Hydrosphere Flashcards
Past Paper Question related to the Hydrosphere
Use the information to explain why the stratosphere is not involved in the hydrological cycle. (2)
low temperature;
water vapour condenses (before reaching stratosphere)
Explain how the change in ocean currents during El Niño years affects coastal regions around the Pacific Ocean. (4)
changes in current temperatures;
change in moisture-holding capacity of air;
less moisture reaches coast where current is cooler;
more moisture reaches coast where current is warmer;
correct reference to named area;
Explain how the conditions for life on Earth are affected by high heat capacity of water. (2)
slow temperature change;
reduces temperature extremes;
transfers heat via ocean currents;
reference to named area to illustrate;
Explain how the conditions for life on Earth are affected by solvent properties of water. (2)
named solute;
named function for living organisms;
Explain how fitting water meters in homes affects water use. (2)
payment per volume used/knowledge of volume used;
encourages conservation/usage reduced/wastage reduced;
[A named method of reducing usage/leakage]
[R meter restricts the amount of water available]
Explain how greywater use may help to increase water availability. (2)
recycling(of used water);
[R rainwater]
to reduce use of more purified water/for low quality use/example of use;
Explain how artificial aquifer recharge may help to increase water availability. (2)
surplus surface/river/rain water;
pumped into aquifer/allowed to infiltrate from lagoon/reservoir;
increase availability when surface water is insufficient;
Outline two ways in which water shortages cause problems in Less Economically Developed Countries. (4)
stated problem;
impact of problem;
eg
hygiene named disease/pathogen/health problem
lack of irrigation water
reduced food supplies
industrial development
problem stated industrial use of water
Residence time. (1)
Quantity in reservoir/ annual rate of inflow or outflow
Explain the meaning of the term dynamic equilibrium with reference to the processes affecting the amount of water present in surface storage. (2)
Processes that maintain balance/effects cancel out;
Minimum 2 processes with counteracting effects;
Suggest two ways that vegetation may affect the movement of water in the hydrological cycle. (4)
Process/involvement of plants; How it affects movement of water/quantity in reservoir; eg Transpiration/stomata Soil/vegetation to atmosphere
Leaf interception
More in atmosphere/less on/in soil
Roots/leaf litter
Reduced runoff/more infiltration
Use examples to explain the difference between abstractive and non-abstractive uses of water. (2)
Abstractive:
Removed from source for named use;
eg
Named public water supply use/industrial washing /solvent/irrigation
Non-abstractive:
Not removed from source for named use;
eg
Hydro-electric power/shipping/recreation/wildlife conservation
wetland management/other named non-abstractive use
Explain how the use of aquifer water for irrigation in some areas has caused crop death through soil salinisation. (2)
Osmotic dehydration; Saltwater incursion (into aquifer) / water evaporates and salt concentration increases
Outline two ways that the storage of river water in a reservoir reduces the need for further treatment. (4)
process in reservoir/treatment process not needed;
one linked explanation;
eg
sedimentation/settling
static water/turbidity/particles/suspended solids
[A filtration not required]
sterilisation/UV light/ozone treatment/chlorination pathogens killed/removed
aeration
reduction of odours/dissolved metals
activated carbon filters
degradation/adsorption of organic substances/pesticides
[R screening/litter removal/reverse osmosis not needed]
Explain how very large reservoirs may alter the temperature extremes in the surrounding area. (2)
reduced (extremes)/more constant temperature;
high heat capacity/thermal mass;
heat storage/heat absorbed and released later/slow temperature change;
role of wind in heat transfer;
OR
reduced (extremes)/more constant temperature;
increased evaporation/cloud cover; increased albedo/reduced IR transmission;
Outline two other ways that very large reservoirs may change the microclimate downwind. (4)
increased cloud albedo;
reduced sunlight;
low friction;
increased wind speed;
increased evaporation;
increased humidity/increased precipitation/named form of precipitation;
Suggest why the long-term use of groundwater for irrigation may make the cultivation of some areas impossible. (2)
salt/salinisation/salt water incursion; toxic/osmosis/dehydration;
Explain why increasing the availability of treated water for domestic use in Less Economically Developed Countries (LEDCs) may increase social and economic development. (4)
increased personal hygiene/fewer water-borne diseases/pathogens;
named water-borne disease/pathogen;
eg typhoid/cholera/polio/dysentery/diarrhoea/Bilharzia/E. coli
less time spent fetching water;
lower mortality/less debilitating disease; can do more work/attend school; can do more work so increased income;
less money spent on treating preventable health problems;
reduced conflicts over water supply;
Describe how sedimentation lagoons reduces environmental problems. (2)
time/static;
suspended solids/particles settle (in lagoon);
[R sedimentation without reference to particles]
reduces sedimentation/turbidity/light penetration problems (in river);
Describe how water spraying reduces environmental problems. (2)
particles become heavier/stick together/increases cohesion/clumps;
dust reduced/settles;
Outline one method that may be used to measure the pH of mine drainage water. (2)
pH meter;
calibrated;
or
universal indicator/pH indicator paper/solution;
colour chart/comparison/colorimeter;
[R litmus, reference to choice of only two colours]
Explain why there is very little water vapour in the stratosphere. (2)
(upper) troposphere/below stratosphere is below zero/very cold;
water vapour condenses/freezes/falls as precipitation
Mine drainage water can alter the pH of the rivers into which the water is discharged.
