Please enable JavaScript.

Coggle requires JavaScript to display documents.

a level geography detailed notes aqa - Coggle Diagram

- - - - inputs - material/matter or energy added to a system. outputs - material/matter or energy subtracted from a system. stores - matter/material or energy sequestered. transfers/flows - processes that link inputs, outputs and stores.
      - stores - soil water (utalised by plants) mid term - ground water ( stored in pore spaces of rock) longterm - river channel (water stored in river)short term - interception(water intercepted by vegitation) short term - surface storage (puddles,ponds,lakes) variable
        
        aquifiers -shallow ground water aquifiers 200years - deeper fossil aquifiers 10,000years - glaciers 20-100yers possibly feeding lakes for 50 -100years - seasonal snow cover and rivers 2-6months - soil water 1-2months.
        
        water can be stored in: hydrosphere (liquid) lithosphere (crust and upper mantle) cryoshpere (frozen) atmosphere (vapour)
        
        soil water budget an annual balance between inputs and outputs and impacts on soil water storage aailability the budget. maximum storage is dependent on type, depth, permeability of the soil and bedrock type. surplus of water in winter months after recharge of water in autum, this water is used in spring and summer when temperatures are hotter and evapotranspiration is at its highest. when evapotranspiration is higher than precipitation the stores are depleting and in deficit.
        
        water balance precipitation=total runoff + evapotranspiration +/- change in storage this equation can help explain droughts or floods changes to physical factors ands seasonal variation.
      - flows - infiltration ( water seaps into the soil) - infiltration capacity determains how quickly infiltration occurs) - grass and tree roots create passeges for water increacing the infiltration capacity- precipitation falling at a greater rate than infiltration capacitty causes overland flow which can lead to floods. -- percolation - water moves from the ground into porous rocks -- through flow water moves through the soil into strreams or rivers dependant on the type of soil - clay soil has a high feild capacity and small pore spaces which means a slower rate however sand soil drains quickly and has a low field capacity and larger pore space. natural channels for animals such as worms = fast rate.-- surface runoff - happens when infiltration capacity is already reached or impermeable surfaces
      - outputs - evapotranspiration - plants respire by photosynthesis and relase water which is evaporated - stream flow - all water enters drainage basin and leaves through the atmosphere or strreams which drain the basin - these may flow as tributaries wich is a fresh water stream that feeds into larger stream or river.
      - inputs precipitation convectional - heating by the sun makes warm air rise it condenses at higher altitudes and falls as rain fall. relief rainfall - warm air forced upwards by a barrier such as mountains causing condensing at higher altitudes bring rain. frontal rainfall - warm air rises over cool air which is less dense as warm air is lighter it condenses at the higher altitude and brings rain.
  - - - transfers photosynthesis - living organisms convert carbon dioxide from the atmosphere and water from the soil into glucose using light energy removing co2 from the atmosphere. respiration - opposite of photosynthesis. combustion - burning fossil fuels. decoposition - living organisms die and are broken down by decomposers which respire returning co2 to the atmosphere and soil. diffusion - the ocean absorbs co2 from the atmosphere however this harms aquatic life (coral bleaching). weathering and erosion - rock particles are broken down and used to make shells by marine life. burial and compaction - sea shell fragments are compacted overtime to form limestone and fossil fuels. Carbon Serquestration - transfer of carbon from the atmosphere can be both natural and artificial.
      - stores - lithosphere marine sedimentery rocks - longterm - fossil fuel deposits - long term but currently dynamic - soilorganic matter - mid term hydrosphere oceans - dynamic fossil fuel deposits atmosphere - dynamic biosphere terrestrial plants - midterm but very dynamic
        
        the lithosphere is the main store of carbon with global stores unevenly distributed. eg terrestrial plant storage is foccused in the tropics ( rainforests)
        
