THE WATER CYCLE AND WATER INSECURITY EXAM
NEWEST 2024 ACTUAL EXAM COMPLETE 150
QUESTIONS AND CORRECT DETAILED ANSWERS
(VERIFIED ANSWERS) | VERIFIED ANSWERS
What is meant by a store and a flow? - ANSWER: A store is where water is held for
varying amounts of 'residence' time. A flow is the movement of water between
stores
Identify the three largest stores in size order - ANSWER: 1. The oceans
2. Icecaps and glaciers
3. Groundwater
Which two water stores are non-renewable, and why? - ANSWER: 1. Fossil water:
old, deep groundwater from former wetter periods
2. Losses from the cryosphere: melting of ice as a result of global warming
Distinguish between blue and green water - ANSWER: Blue water is stored in rivers,
lakes and groundwater in liquid form — a visible part of the hydrological cycle. Green
water is water stored in the soil and vegetation — an invisible part of the
hydrological cycle
Why is the hydrological cycle a closed system? - ANSWER: There are no external
inputs and outputs. It is a self-contained entity. Some might argue solar energy,
which drives the cycle, is an input
What is the water budget, and why does it vary from place to place? - ANSWER: The
water budget of a place is the difference between the amount of water gained from
precipitation and the amount lost as a result of evapotranspiration. The budget is in
surplus when precipitation exceeds evapotranspiration. It is in deficit when the
situation is reversed. It varies from place to place because climate (precipitation and
temperature) does
What are the main inputs of a drainage basin system? - ANSWER: Precipitation. Also
possibly water from a tributary basin
What are the main outputs of a drainage basin system? - ANSWER: Evaporation,
transpiration and river discharge
How does relief affect the inputs and outputs of a drainage basin? - ANSWER:
Altitude will affect the precipitation input (orographic rain or snow). The steepness
of slopes will affect the rate of runoff — the steeper the slope, the faster the rate
, Distinguish between interception and infiltration - ANSWER: Interception is the
process by which water is stored in the vegetation. Infiltration is the process by
which water soaks into, or is absorbed by the soil
How does geology affect the flows in a drainage basin? - ANSWER: Geology affects
the balance of the flows by which precipitation reaches a river. Where the geology is
hard and impermeable (e.g. granite), there will be much surface runoff and relatively
little infiltration and percolation. Where rock is porous, then the balance will be the
reverse with little runoff and much percolation and water reaching the river via
through flow and groundwater flow
Describe how deforestation is affecting the Amazon basin - ANSWER: The amount of
water returning to the atmosphere by evapotranspiration is greatly reduced — from
75% to 25% of intercepted water. More precipitation enters the river by runoff.
Overland flow increases the amount of soil erosion. Huge quantities of soil are
entering the rivers and causing extensive silting. Mudslides are increasing in
frequency and scale. The flood risk is raised by the faster runoff. Aquifers are
becoming depleted because less water infiltrates to recharge them
Name three other ways in which people disrupt the drainage basin cycle - ANSWER:
Urban growth; constructing dams and reservoirs; abstracting water for irrigation
Distinguish between a water budget and a river regime - ANSWER: Water budget is
the difference between precipitation and evapotranspiration, which varies from
place to place and seasonally. River regime is the seasonal variation in the discharge
or flow of a river and it too varies, but from drainage basin to drainage basin
How does climate affect water budget? - ANSWER: It affects the amount of
precipitation received, while temperatures affect rates of evaporation and
transpiration
Identify three physical factors affecting a river's regime - ANSWER: Amount and
intensity of precipitation; geology and soils; vegetation cover
How do you explain the seasonal variations in runoff when rainfall is evenly
distributed throughout the year? - ANSWER: The lower runoff during the summer
and early autumn is due to the higher temperatures and high water losses due to
evapotranspiration. Also the dry ground means that much of the rain infiltrates and
percolates below ground
What is a storm hydrograph? - ANSWER: A storm hydrograph shows the response of
a river's discharge following a period of rainfall. A critical aspect of the hydrograph is
the lag time between the rainfall peak and the river's peak discharge
How does geology affect the shape of a storm hydrograph? - ANSWER: If the geology
is hard and impervious, then the speed of runoff will be such as to result in a
relatively short lag time. If the geology is soft and porous, then runoff will be less and