Describe one method that can be used to measure the pH of mine drainage water. (2)
electronic pH meter/probe;
calibrated;
or
Universal indicator solution/papers;
[R litmus paper] colour comparison/colour chart/colorimeter;
Outline two other environmental problems for local rivers, which may be caused by mine drainage water, and suggest how the mine drainage water may be treated to control each problem. (4 [2+2])
problem;
linked solution;
eg
turbidity/suspended solids
sedimentation/filtration/settling
or
heavy metal leachate
lime/high pH reduced solubility/ phytoremediation/electrolysis
[R toxic leachate unless qualified]
or
altered river flow rate
control of pumping rate
or
phosphates
iron salts/flocculation/reed bed/ phytoremediation
or
soluble iron
aeration
or
cyanide
oxidation/use of SO2
Describe two environmental problems caused by the overexploitation of aquifers. (4)
2 linked points;
eg
reduced aquifer pressure
lowered water table
drying of named surface water feature/impact on named taxon
saltwater incursion
contamination of drinking water/irrigation water/soil water
reduced water support/reduced pore water pressure subsidence
credit any point once only
Suggest how the residence time of water in land ice is affected by human activities. (2)
reduced RT;
increased melting/reduced freezing;
Explain why rock P and rock R must have different permeabilities to allow rock Q to form an aquifer. (2)
P: high permeability for recharge;
R: low permeability/impermeable to retain water;
[AP: permeable for recharge if impermeable for R]
Name one rock that often forms aquifers. (1)
chalk/sandstone/limestone;
[A sand/ gravel]
Outline two advantages of exploiting water from aquifers rather than from rivers. (2)
low risk of named pollutant and named treatment process unnecessary or provided naturally;
low risk of named pollutant and problem caused;
more predictable availability;
measurable stored volume/less affected by supply fluctuations;
reduced impact on river flow;
no evaporative losses; health benefit of named mineral ;
Outline how human activities have increased the acidity of the sea. (2)
named human activity that produces CO2;
[A methane production]
carbonic acid/HCO3 ions;
Explain how forest uses may affect the reservoir. (2)
(evapo)transpiration losses/increased interception so reduced water volume;
reduced soil erosion so less sedimentation/reduced turbidity;
slower/less flow reduces nutrient/pollutant inflow to reservoir;
water retained by soil so more even inflow;
conifers increase acidity so pH reduced;
dead organic matter from forest causes deoxygenation;
Explain how urban areas may affect the reservoir. (2)
impermeable surfaces/reduced infiltration/drainage systems so increased runoff/increased volume of inflow;
more rapid runoff so greater fluctuations in water level;
named urban pollutant carried into reservoir;
Suggest how the presence of the dam may affect wildlife upstream of the reservoir. (1)
barrier to migration/dispersal/colonisation
Explain how the porosity and permeability of a rock affect its suitability as an aquifer. (4)
porosity
storage volume;
high porosity more suitable;
permeability
rate of water flow;
high permeability more suitable;
Describe two positive feedback mechanisms that affect global climate, which involve a change in the state of water. (4)
initial change involving change in state of water;
details of positive feedback mechanism;
eg
increased temperature causes increased evaporation
water vapour (acts as GHG)
increased temperature causes ice to melt
reduced albedo/reflection
increased temperature causes permafrost/soil ice/methane hydrate to melt
release of methane
increased evaporation of soil water
more CO2 from vegetation fires/decomposition
reduced temperature causes ice to freeze increased albedo/reflection
[R cause without impact][R impact without cause]
Describe the changes in density as water cools from 10 °C to its freezing point. (2)
density increases then reduces;
change at 4°C;
or
density increases to 4°C;
density decreases below 4°C;
Explain the significance of these changes for the survival of aquatic life. (1)
ice floats, liquid water beneath;
[R answers based on insulation]
Outline how aeration improves water quality. (1)
(adds oxygen to aid) removal/destruction of named substance; eg hydrogen sulfide organic matter pathogens/microorganisms dissolved/toxic metals odour/taste