        carbon budget - balance between inputs and outputs in the carbon cycle. carbon sink - a store that absorbs more carbon than it emits - carbon source - a store that emits more carbon than it absorbs.
      - regional climates - high rates of photosynthesis and respiration leads to greater humidity, cloud cover and precipitation. deforestation reduces photosynthesis and respiration reducing humidity and cloud cover decreasing precipitaion
      - positive feedback loops - 1) ice reflects radiation froom the sun reducing surface warming as sea temperatures rise and ice melts the warming effect is amplified and less ice to reflect radiation so the sea temperature level rises causing further melting and breaking dynamic equalibrium. 2) anthropogenic cobustion of fossil fuels releases greenhouse gases into the atmosphere trapping solar radiation from the sun this increases the global temperature causing permafrost to melt inside the permafrost methane is created from decaying organisms and oxygen deprevation methane is a greenhouse gas that is 28x as potent for the atmosphere but only lasts decades compared to centeries this amplifys the enhanced greenhouse effect heating up the earth even more breaking dynamic equalibrium. negative feedback - increased photosynthesis by plants due to rising global temperatures allows vegittion to grow in new areas allowing more carbon sequestration reducing global temperatures bringin it back into dynamic equalibrium.
    - - natural - wildfires co2 released through burning transferring from biosphere to atmosphere - volcanic activity released in eruptions as co2 gas. human impacts fossil fuel use combustion co2 transferred to the atmosphere from long term carbon sink - deforistation used to clear land for cattle farming and housing by slash and burn interupts forest carbon cycle- farming practices arable farming relaeses co2 as animals respire. ploughing releases co2 stored in soil. farming machnery releases co2. -
- - - - inputs - waves, tides, sun pollution sea defences. outputs - ocean currents sediment evaporation. transfers and flows - mass movement, weathering, longshore drift erosion. stores/sinks - beaches, sand dunes, spits, stumps, salt marshes tidal flats offshore dars and bays.
        
        erosion - corrosion/solution - mildly acidic seawater causes alkaline rockes eg limestone to dissolve. hydralic action - air is forced into cracks as waves crush into cliffs face high pressure makes crackes force abart and widen. attrition - rocks and pebbles to hit against each other becoming round and smaller . corrasion - sand and pebbles are picked up by the sea from offshore sediments sink and hurled against the cliffs. abrasion - sediment moved along the shoreline causing it to be worn down over time. wave quarrying - similar to hydralic action but more pressure directly pullls rock away from cliffs leaves open to oother erosion 30tonnes per m^2.
        
        factors effecting erosion - waves are the main factor with winter destructive waves - beaches absorb wave energy in front of the cliff which reduces erosion. - anthropogenic coastal management such as groynes trap and starve beaches. - subarial processes such as weathering and mass movement weaken cliffs - rock types and rock faults also play a role ( rock lithology)
        
        longshore drift - waves hit the beach at an angle determined by the direction of the prevailing wind - the waves push sediment in this direction in the swash - the wave then carries the sediment away from the beach backwash - moving sediment along the beach over time.
        
        weathering - mechanical/physical weathering is the breaking down of rocks over time leading to transfer of inputs into sediment cells . freeze thaw/frost shattering water enters cracks in rocks freezes and expands developing cracks. - salt crystallisation seawater evaporates leaving behind salt, salt crystals grow forces craks to widen salt also corrodes ferrous rock. - wetting and drying rocks such as clay expand when wet and then contract when dru tese cycles cause the rock to break up. chemical weathering carbonation rainwater absorbs co2 to crate weak carbonic acid (acid rain) reacts with limestone to from calcium bicarbonate which easily dissolves. - oxidation minerals exposed to air will oxidise increasing volume causing rock to crack. - solution when rock minerals such as salt dissolve. biological weathering - plant roots growing into cracks of rocks exerting pressure splitting rock. - birds puffins dig burrows into cliffs weakening them. - rock boring clams secrete chemicals that dissolve rocks. - seaweed acids kelp contains sulphuric acid dissolves rock minerals. - decaying vegitation water flows through decaying plants and becomes acidic.
        
