Topic 8 - Distinctive Landscapes Flashcards
what is a landscape
all of the visible features of an area of land. It can contain both natural features and man-made features.
what are the main 5 elements of making a landscape distinctive
- physical (mountains, valleys etc)
- Water (lakes, rivers etc)
- living (vegetation)
- Transority (weathering, the seasons)
- Human (Buildings, land use)
what are some physical charctersistics of lanscapes
- geology
- vegetation
- surface water
- Topography (height and shape of land)
what are some human characteristics of landscapes
- land use
- human activity
- accesebility
what is sedimentry rock
layers of rock combined together
what is igneous rock
made from volcanoes and cooled down lava
what is metamorphic rock
needs heat and pressure to form
what is freeze - thaw weathering
- caused by temperature changes like on mountains
- large temperature variation between day and night leads to freeze - thaw weathering
what is chemical weathering
- rain dissolves carbon dioxide in the air which forms weak carbonic acid, so the rainwater is naturally acidic
- the action of rainwater causes chemical weathering in rock
what is biological weathering
- caused by plants and animals
- tree roots can force there way into rocks which splits them appart
- smaller plants like mosses grow on the surface of the rock and slowly making it crumble
what is the physical process of shaping landscapes in rivers
- steep V - shaped valleys form in upland areas
- wide flat floodplains have developed over time in low land areas
- Most of UK have been affected by river to some extent
what is the physical process of shaping landscapes in glaciers
- glaciers no longer actively shape the Uk landscape
- large U - shaped valley, known as glacial thoughts, are carved out of the landscape in mountainous areas such as the lake district
what is the physical process of shaping landscapes in seas
- cliffs have been eroded and continue to retreat
- erosoinal landforms such as wave cut platforms, caves, arches and stacks are found along the coastline
- beaches are formed by the deposition of eroded sediment
what is the process of slumping
- formed by boulder clay, material is deposited by glacial periods, the soil or rock debris moves downhill along the concave or curved plane in a rotational manner
- description: saturated soil slumps along a curved surface
what is the process of sliding
- in areas of more resistant cliff material erosion is greatest when waves break at the base of the cliff
- creates a wave cut notch in the base of the cliff, the weight of the cliff above becomes too much to support and therefore landslides
- description: blocks of rock slide downhill
what is hydraulic action
waves crash against the coast, forcing air into cracks and breaking up the rock
what is attrition
pebbles picked up by the waves, bash into each other wearing them down into smaller round particles
what is abrasion
waves pick up rocks from the seabed and smash them against the coast, wearing it away
what is solution
rocks like limestone slowly dissolve in water
what is traction
large boulders and pebbles are rolled along the river bed
what is saltation
small stones, pebbles bounce along the river bed
what is suspension
fine material like clay and sediment is carried by the river
what is solution (transportation)
dissolved minerals are carried by the river
what is deposition
sediment is carried by rivers or wave is dropped and begins to build up new land
- at coast: occurs in low energy enviroments e.g beaches, bays, spits and sheltered areas
case study: jurassic rocks
- 250-200 million yars ago (Triassic period) rocks formed on a desert condition, rivers deposit thick layers of sediment
- 200 - 140 million years ago (Jurassic period) sea levels rise, flood deserts, thick layers of sandstone and limestone
- 140 - 65 million years ago (cretaceous period) sea levels dropped, new rocks and swamps and loogons
- 2.6 million years ago (quanternary period) erosion created hills and valleys, ice age
what is a spit
A stretch of beach at one end of a coastline caused by waves depositing material
what is a stack and a stump
the eroded remains of a sea stack, often looking like a lump of rock sticking up from its surroundings
how is a bay formed
The areas where the soft rock has eroded away, next to the headland
what is hard engineering
- works against natural processes e.g erosion to protect coastline
- more expensive and need to be maintained or rebuilt
what is the shoreline management plans
- local council in england and wales, required to produce shoreline management plan for strech of coastline
- do nothing, hold the line, retreat the line and advance the line
what is soft engineering
- works with nature to protect the coastline
- less expensive and easier to maintain, builing structures
what does hold the line mean
use hard or soft engineering to maintain sea deffences, expensive
what does retreat the line mean
create a gap in excising sea deffences to allow land to flood, cheapper option allows feature like sand dunes or salt marches to provde a barrier
what does advance the line mean
build new coastal deffences further out to sea, creating new land, most expensive involves hard engineering
what is rock armour
- hard engineering
- absorbs and deflects the impact of waves before they reach the beach
- £1000-3000 cheaper than sea wall
what is a groyne
- hard engineering
- traps sediment, restricts the transfer of sediment away from the beach through longshore drift
- relitavely cheap
what is a sea wall
- hard engineering
- prevents high tides and storm surges which causes flooding
- expensive
what is beach nourishment
- soft engineering
- sand spread over the beach where erosion is occuring to compensate shore erosion and restore the value of the beach
- relitavely cheap
what is offshore reef
- hard engineering
- old tryes and cement is placed in parrelel to the coast, this makes waves to break offshore
- expensive
what is managed retreat
- soft engineering
- a coastal management strategy that allows the shoreline to move inland, instead of attempting to hold the line with structural engineering
- cheaper
casestudy: Thames floods in 2014
- cause: Atlantic storms that lashed the Uk with heavy rain in winter and high water levels
impacts:
- social: 5000+ homes and buisnessses were flooded
- economic: many homes were badly damaged, the clear up cost from the flood was over £500 million
- enviromental: mass amounts of water flooding
- Jubilee river: was desgined to take overflow water from the river to reduce flooding
what are human actions that increase likelyhood of flooding
- deforestation: chopping down trees increase the rate at which water reaches the ground
- urbanisation: covering land with buildings and roads increases the rate at which the water flows over the ground
- river straightening: speeds the flow of water in the area, increases risk of flooding downstream
when is flooding most likely to occur
- ground is impermeable rock
- soil is saturated with water after weeks or months of rain
- the ground is frozen
- rainfall is so intense it cannot soak into the ground
what is a flood
when water overflows the banks and causes a huge amount of water
how to write casestudy: Thames river features
- geology: clay
- features: meanders and river terraces, shallow gradient means that lateral erosion takes place
- a meander is formed by the force of the water erodes and undercuts the river bank on the outside of the bend where water flow has most energy due to decreased friction.
why was the Thames barrier built
to prevent tidal water from reaching london
has the thames barrier been sucsessfull
no because it has been closed 50 and more times, they are building a new barrier which is high enough to cope with sea level in the 21st century
