the waves

• Fetch (distance wind travels)

The longer the fetch. the bigger the waves