        temperature and climate can influence prominence of weathering - in colder climates mechanical wethering is more common, where as in warmer climates chemical weathering is more commen
        
        mass movement the movement of material down a slope under the influence of gravity. - soil creep soil particles move down the hill due to wetting and freezing This forms shallow terracettes. - solifluction occurs in periglacial environments where top layer thaws in summer and surface layer flows over frozen layer. - mudflow increase in water content of soil reduces friction leading to earth and mud flowing over underlying bedrock or clay, these represent a serious threat to life very fast moving. - rockfall occurs on slopped cliffs when exposed to mechanical weathering mostly occurs on vertical cliff faces leads to scree (loose pieces of rock) building up at base of slope (input). - landslide heavy rainfall reduces friction in cliffs leading to landslides, occurs when blocks of intact rock fall very quickly down cliff faces. - landslip / slump slope is curved and land collapses under its own weight creates terraced appearance. - runoff water may erode cliff face or pick up sediment, increases pollution in coastal areas.
        
        transportation -saltation/bed load - transport of rolling/ saltating along the bed surface - suspension - lighter sediment floats and disperses away- traction - rocks are rolled along the river bottom by waves- solution - water disolves certain sediments
        
        energy - the power and driving force behind the flows and transfers - wind - gravitational - flowing water
        
        wave formation wind moves across the surface of the water causing frictional drag - crating small waves leadijng to orbital motion of water articles - seabed becomes shallower orbit of particles becomes eliptical leading to horizontal movement of waves. - wave height increases but length and velocity decrease. - water backs up behind the wave until it collapse.
        
        factors affecting wave energy - strength of wind - duration of wind - size of fetch
        
        constructive waves - formed by weather systems that operate in open oceans long wave lengths - 6-9 per minute low waves which surge up the beach strong swash weak backwash occurs on gently slopped beaches. destructive waves - localised storm events with strongr winds operating closer to the coast - short wave lengths - 11- 16 per minute high waves which plunge onto the beach weak swash strong back wash occurs on steeply sloped beaches.
        
        negative feedback loops - nulifying effect of changes which occur in a system. eg: a storm erodes a beach (out of dynamic equalibrium) as larger inputs than out puts of sediment. when destructive waves form storm loses energy, excess sediment is deposited as an offshore bar. Bar disipates wave energy and protects beach from further erosion. over time bar is eroded insted of beach. when the bar goes normal conditions ensue and the system goes back to dynamic equalibrium.
        
        wave refraction - waves turn and lose enrgy around a headland on uneven coastlines wave energy is focussed on headlands - erosional features - energy dissipated in bays - formation of features ( lower energy environments eg beaches)
        
        sedimentary eg limestone erodes very fast 0.5-10 cm per year due to weak faults. metamorphic eg slate, schist and marble erodes slowly at 0.1 - 0.3 cm per year due to crystals orientated in the same direction. rock type igneas eg granit or basalt erodes very slow 0.1 cm per year due to interlocking crystals
        
        sediment sources rivers majority of sediment, deposited in esturies. - cliff erosion unconsolidated cliffs erode easily more erosion in winter. - wind coastal energy source wind transports sediment from sand dunes. - glaciers can flow directly into the ocean depositing sediment when the calve - offshore sediment transferred when waves, tides and currents, erode offshore sediment sinks this builds up the beach. - longshore drift sediment moved along the beach due to prevaling winds.
    - - littoral zone - an area of land between the cliffs or dunes and the offshore area that is beyond the influence of the waves. changes; short term - tides storm surges - long term - sea level anthroprogenic influence
    - - low energy coastlines - less powerfull waves - shelterd areas - constructive waves prevail - sandy areas - lanforms of deposition - deposition exceeds the rates of erosion. high energy costlines - more powerful waves occur in areas of large fetch - rocky headland and landformes - frequent destructive waves eroding cliffs - rate of erosion exceeds the rate of deposition.
        
