Physical Paper 1-water Flashcards
What is an input
The addition of energy and or matter into a system
What is an output
The results of a process within a system
What is a system
A set of interrelated components working towards some kind of process
What is an open system
Where matter and energy can be transferred in and out of the system boundary into the surrounding environment
What is a closed system
Transfer of energy both in and out of the system boundary but not the transfer of matter
What is an isolated system
No interactions with anything outside their system boundary. No Imput or output of energy or matter
What is dynamic equilibrium
When Imputs and outputs of a system are balanced despite changing conditions. However if one of the elements changes then the equilibrium will be distrusted and imputs inc and outputs don’t their is feedback as a result.
What is positive feedback
Where the effects of an action are enhanced or multiplied by subsequent knock on effects
What is an example of positive feedback
Global temps rise- ice melts- releases trapped co2- more heat trapped in atmosphere- global temps rise more
What is negative feedback
Where the effects of an action are reduced or nullified by subsequent knock on features
An example of negative feedback
Humans burn fossil fuels- increased co2 in the atmosphere- increased plant growth- inc uptake of co2 by plants
What are earths 4 major subsystems
Atmosphere, hydrosphere, lithosphere, biosphere
Summary of atmosphere
Gaseous layer that envelopes the world ‘air’ is held around the planet by the force of gravity
Summary of lithosphere
Solid outermost part of earth made up of mostly rock. Includes crust and upper mantle
Summary of hydrosphere
All water on earth collectively. Found in air,soil,glaciers,oceans,rivers,lakes,streams. Also found in solid liquid and gas.
Summary of biosphere
Water found in all the living organisms on earth- found in all earth spheres
What is a water store and examples
Places where water is held for a period of time. Oceans,lakes,rivers,puddles,atmosphere,ground,aquifers,plants,ice
What is a water transfer and examples
Processes involved in transferring water between stores. Precipitation, evaporation, condensation,transpiration,surface run off,infiltration
Links between hydrosphere and atmosphere
Water is a component of air, water cycle, gasses trapped in ice, oceans store carbon
Links between hydrosphere and lithosphere
Soil has water, freeze thaw weathering, hydraulic action in a river erodes rocks, plate movement can cause tsunami
Links between hydrosphere and biosphere
All living things need water to survive, photosynthesis, some animals live in water
Inks between atmosphere and lithosphere
Gasses get trapped in rocks, fossil fuels release co2, volcanic ash releases co2 into the atmosphere
Links between atmosphere and biosphere
All living things respire, cows release methane, photosynthesis, decomposition
Links between lithosphere and biosphere
Animals live in soil, formation of fossils, porous rocks have insects, plant roots stabilise soil and grow into rocks, decomposition
How much water is stored in oceans
96.5%
How much freshwater is stored in glaciers and ice caps
68%
How much surface water is stored in the ground
69%
How much freshwater is stored in underground reserviours
30%
Oceanic water details
Cover 72% earths surfaces and 97% earths water. Water is saline- salt makes up 3.5%. It’s alkaline-8.14 but has fallen due to atmospheric carbon. As acidity increases it causes problems with respiration, photosynthesis and so on.
What is the crysphere and what does it include
Portions of earths surface where water is solid- ice.
It includes- sea ice, permafrost, ice caps, alpine glaciers, ice sheets
What are ice caps
Thick layers of ice on land that are smaller than 50000km2 normally in mountainous areas- starting point for many glaciers. E.g ice cap on Mount Kilimanjaro in Africa is its only remaining ice cap and is rapidly melting.
What are ice sheets and examples
E.g Greenland and Antarctica- sea levels rise is melts. Ice shelves are platforms of ice that form when ice sheets and glaciers move out into the ocean. Ice bergs are chunks of ice that move into ocean after breaking of ice shelves. Huge mass of ice- layers of snow pile up. Flowing downhill under own weight. Frozen all year round
Alpine glaciers and examples
Found in deep valleys or upland hollows. Are fed by ice caps. Important in Himalayas- supply water for glaciers e.g indus and Ganges. Lifeline of millions of people in south Asian countries su h as nepal Pakistan India and Bangladeshi
What is perma frost
Ground water that remains frozen for atlas 2 years. 1-1500m as climate warms permafrost has begun. To melt which releases large amounts of carbon.
What is the tryophere and types of terrestrial water
All the surface or underground water. Includes ground water, surface water, soil water, biological water
Surface water, examples and extra info
Free flowing water of rivers, ponds and lakes. Rivers act as a store and transfer of water in a canal. E.g the amazon river which is the largest in the world 1/5 total river flow. Lakes- collection of freshwater found 8n hollows of lands surface. E.g capstan sea- largest. Wetlands such as marsh and peatland are crutial for global biodiversity
Ground water
Water that collects underground in porous spaces of rock. E.g bore hole in northern Russia- 13km deep. The depth at which pore spaces become completely saturated is called the water table. The amount of ground water is rapidly decreasing due to extraction for irrigating farmland in dry areas.
