P1 Flashcards
What is Commercial Farming
growing crops or raising livestock, largely for sale to others
What is subsistence farming
farming in which only enough food to feed one’s family is produced
What is an Aquifer
an underground water reservoir
What is accessibility
how easy it is to enter and exit a certain place
What is desertification
The process by which fertile land becomes desert, typically as a result of drought, deforestation or inappropriate agriculture
What is Overgrazing
Land becoming unsuitable as a result of animals eating too many plants in one area
What is overcultivation
Cultivation which, given environmental resources, is not sustainable in the long term and is evidenced by declining yields, soil exhaustion and soil erosion.
Drought
a long period of dry weather
describe what being ecologicallyfragile means
Areas where even the slightest change in temperature can have devastating effects
Where is the Thar desert
It stretches across north-west India and into Pakistan
Types of enery which can be created in the Thar desert
- Coal
- Oil
- Wind
- Solar
What are the main challanges for development in the Thar desert
- Extreme temperatures
- Water supply
- Inaccessibility
Why are there water shortages in the Thar desert (3)
- There is a high demand for it as the farming industry has developed.
- The desert has low annual rainfall a
- High temperatures with strong winds, which cause high rates of evaporation
What are the challanges that come with extreme temperatures
- Health challanges for people working outside (farmers, mine workers, tour guides)
- Tourism is limited and is only in the coolest months
- Low rainfall and high rates of evaporation
- Dehydration of animals and plants
What are the water sources of the Thar desert
- Most drinking water for is stored in ponds
- The Indira Gandhi Canal
What is the Indira Gandhi Canal
Longest canal in India. It is the main source of irrigation in the Thar dessert. It has transformed the desert and has turned a lot of the sand into productive farmland
Why is the Thar dessert inaccessible
- Extreme weather
- Very limited road network
The high temperatures cause for the tarmac to melt and strong winds often blow sand over roads - Only accessible by camel
What are the two main factors which effect the development of coastal erosion landforms
- Geological structure
- Rock type
How are headlands and bays formed
They form when rocks of different strength are exposed. The weaker bands of clay will erode more rapidly than neighbouring bands of more resistant materials such as sanstone and limestone. Over time the eroded clay form bays, where sediment is deposited to form beaches. The more resitant rocks stick out into the sea to form headlands
How are Cliffs and wave-cut notches created
When waves break against a cliff, it will slowly wear away the cliff to form a wave-cut notch. Over a LONG period of time it will get deeper and deeper till the overlying cliff can no longer support its own weight and it collapses
How are wave-cut platforms created
After a wave-cut notch colapses, the cliff will gradually retreat and in its place will be a gently sloping rocky platform called a wave-cut platform.
What is Hydraulic Power
The power of the waves smashing into a cliff. This traps air into holes and causes cracks in the rock eventually breaking them apart
What is Abrasion
when small rocks are carried by the sea and thrown at a cliff causing them to wear away in a sandpapering effect
What is Attrition
when rock fragments carried by the sea knock against one another causing them to get smaller and more rounded and eventually into pebbles
How are caves created
Lines of weakness such as cracks in a cliff are erroded by hydraulic action and abrasion to form a cave
How is an arch formed
Over time erosion may lead to two back-to-back caves to break through and create an arch
How is a stack created
Gradually an arc is enlarged by erossion to the point where it collapses to form a pillar called a stack
What is freeze-thaw
When water gets trapped in a rock and freezes causing for the rock to crack/break as the water has expanded
How is a stump created
A stack is erroded and collapses which leaves a stump
What is a beach
A deposit of sand and shingle (pebbles) at the coast
How are sand dunes created
Sand deposited on the beach has been blown inland by onshore winds to form dunes
Explain the development of sand dunes
- Embryo dunes form around deposited ostacles such as peices of wood or rocks
- These develop and become stabilsed by vegetation to form fore dunes and tall yellow dunes
- Over time, rotting vegetation adds organic matter to the sand, making it more fertile meaning more planrs colonise these dunes
- Wind can form depressions in the sand called dune slacks, in which ponds may form
What is a Spit
A long narrow finger of sand or shingle jutting out into the sea from the land
How are spits formed
They are formed when there is significant longshore drift.
1. Sediment is deposited out to sea
2. As it builds up it starts to form an extension of the land
3. This process continues and the spit gradually grows further out into the sea
4. Strong winds or tidal currents can cause the end of the spit to become curved to form a featured called a recurved end
5. There may be many recurved ends marking previous positions of the spit
What is a bar
A bar when a spit grows right across a bay trapping a freshwater lake or lagoon behind it
What does the Lyme Regis Enviromental Improvement Scheme do?
It provides for long term protection, reducing landslips
What are the phases to the Lyme Regis Enviromental Improvement Scheme
Phase 1 → Emergecy stabilisation of cliffs
- £1.4 million
- Installing large nails to hold the cliff together
- Improve drainage
Phase 2 → Improvement to seat front
- £22 million
- New sea walls
- Creation of sand & shingle beach
- Shingle from English channel, sand from France
Phase 3 → wasn’t undertaken
Phase 4 → more phase 2
- £19.5 million
- New seawall infront of existing sea wall for extra protection
- Nailing, piling, drainage, stabilising the cliff for homes.
3 positive outcomes to the Lyme Regis Envorimental Improvement Scheme
- New beaches → increasing tourism
- New defences → work better against harsh weather
- Harbour → better protected for fishermen
Negative outcomes to the Lyme Regis Enviromental Improvement Scheme
- New defences spoilt landscape
- Stabilising cliffs prevents landslips which could reveal important fossils
- Higher congestion due to more tourism could lead to conflict with locals
What types of engineering were used in the Lyme Regis Enviromental Improvement Scheme
soft & hard
How does a river flood occur
River floods usually occur after a long period of rainfall often during the winter. The volume of the water steadily increases causing river levels to rise. Eventually going over it’s banks and causing a flood
How do flash floods occur
Sundown floods which occur after torrential storms
What are physical factors of flooding
- Precipitation
- Geology (type of rock)
- Steep slopes
What are the Human factors to floods
- Urbanisation (building on floodplains)
- Deforestation
- Agriculture
What are soft engineering methods of flood management
- Floodplains
- River restoration
- Wetlands