        wave refraction - waves turn and lose enrgy around a headland on uneven coastlines wave energy is focussed on headlands - erosional features - energy dissipated in bays - formation of features ( lower energy environments eg beaches)
        
        deposition - occurs when sediment becomes too heavy - high energy coastlines continue to transport smaller sediment so large rocks and shingles are deposited in these areas. - low energy coastlines have much smaller sediment which is only deposited in areas that have lower water velocitys - deposition includes gravity settling and flocculation (small particles are suspended in water lumps from large aggregates)
    - - erosional landforms - caves,arches,stacks and stumps occurs on pinnacle headlands, wave energy is concentrated on headlands leading to erosion, joinst/cracks are eroded first to form caves over time these caves are eroded through the headland by hydraulic action and freeze thaw expansion to form an arch, these are weatherd by wetting and drying and saltspray ebentually becoming unsupported and collapsing to form a stack this is also weatherd and eroded by similar processes to collapse futher into a stump. wave cut notch and platform - erosion is concentrated around the high tide line creating a wave cut notch as the notch becomes deeper the cliff face becomes unstable and collapses this leaves behind a platform of the uneffected cliff base, over time a wave cut platform is formed.
      - rate of retreat and cliff profile - steep cliffs rock is strong and fairly resistant to erosion absence of beach, longfetch and high energy waves premote steep cliff development, most comenly found in high energy environments. - gentle cliffs found with areas of weaker rocks which are less resistant to erosion therefore prone to sluming, large beaches reduce wave energy and prevent steep clifs forming commenly found in low energy environments. - rate of retreat dependent on the importance of marine and terrestrial factors, cliffs made of unconsolidated rocks are the most likely to retreat. - negative feedback mechanisms help to protect and restore a coast.
      - depositional landforms - beaches - beach accretion occurs due to constructive waves during summer, beach excavation occurs from destructive waves in winter. there are two types of beaches swash aligned ( wave crests approach perpendicular to the coast = limited longshore drift so sediment doesn't travel far. ) drift aligned (waves approach at an angle so sediment travels along the beach possibly forming a spit, lager sediment found at the start of the beach. -Spits- occurs when the coast suddenly changes directions, longshore drift continues to deposit sediment, changes in wid direction and wave refraction can lead to a cured spit end (recurve spit) multiple curved ends cause a compound spit can extend across bays to form barrier beaches. -barrier beaches/bays- occurs when beach or spit extends across a bay to join a headland, traps water, can form from rising sea level where glaciers deposited sediment, if it is seperated from mainland it becomes barrier islands, common in areas of low tidal range - tombolo- bar or beach that connects from the mainland to an offshore island, formed due to wave refraction off the coastal island reducing wave velocity. - offshore bars- an offshore region where sand is deposited. as waves lack energy to to carry sediment and they absorb wave energy, waves may pick up energy from an offshore bar which provides input into system, also formed when backwash removes sediment from a beach. - coastal vegetation - essential in stabilising coastal landforms, roots bind soil together reducing erosion, when submerged plants provide protective layer, plants reduce wind speed reducing erosion.
        
