L1 ap 2013

Physical factors that create a variety of coastal environments

Competition for Coasts

Physical factors that create a variety of coastal environments

A. Land

1. Resistance of the rocks – GEOLOGY

Different rock types will create different landforms. E.g. Resistant Chalk and weaker limestone at Purbeck.

Physical factors that create a variety of coastal environments

A. Land2. Relief• Relief provides sheltered inlets and natural

harbours, e.g. Hong Kong Bay.

Physical factors that create a variety of coastal environments

A. Land2. Relief

Physical factors that create a variety of coastal environments

A. Land3. Presence or lack of beach Sand dunes, shingle beach or sand beach will all help to protect the land from erosion. E.g. Beesands, Devon.A lack of a beach will clearly increase rates of erosion.

Physical factors that create a variety of coastal environments

A. Land4. River sedimentsRivers carry vast quantities of sediment to the mouth. Once they meet the sea it is often deposited in the form of a delta. This adds to the coast and allows space for development as well as protection for the land. E.g. Nile Delta.

Physical factors that create a variety of coastal environments

B. Sea1. Coastal (marine) ecosystems• Mangrove swamps and coral reefs all help to

protect the land behind it. These ecosystems therefore protect the coast, especially from topical storms as they are found in tropics!

Physical factors that create a variety of coastal environments

B. Sea

2. Wave energy and direction• Waves can have huge impact on erosion and

therefore shaping the coast. The larger the fetch the more erosion. Compare Cornwall (……….. Fetch) to Suffolk (……….. Fetch) .

Physical factors that create a variety of coastal environments

B. Sea3. Size and type of wavesLarger waves clearly cause more erosion than smaller ones. Destructive waves have …………. Swash and a ……. backwash. These waves cause more damage than constructive waves ( ………… swash and ……….. backwash)

Physical factors that create a variety of coastal environments

B. Sea4. Local Currents and Long Shore Drift Long shore drift transports material along the coast. Clearly areas where LSD takes place means that there will be a small and temporary beach. Can increase the rate of erosion.

Physical factors that create a variety of coastal environments

B. Sea

Physical factors that create a variety of coastal environments

C. Weather and Climate

Physical factors that create a variety of coastal environments

C. Weather and Climate 1. Wind strength and directionOnshore winds will create more erosion than offshore ones. Also strengths can play an important role in the tropics, e.g. hurricanes.

Physical factors that create a variety of coastal environments

C. Weather and Climate2. Rainfall and temperatureTheses factors can influence weathering rates. E.g. slumping or biological weathering.

Physical factors that create a variety of coastal environments

C. Weather and Climate3. Storms surgesStorms surges result from hurricanes. They can damage coastal areas over long periods of time. The damage from hurricane Sandy was due to a storm surge.

Homework

• Find a photo of a coastal area and on it label at least 6 different factors that shape that area, e.g. Relief, high land that stops erosion from being too rapid