Outline how activated carbon filters improve water quality. (1)
adsorption/removal of pesticides/organic materials/microorganisms/ chlorine;
Name one method of water sterilisation. (1)
ozonation/ozone/UV/ultra violet/boiling/distillation
Describe how suspended clay particles are removed from the water. (3)
flocculation/addition of flocculant/ addition of coagulant/alum/ polyelectrolytes/named flocculant/named coagulant;
neutralisation of (surface) charges;
coagulation/particles join together;
clarification/sedimentation/settling/microscreens/filters;
Outline the process of reverse osmosis (2)
high pressure;
partially permeable membrane/polyamide tubes;
[A semi-permeable membrane/selectively permeable membrane]
Explain why draining waterlogged fields results in an increase in soil nitrate levels. (2)
aerobic conditions/increased oxygen/aeration;
nitrogen fixation/nitrification;
reduced denitrification; increase decomposition of dead organic matter;
[A description of process]
Suggest two reasons to explain the fluctuations in the pH of the river water. (2)
time-related factor that may affect results;
eg
fluctuation in rainfall/runoff
snow melt
fluctuation in evaporation
changes in pumping/discharge from mine/mine activity intermittent addition of lime
Outline the difference between abstractive and non-abstractive uses of water. (2)
removed or not removed;
correct link to abstractive and non-abstractive;
Suggest why the presence of a dam has affected wildlife in the river. (1)
barrier to migration/named habitat change that affects survival;
eg
changed temperature/oxygen/turbidity/flow rate (outside range of tolerance)
Suggest why the presence of a dam has affected the turbidity of the river water downstream. (1)
reduced due to sedimentation in reservoir;
reduced turbidity/due to reduced flow rate/reduced energy reduces erosion/sediment pick up;
[A converse]
Suggest how bedrock permeability affects the choice of a reservoir site. (1)
low permeability to reduce losses; [A converse]
Outline the advantages and disadvantages of providing water for public supply from aquifers rather than from rivers. (6)
Advantages (of aquifers);;; named pollutant that is less likely (natural) filtration (by rock)/lower turbidity less rapid flow fluctuations no evaporation named treatment process not needed eg screens sedimentation
Disadvantages (of aquifers);;; energy use/cost of borehole/pumping slower recharge/slower recovery following over-exploitation/pollution subsidence named consequence of lower water table increased hardness only possible with porous permeable rock named suitable rock eg sandstone chalk limestone [R unqualified cost]
Explain why a change in state between solid, liquid, and gas properties of water are important for living organisms. (2)
named process involving change in state and function for living organisms;;
eg
evaporative cooling
transpiration transport in plants
evaporation for distribution of water
condensation for cooling(clouds)
melting ice ensures river flow in dry season
Explain why high specific heat capacity of water are important for living organisms. (2)
slow temperature change/large amount of energy needed to change temperature/reduced temperature extremes/stable temperature;
enzyme function/stated benefit for living organisms;
Explain why the anomalous expansion when cooling of water are important for living organisms. (2)
reduced density of water on cooling/below 4oC;
convection stops/ice protects water below from freezing/water below ice is warmer;
albedo for temperature control;
Explain how the ocean current, the North Atlantic Conveyor, may be affected by rising atmospheric temperatures. (4)
Greenland/Iceland/land ice melts and (freshwater) flows into sea;
reduces salinity of seawater;
(less saline) water does not sink/is less dense;
current slows;
Explain the difference between infiltration and percolation. (2)
Infiltration – (water) flow into the ground;
[A absorbed by]
percolation – flow through ground/between rock/soil particles;
Explain the difference between porosity and permeability. (2)
Porosity – space volume/amount of water that can be held;
permeability – rate of flow of fluids through;
[R ability]
Name 2 human activities that add large amounts of water vapour to the atmosphere. (2)
