Ch3 Distinctive landscapes

What are the landscape elements?

Physical - Mountains, Coastlines, rivers

Human - Buildings

Biological - Vegetation and wildlife

Variable - Weather, Smells

what is igneous rock?

Volcanic/ molten rock that has been cooled into solid rock

What is sedimentary rock?

Rock made from broken fragments of rock

what is metamorphic rock?

Rock that is folded and distorted by heat and pressure

What is soil made from?

From weathered rocks, water and organic materials

what is erosion?

The break down and transport of rocks

what are the types of erosion?

attrition

solution

abrasion

Hydraulic action

What is attrition?

Rocks bash together to become smaller

What is solution?

Chemical reaction that dissolves rock

what is abrasion?

Rocks hurled at a cliff to break pieces apart

what is hydraulic action?

Water enters cracks in the cliff and the air compresses the crack to expand

What is transportation?

A natural process by which eroded material is transported

What are the types of transportation?

Solution

Suspension

Saltation

Traction

What is solution?

Minerals dissolve in water and is carried along

What is suspension?

Sediment is carried in water

What is Saltation?

Pebbles that bounce along the sea / river

What is traction?

Boulders roll along a sea

What is mass movement?

Large movement of soil and rock debris down slopes in response to gravity pull

What are the stages of Freeze thaw weathering?

Stage 1 - water seeps into cracks in the rock

stage 2 - Water freezes and expands the rock apart

stage 3- With repeated freeze thaw cycles the rock breaks off

What is deposition?

when the sea loses energy and drops the sand and rocks it was carrying

How are bays and headlands formed?

1. Waves attack coastline

2. softer rock eroded and forms bay

3. more resistant rock is left jutting out

How are Coastal stacks formed?

1. Hydraulic action widens crack

2. abrasion forms a wave cut noch

3. further abrasion widens the cave

4. caves from both sides break through forming and arch

5. erosion below leads to arch collapsing forming a stack

6. further erosions forms stump

What are the hard engineering defences?

Groynes

Sea walls

What are groynes?

Wood barriers that prevent longshore drift so the beach can build up

what are sea walls?

concrete walls that break up the energy of the wave

pros and cons of groynes?

+ the beach is still accessible

- theres no deposition further down the coast so it erodes faster

pros and cons of sea walls?

+ long life span

+ protects flooding

- curves shape erodes beach deposits

what is beach nourishment?

beaches built up with sand so waves have to travel further before eroding cliffs

pros and cons of beach nourishment?

+ cheap

+ beach for tourists

- will need replacements if storms

how are coastal spits formed?

1. swash moves up the beach at an angle

2. backwash moves down the beach

3. Longshore drift transports material along the beach

4. deposition causes the beach to extend

5. change in prevailing wind direction forms hook

6. salt marsh forms

what is the upper course of the river?

near the source, river flows over steep gradient giving it a lot of energy to erode the riverbed to form valleys

how is a waterfall formed?

1. river flows over rocks

2. river erodes soft rock creating a step

3. hydraulic action and abrasion form a plunge pool underneath

4. hard rock undercut and collapses providing material for erosion

5. waterfall retreats leaving steep sided gorge

whats the middle course of a river?

Gradient gets gentler so water has less energy, the river erodes laterally making the river wider

what is the lower course of a river?

near the mouth, the river widens further and becomes flatter material transported is deposited

What are the 2 types of river management schemes?

Soft engineering

Hard engineering

Soft engineering river management schemes

afforestation - trees soak up rain water reducing flood risk

Managed flooding - naturally letting areas flood

Hard engineering river management schemes?

straightening channel- increases velocity to remove flood water

artificial leaves - heightens river so flood water is contained

deepening or widening river - increases capacity for a flood

How are levees formed?

when a river floods, fine slit is deposited on the valley floor. Closer to the river banks, the heavy materials build up to form natural levees