NEWEST 2024 ACTUAL EXAM COMPLETE 150
QUESTIONS AND CORRECT DETAILED ANSWERS
(VERIFIED ANSWERS) | VERIFIED ANSWERS
What is meant by a store and a flow? - ANSWER: A store is where water is held for
varying amounts of 'residence' time. A flow is the movement of water between
stores
Identify the three largest stores in size order - ANSWER: 1. The oceans
2. Icecaps and glaciers
3. Groundwater
Which two water stores are non-renewable, and why? - ANSWER: 1. Fossil water:
old, deep groundwater from former wetter periods
2. Losses from the cryosphere: melting of ice as a result of global warming
Distinguish between blue and green water - ANSWER: Blue water is stored in rivers,
lakes and groundwater in liquid form — a visible part of the hydrological cycle. Green
water is water stored in the soil and vegetation — an invisible part of the
hydrological cycle
Why is the hydrological cycle a closed system? - ANSWER: There are no external
inputs and outputs. It is a self-contained entity. Some might argue solar energy,
which drives the cycle, is an input
What is the water budget, and why does it vary from place to place? - ANSWER: The
water budget of a place is the difference between the amount of water gained from
precipitation and the amount lost as a result of evapotranspiration. The budget is in
surplus when precipitation exceeds evapotranspiration. It is in deficit when the
situation is reversed. It varies from place to place because climate (precipitation and
temperature) does
What are the main inputs of a drainage basin system? - ANSWER: Precipitation. Also
possibly water from a tributary basin
What are the main outputs of a drainage basin system? - ANSWER: Evaporation,
transpiration and river discharge
How does relief affect the inputs and outputs of a drainage basin? - ANSWER:
Altitude will affect the precipitation input (orographic rain or snow). The steepness
of slopes will affect the rate of runoff — the steeper the slope, the faster the rate
, Distinguish between interception and infiltration - ANSWER: Interception is the
process by which water is stored in the vegetation. Infiltration is the process by
which water soaks into, or is absorbed by the soil
How does geology affect the flows in a drainage basin? - ANSWER: Geology affects
the balance of the flows by which precipitation reaches a river. Where the geology is
hard and impermeable (e.g. granite), there will be much surface runoff and relatively
little infiltration and percolation. Where rock is porous, then the balance will be the
reverse with little runoff and much percolation and water reaching the river via
through flow and groundwater flow
Describe how deforestation is affecting the Amazon basin - ANSWER: The amount of
water returning to the atmosphere by evapotranspiration is greatly reduced — from
75% to 25% of intercepted water. More precipitation enters the river by runoff.
Overland flow increases the amount of soil erosion. Huge quantities of soil are
entering the rivers and causing extensive silting. Mudslides are increasing in
frequency and scale. The flood risk is raised by the faster runoff. Aquifers are
becoming depleted because less water infiltrates to recharge them
Name three other ways in which people disrupt the drainage basin cycle - ANSWER:
Urban growth; constructing dams and reservoirs; abstracting water for irrigation
Distinguish between a water budget and a river regime - ANSWER: Water budget is
the difference between precipitation and evapotranspiration, which varies from
place to place and seasonally. River regime is the seasonal variation in the discharge
or flow of a river and it too varies, but from drainage basin to drainage basin
How does climate affect water budget? - ANSWER: It affects the amount of
precipitation received, while temperatures affect rates of evaporation and
transpiration
Identify three physical factors affecting a river's regime - ANSWER: Amount and
intensity of precipitation; geology and soils; vegetation cover
How do you explain the seasonal variations in runoff when rainfall is evenly
distributed throughout the year? - ANSWER: The lower runoff during the summer
and early autumn is due to the higher temperatures and high water losses due to
evapotranspiration. Also the dry ground means that much of the rain infiltrates and
percolates below ground
What is a storm hydrograph? - ANSWER: A storm hydrograph shows the response of
a river's discharge following a period of rainfall. A critical aspect of the hydrograph is
the lag time between the rainfall peak and the river's peak discharge
How does geology affect the shape of a storm hydrograph? - ANSWER: If the geology
is hard and impervious, then the speed of runoff will be such as to result in a
relatively short lag time. If the geology is soft and porous, then runoff will be less and