What is soil water
Is that which is held together with air in unsaturated upper layer of earth. Fundamental for many hydrological, biological processes. Soil moisture key in controlling exchange of water and heat energy between lands surface through evaporation and plant transpiration. Development in weather and precipitation levels.
What is biological water
All water is stored in earths biomass (living things) it varies across the world depending on vegetation type e.g rainforest stores far more water. Treees take in water from roots and transported and stored in trunks and branches and then lost through transpiration through stoma. Plants can be adapted to hold water- cacti.
Atmospheric water stores
Water held In the air. It exists in 3 states- solid liquid gas. The amount of water that can be held depends on temp of the air- hot can hold more that’s why poles are dry and equator is humid.clouds are a visible mass of water droplets suspended in the atmosphere. Clouds are formed due to air in the lower layers of atmosphere being saturated due to cooling and when these grow it causes rain. Water vapour is important as it absorbs, reflects and scatters solar radiation keeping earth at a good temp.
What is the analyse question structure
Pattern- general trend
Evidence- data
Anomaly-does not fit trend
Link-links between data sets
Manipulate- %change,range,mean
What is precipitation
Transfer of water from atmosphere to ground: rain,sleet,snow,hail
What is evaporation in terms of phase change
Transfer of water from liquid to gas. Most happens from oceans
What is condensation in terms of phase change
Transfer of water from gas to liquid e.g clouds
What is sublimation
Solid(ice)- gas(water vapour)
What is deposition is phase change
Gas(water vapour) to solid (ice)
What is latent heat
Energy absorbed or released by a substance during a change in its physical state that occurs without changing its temperature.
Why is evaporation caused
Energy from solar radiation hitting surface of land or water
Factors that might affect the rate of evaporation
-temp of air- warmer can hold more
-how much water there is
-amount of sunlight
-humidity- closer air is to saturation the slower rate of evaporation
What is the dew point
When air cools then it will get to a temperature which it becomes saturated
What happens at dew point
Excess water is converted to liquid in condensation.
What can water molecules condense on in the air
Tiny particles such as smoke or dust. Or surfaces such as leaves and windows, these must have a temperature below the dew point. If below freezing deposition happens- frost
What is a low pressure zone known as in tropical rainforests
ITCZ (intertropical convergence zone)
What is the process of frontal rainfall
Warm less dense air and cold dense air are separated by a front. The warm air is forced to rise over the cold air. It cools and condenses to form clouds and precipitation.
What is relief rainfall process
Evaporation of the sea and prevailing wind forces warm air to rise up the mountain. Air cools and condenses to form clouds and leaves a rain shadow on the other side. Dry air descends and warms.
What are cryspheric processed key terms and what they mean
Accumulation- imput of snow/ice into an area
Abiation- the removal of snow/ ice out of an area
What is the water balance
Within a drainage basin when is balance between inputs and outputs
What is stem flow
Precipitation that reaches ground after being interrupted by stems/leaves etc.
What is throughfall
Precipitation which reaches ground directly
What is throughflow
Down slope through soil
What is groundwater flow
Water moving through underground rocks
What is perculation
Downwards movement of water within the rock under the soils surface depends on nature of rock
What does a hydrograph show
River discharge and precipitation- shows how river discharge changes in response to precipitation
What is a flashy response hydrograph
A hydrograph which is associated with a sudden flood event called a flash flood
What is a slow response hydrograph
An identical rainfall event will lead to a less steep rising limb. Peak discharge is lower and lag time is longer- flooding less likely
What is the lag time
Time difference between peak discharge and peak rainfall
What is storm flow on a hydrograph
Additional flow of a river in response to the storm
What is base flow on a hydrograph
Normal flow of the river when fed by groundwater
What is rising limb
Shows how quickly the discharge rises after a rainstorm
What is the falling limb
Shows reduced discharge once the main affect of the runoff has passed
What are some factors that affect flood hydrograph shape
Size of drainage basin
Rock and soil type
Type of slope
Vegetation
Some physical factors affecting hydrographs
Steep sides vs gentle slopes
High density vs low density
Saturated vs unsaturated soil
Surface backed in sun and not
Snowfalls vs rainfall
Large vs small drainage basin
Human factors affecting flood hydrographs
Deforested vs not
Ploughed fields vs not
Terraced fields vs not
Animal grazing vs none
Urbanisation and before
What is a river regime
The variability of a rivers discharge through the course of a year in response to precipitous, temp,evapotranspiration and drainage basin characteristic
What are the 3 land use changes affecting the water cycle
Deforestation
Soil drainage
Water abstraction
Why are rainforests important to the water cycle
390b trees in amazon such up water from deep roofs and realeasing through leaves through transportation
One tree moves 100 gallons no of water each day
Critical moisture for agriculture
Amazon needs 80% trees standing to continue with the hydrological cycle and its at 81%
Localised deforestation before deforestation
P returned to atmosphere by ET and SR is minimal. Water reaches forest floor infiltrates and slowly moves back to river
Localised deforestation after deforestation
Lower ET because new vegetation has fewer leaves
SR increases due to lack of vegetation due to localised flooding
Extensive deforestation initial impacts
Extensive rainfall can lead to positive feedback loop. Initially ET is lower meaning much of water leaves the area via river channel rather than being recycled by the forest and atmosphere
Extensive deforestation long term impacts
Water is leaving the area via rivers so there is less water vapour available in atmosphere for precipitation to occur because there is less precipitation less water reaches river channel and flow is reduced.