        more depositional landforms - sand dunes - wind blows sand landwards, large tidal range allows sand to dry making it light enough to be picked up by wind , dunes develop as a process of vegitation succession, pioner species such as rocket are resistant and able to survive in salty conditions with its roots helping to bind sand dunes together, decaying organic matter adds nutrients and humas to soil allowing marram grass to grow, climatic climax occurs when trees are able to colinise areas. - marram grass - example of pioner plant it's tough and flexable so it can cope with sandy conditions, adapted to reduce water loss through transpiration, roots can grow up to 3 meters deep and tolrate temps up to 60 degrees. - estruine mudflats and salt marshes- deposition occurs in esturies as water velocity is low, so water can no longer carry sediment in suspension, mudflats and salt marshes may occur behind spits , deposition occurs as a result of flocculation more sediment is trapped creating a medow leading to climatic climax of vegitation succesion.
      - positive feedback loops - amplifies change and makes a system more unstable taking it away from dynamic equilibrium. eg: people walking over sand dunes destroys vegetation causing erosion. roots were holding sand dunes together, damaging vegetation more susceptible to erosion this increases the rate of erosion. sand dunes eventually become completely eroded which leaves the beach open to more erosion taking the beach back further away from its origonal state.
    - - isostatic change - local changes caused by subsidence or uplift of the crust related to changes in the amount of ice or growth / erosion of mountins. eustatic change - global sea level change - due to thermal expansion contraction in global processes sea level increased 100m since the last ice age. emergant landforms - arches stack and stumps - raised beaches and relic cliffs, form when land has been raised in relation to the coastline. submergant landforms - rias (sea levels flood narrow winding inlets and river vallyes) - fjords ( sea level floods deep glacial vallyes to create natural inlets and harbours) - dalmation coasts (vallys running parallell to the coast become flooded leaves a series of long narrow rugged islands) forms when sea level rises or coastline sinks.
      - contempoary sea level change - since 1880 sea levels have increased 235m, the ippc estimate by 2100 sea level will increase 0.3m -0.1m. this could lead to aquifiers being pollouted in low lying atolls and inundate many low lying cities. it will also icrease the risk of tropical storms and tsunamies, turning coastal area into recrational land as adaptation will become more popular.
      - risks to coastal environments -storm surges- removing natural vegetation, mangrove forests provid protection against extreme weather events such as tropical storms, however many mangrove forests are destroyed to make space for tourism or housing, mangroves can help keep up with rising sea levels up to 8 times the current rate. global warming - as the surface of oceans gets warmer, it is predicted that the frequency and intensity of storms and storm surges will increase.
      - consequences of communities - reduced house and land price leading to economic loss, storm surges also damage the environment if depositional features are destroyed then erosion occurs more quickly, globally 1 million+ people live on the coasts that are at risk of flooding, as erosion increases so does environmental refugees.
      - coastal management - hard engineering (man made structures that aim to prevent erosion, normally very effective but cause more erosion in other places is also classed as a traditional method to coastal managment) - Gryones- timber protusions that trap sediment from longshore drift, builds up beach and cost effective but vissually polluting and starves beach furthr down - sea wall - concreate structure that reflects wave energy, effective and promanade has tourist benifits but expensive and visually unappeling could also reflect energy else where causing erosion - rip rap / rock armour - large rocks that reduce wave energy, cost effective but rocks are sourced from else where (dosn't fit in) and climbing hazard - revetments - wooden or concreate ramps absorbing wave energy, cost effective but vissually unapealing and need constant maintenace.
        
        coastal management - soft engineering (aims to work with and compliment physical environment is also classed as a traditional method to coastal management) - beach nourishment - sediment is taken from offshore sources to build up beach, builds up and protects beach and cost effective while looking natural but needs maintenace and dredging negativley impacts local habitats. - cliff regrading and drainage - reduces the angle of the cliff stabilising it, cost effective but cliff may collapse suddenly and may look unatural - dune stabalisation - marram grass planted letting the roots hold dunes together, cost effective and creates wildlife habitats but plantin is time consuming - marsh cration - type of managed retreat allowing low lying areas to flood, creates important wildlife habitats but farmers loose land and may need compensation.
        
        CBA ( cost benifit anylsis) - carried out before any coastal managment scheme takes place - the expected cost compared to expected benifits - may be tangible or intagible .
        
        sustainable coastal management - sustainable integrated approaches are becoming more widely used. they are holistic stratergies, they are not traditional stratergies. - managing natural resources ensuring long term productivity - new jobs for people facing unymployment due to management schemes- educating communities - about need to adapt - monitoring coastal changes- ensuring that everybody is considerd.
        
        integrated coastal zone management ( ICZM) large sections of coastline are managed by one intergrated strategie - coastal managment must be sustainable - environmental protection is prioritised over economic development - the iczm must include all stakeholders - a decision to protect one coastal area may not outway the effect of exposing another communitie to erosion.
        
        shorline managment plans (smps) - there is an smp for each sediment cell in the uk - identifies all activities natural and anthroprogenic - hold the line - no active intervension - managed retreat/ realignment - advance the line- factor cosiderd when deciding on a smp are - economic value of assets, feasability of engineering solutions and ecological and cultural values.
        
