Week 6: Evapotranspiration, Thresholds and Water Balance Approach

Question 1

Evaporation (E)

Answer 1

A collective term for the transfer of water, as water vapour, to the atmosphere from unvegetated land surfaces.

Question 2

Transpiration (T)

Answer 2

Water lost by evaporation through the stomata of plants.

Question 3

Vapour pressure deficit (VPD)

Answer 3

The difference between the amount of moisture in the air and how much moisture the air can hold when it is saturated.

Question 4

Saturation vapour pressure

Answer 4

When air reaches the saturation vapour pressure the water vapour in it will condense, forming clouds.

Question 5

Lysimeter

Answer 5

A measuring device which can be used to measure the amount of actual evapotranspiration (ET) which is released by a plant.

Question 6

Aerodynamic conductance

Answer 6

The intensity of the near-surface vertical turbulence that transports heat and moisture between the land surface and overlying atmosphere.

Question 7

Threshold storage

Answer 7

The magnitude or intensity that must be exceeded for a certain reaction, result or condition to occur. e.g. a river to flood.

Question 8

Change in storage

Answer 8

The change in the amount of water held in a system at a given point in time.

Question 9

Storage capacity

Answer 9

The range of available water that can be stored in soil.

Question 10

Non-linearity in response

Answer 10

Involving a lack of linearity in the relationship between two quantities such as input and output.