Water cycle EQ1

Question 1

describe the hydrological cycle

Answer 1

a closed system
driven by solar energy & gravitational potential energy
is a fixed amount, not external inputs or outputs
3 states within the system - solid, liquid & gas
stocks = where water is held
fluxes = the rate of flow between stores
processes = physical mechanisms which drive fluxes

Question 2

what is the crysophere ?

Answer 2

frozen water stores on earth

Question 3

what is blue water ?

Answer 3

water stored in rivers, lakes etc and groundwater in liquid form ( visible )

Question 4

what is green water ?

Answer 4

water stored in soil and vegetation ( invisible )

Question 5

what is fossil water ?

Answer 5

not renewable or for human consumption

Question 6

what is a drainage basin ?

Answer 6

any area of land where precipitation collects or drains off of into a common outlet

Question 7

how does climate affect the drainage basin ?

Answer 7

influences the type and amount of precipitation overall as well as the amount of evaporation
also impacts vegetation which influences the amount of green water

Question 8

how does soil affect the drainage basin ?

Answer 8

determines the amount of infiltration and through-flow
also affects type of vegetation

Question 9

how does geology affect the drainage basin ?

Answer 9

impacts percolation and groundwater flow

Question 10

how does relief affect the drainage basin ?

Answer 10

altitude impacts precipitation totals as well as the amount of run off

Question 11

how does vegetation affect the drainage basin ?

Answer 11

the amount of interception, infiltration and overland flow will be impacted by more or less vegetation

Question 12

what is a water budget ?

Answer 12

the annual balance between inputs and outputs
can be global or local scale
can have a surplus or deficit balance

Question 13

how does over abstraction affect drainage ?

Question 14

how does deforestation affect drainage ?

Answer 14

because tropical forests thrive on thin soil, removing the canopy affects this top soil and then impacts the natural water cycle

Question 15

how does changing land use ( urbanisation ) affect drainage ?

Answer 15

more impermeable surfaces = reduced infiltration & increased run off
urban drains = water enters river systems quicker and can flood quicker

Question 16

how do reservoirs affect drainage ?

Answer 16

delay the natural flow of water & removes it from the drainage basin

Question 17

what is afforestation ?

Answer 17

the planting of trees in an area that hasn’t been forested in recent times

Question 18

describe orographical rainfall

Answer 18

prevailing winds blow air from sea
relief pushes air up until it cools and condenses
then precipitates

Question 19

describe cyclonic rainfall

Answer 19

warm moist air rises when it meets a colder air mass
the warm air condenses and forms clouds
a warm front causes mild to moderate prolonged rainfall
cold front = warm air rises and causes unstable weather

Question 20

describe convectional rainfall

Answer 20

the sun heats the ground and the ground absorbs and reflects this heat
causes the air above the ground to warm too
air rises and condenses at higher altitudes
common in tropical areas and can happen with little warning

Question 21

what is a rain shadow ?

Answer 21

a dry area of the leeward side of a mountain that gets little rain due to the mountain sheltering it
e.g the Owens valley in California

Question 22

what are the 6 flows of the drainage basin ?

Answer 22

1. interception = retention of water by vegetation and soil
2. infiltration = water absorbed or soaked into soil
3. percolation = deep transfer of water into permeable rock
4. throughflow = transfer of water down slope through soil
5. groundwater flow = flow transfer or percolated water through permeable or porous rocks
6. surface run off = movement of water that is unconfined by a channel across the grounds surface

Question 23

what are the 3 outputs of the drainage basin ?

Answer 23

1. evaporation = moisture lost directly into the atmosphere from water surfaces, soil & rock
2. transpiration = water lost through the stomata of plants through respiration
3. channel flow = flow of water now confined to a channel

Question 24

what is a river regime ?

Answer 24

the annual variation in discharge of a river at a particular point

Question 25

what is a storm hydrograph ?

Answer 25

the variation in a rivers discharge at a specific point over a short period of time
usually in a storm event

Question 26

what are the 3 main aspects of a storm hydrograph ?

Answer 26

1. lag time = the time interval between peak rainfall & peak discharge
2. recession limb = when the discharge starts to decrease
3. base flow = the normal day to day discharge of the river

Question 27

what is a flashy storm hydrograph ?

Answer 27

one with a short lag time, steep rising and recession limb

Question 28

what is a subdued storm hydrograph ?

Answer 28

one with a long lag time, more sloped rising and recession limb

Question 29

what 3 factors affect the shape of a storm hydrograph ?

Answer 29

1. rock type = impermeable = increased run off = flashy
   permeable = more percolation = subdued
2. vegetation = low density = lower interception = rapid movement = flashy
   high density = opposite so subdued
3. human activity = impermeable surfaces = flashy
   permeable = subdued

Question 30

what is a flood

Answer 30

an event that occurs when the discharge of a body of water is of sufficient quantity to overflow it’s channel and submerge the surrounding land

Question 31

what areas are most at risk from flooding

Answer 31

1. low lying regions / river estuaries
2. low lying urban regions
3. areas with small basins