What does subsurface drainage do
Removes access water from soil profile carried out through a network of tubes referred as tiles installed 60-120m below the surface
How does soil drainage work
When water table is higher than the tile water flows into the tubing through holes in the tube. This lowers the water table to the depth of the tile over corse of several days
Tiles allow excess water to leave the field
Once lowered no more water flows through them
Advantages of soil drainage
Improves soil structure which makes it easier to work with and allows for greater root penetration enabling roots to travel faster and further.
Improves aeration- more air spaces- microorganisms thrive and increases rate that organic matter is broken down so plant nutrients are able to form and root respiration
Heavy machine can work on soil without danger of compaction (would inc overland flow)
Large amount of animals can graze on land without compacting soil
Disadvantages of soil drainage
Insertion of drains artificially increases speed of through flow (water moving through soil layer) and water enters water sources quickly and increases risks of flooding
Reducted navigability of river as flow regimes are more variable whereas Before flow remained even throughout year
Dry topsoil can be subject to wind erosion if not properly protected
Nitrate loss and can lead to eutrophicication- disturbs organisms and reducted quality of water
Where is groundwater used and what does it cause
Large parts of Europe- dominant source of freshwater and there is more water being taken out than recharged cause water scarcity which could lead to shrinking water tables, empty wells, higher pumping costs and intrusion of salt water in coastal areas
What is salt water intrusion
When saline water begins to contaminate freshwater aquifers and ground water supply as a result of abstraction
Explain how water abstraction can affect the water cycle at different spatial scales
In Italy overexploitation of the river in the region of Milan has led too 25-40m decrease in groundwater levels over the last 80 years therefore less water is travelling and being evaporated and so this results in low precipitation and therefore less water sources.
In north london groundwater risen 8-15m due to limited abraction which could be a risk to flooding as increased surface run off and river discharge. Whereas in south has decreased by 10m due to more abstraction and is at risk to saline intrusion- decreased precipitation and evapotranspiration
What is a drainage basin
Area around a river where water will always end up back in the river
What is the case study of a river catchment at a local scale
River greta located in Keswick in Lake District national park
physical land factors affecting flood risk to river greta
- the town is a valley and surrounded by areas of high land- fast water flow
-surrounding land steep- RELEIF
-high density drainage basin- quicker lag time- more flow
-limited areas of forest- upland areas are grasses/ferns so less interception- VEGETATION
-GEOLOGY- sedimentary and igneous
Human factors affecting flood risk to river greta
-high level of urbanisation due to tourists with impermeable surfaces which increases surface run off so more water gets back to the river- LAND USE
-lots of drainage so water feeding directly back to the river- inc flood risk- subsurface drainage systems- golf course
-lowland areas used for pasture land for sheep/cattle which increases compaction of soil- less can infiltrate
MANAGEMENT- schemes
What are links between Keswick climate and river regime
Climate is mild so less moisture can be held in air so limited evapotranspiration across the drainage basin.
Rainfall maximums in winter (relief rainfall and winter storms) so peak discharge is in winter months
Snowfall in upland areas during winter months- rising discharge in spring as the snow melts
What is sedimentary rock
Formed from layers of sediment building up in the ocean and becoming compressed over time
What is igneous rock
Formed when rock is molten and cools over time
Extrusive- cools on earth surface
Intrusive- cools inside earth
What is metamorphic rock
Formed when igneous or sedimentary rock are subjected to intense heat and pressure changing the Rock
Is sedimentary rock permeable or impermeable
Permeable- softer
Is igneous rock permeable or Impermeable
Impermeable- harder
How does geology affect flood risk near river Greta
Lots of igneous- impermeable rock mostly in south which increases surface run off which increases flood risk
Some sedimentary rock- permeable- increase infiltration in north
Higher flood risk in south
How does river management affect the flood risk of river Greta
In Keswick: flood walls, drainage holes, embankments.
Reduced risk of flooding for 182 properties, a 1.3% chance of flooding in any one year
Thirlmere reserviour supplies water to Lake District
What was a flood event in a river catchment at a local scale
2015 flood event in Keswick
What are human factors that led to the 2015 flood event in Keswick
Management schemes such as defence wall were overtopped and outflanked
What are physical factors that led to the 2015 flood event in Keswick
December was wettest calendar month on record-24 hour rainfall- 341mm
Rainfall fell on already saturated ground flowing from three previous storms
Peak flow- 3.75m