Reservoirs/dam;
irrigation;
power station/cooling towers/water cooling in named industry;
hydrocarbon/fossil fuel/hydrogen/biofuel combustion;
afforestation;
named activity that results in global warming;
Suggest why this extra water vapour does not produce a long-term increase in atmospheric water vapour. (1)
Condensation/precipitation/short residence time;
Outline the properties of a rock that make it suitable to form aquifers. (2)
High porosity;
high permeability;
[R description of base/cap rock]
Suggest why the overexploitation of the aquifer near Tripoli has caused the aquifer to become contaminated with salt water. (1)
Lowered water table/level/cone of depression/reduced pressure;
inflow of seawater/saltwater incursion/recharged with salt water;
Outline one advantage of exploiting aquifer water rather than desalinating seawater. (1)
Less energy/pressure/cost (of exploiting aquifer water);
[A converse relating to desalination]
Explain why river water usually requires more treatment than aquifer water to make it potable. (4)
(Aquifer/cap rock) acts as a filter;
aquifer water composition changes slowly so easier to monitor/predict;
river water changes quickly so precautionary treatment needed;
named contaminant more likely in river;;;
eg soil/turbidity/suspended solids floating solids/plastics/named debris bacteria/pathogens/sewage pesticides fertilisers heavy metals/named toxin
Describe how the domestic use of water from public supplies may be reduced. (4)
Changed behaviour;;
eg
shower instead of bath
shorter showers/smaller baths/turn off taps
full wash in washing machine/dishwasher
water meter/conservation encouraged by pricing
use of bans - hosepipe bans
water saving equipment;; eg low water use dishwasher/washing machine hippo bags automatic sensor/timed/manual pump taps/flush/dual flush spray taps push taps low water-requirement plants
reduced losses;; eg domestic appliance maintenance pipe leak reduction mulching
low quality uses of untreated water;; eg dual supply rainwater collection grey water reuse
Outline how the leaching of nutrients from fields may cause water pollution. (2)
Eutrophication; algal bloom; [A increased (water) plant growth] shading/death of macrophytes; decomposition; deoxygenation;
Describe the ways in which water supply problems may affect the social and economic development of a country. (5)
Problems;;; eg low volume available/availability limited by cost accessibility unreliable supply fluctuating supply storage difficulties quality issue dirty pathogens disease vectors toxic pollutants natural toxins hardness turbidity pH salinity competition for supplies
Social impacts;;; eg named health issues disease diarrhoea dysentery cholera typhoid polio bilharzia hygiene problems time spent collecting water time not spent on other activities restricted choice of uses/named restricted activity eg irrigation impact on named lifestyle issue eg food supply
Economic impacts;;; eg treatment cost named (expensive) treatment process named restricted industrial activity eg textiles, heating, food processing, irrigation, farming
Describe the advantages and disadvantages of exploiting the different sources of water that may be available for public supply. (10)
Named source;;; advantages;;; disadvantages;;; eg aquifers naturally filtered low turbidity low pathogen content no surface land use conflicts low treatment costs predictable supply salinity of aquifer water dissolved minerals need for suitable geology danger of over-exploitation/impact on surface water features subsidence risk of salinization/salt water incursion high volume may hide low recharge rate high cost of borehole drilling
reservoirs: low turbidity (due to sedimentation) low treatment costs reliable supply high turbidity (due to erosion) silting up need for river suitable topography suitable geology land use conflicts pollution risk cost of dam construction
rivers: no expensive structures/development costs flow fluctuations pollution risk competition for river use high treatment costs
sea: huge volume geographical restrictions salinity high energy use high treatment cost
effluent/greywater supplement supplies when other sources are limited contaminant content not potable high treatment costs rainwater harvesting low collection cost low treatment cost unreliable supply