        conflict over policy decisions - winners = benifit economically, environmentally and socially - lossers might have to relocate, or lose jobs. this can cause conflict as people might have a strong sense of attachment to place.
- - - - the hazard management cycle - mitigation > preparedness > response >recovery >(repeat) prepardness - being ready for event to occur - response - immediate action - recovery - long term responses - mitigation - stratergies to lesson effects of another hazard.
  - - - hazads caused by seismic events - shockwaves - energy released from the sudden jolt that vibrates through the ground - tsunamis - caused when water is displaced from plates moving underwater, creating a large wave - liquefaction - when soil is saturated, the vibrations of an earthquake cause it to act like a liquid, soil becomes weaker and more likely to subside when it has large weight on it landslides and avalanches.
      - effects of seismic hazards -primary - environmental - earthquakes can cause fault lines which destroy the environment, liquefaction -economics - businesses destroyed - social - buildings collapse killing/injuring people and trapping them. - political - government buildings destroyed.
      - secondary - environmental - radioactive materials and other dangerous substances leaked from power plants, saltwater from tsunamis flood freshwater ecosystems, soil salinisation - economic - economic decline as businesses are destroyed tax breaks, high cost of insurance payout, sources of income lost - social - gas pipes rupture, starting fires which can kill water supplies are contaminated as pipes burst spreading disease and causing floods, tsunamis which lead to damaging flooding - political - political unrest from food shortages or water shortages, borrowing money or international aid can be inital chaos and lawlessness eg looting.
        
        response and risk management to seismic hazardous -prevention - majority can not be prevented, earthquakes and tsunamis occur regardless, liquefaction of soils can be prevented through soil stabilisation ( gravel colums put in the ground), avalanches can be prevent ed through controlled explosions - prepardness - earthquake prone areashave extensive awareness stratergies and education in place eg drop cover hold on, earthquake warning systems and tsunamis warming systems after earthquakes, evacuation plans and training - mitigation - search and rescue immediate emergency aid and evacuation, demolishing older unsafe buildings, tsunami waves breaks and sea walls - adaption - move away from at risk area, capitalise on opportunities, such as encouraging tourism, insurance if living in place of risk, changing lifestyle choises eg moving valuable items (not to fall), building specially designed earthquake proof buildings.
  - - - secondary -environmental - removing inasive species and stimulating seed germination, migration patterns of animals affected, increased co2 from fires could heighten the greenhouse effect - economic - high cost of rebuilding and insurance payout, sources of income lost, discouraging visitors, losing tourism sector, planes cancelled - social - homelessness, food shortages from destroyed agricultural land, health problems such as asthma from smoke inhalation - political - borrowing money for international aid, pressure for goverment to do more about global warming due to increased frequency.
      - responses and risk management to wildfire hazards-prevention - in current climates and weather conditions wildfires cannot be avoided overall, however human caused wildfires can be prevented through aareness, controlled burnings and fire beaters, can prevent large wildfires from starting. -preparedness - public awareness about why wildfires start, evacuation plans and training, satellite image tracking to manage the areas that are at risk, red flag warning systems so people know areas that will possibly be at risk - mitigation - search and rescue, immediate emergency aid, evacuation, removing flammable materials such as dead leaves, spraying water and fire retardent onto area, buildings materials that will not release toxic chemicals into the atmosphere - adaptation - move away from area at risk, fire breakes to stop fires spreading, reducing carbon footprint to lower c02 emissions to lower frequency, insurance to cover damage.
- - - - place meaning is shaped by the past and present connections of a place on a variety of scales from global to local - rebranding - encourage tourism by promoting the endogenous or exogenous characteristics of a place, it involves advertising campaigns, infastructure and built environment improvements, positive media coverage, tourist board managment.
        
        to achieve this community groups may levy media groups to positively or negatively portray a place, councils may invest in tourism boards to portray a positive image of a location, goverments - may set out strategies such as improving infrastructure, individuals - may start social media campaigns which suggest a different image of place.
      - place representation may take different forms; websites, songs, posters, videos, photographs and news articles. places may also be represented in - cencus data, graphs or measures such as index of multiple deprivation. - geo spatial data such as choropleth maps.