Surface Hydrology: Evaporation

Question 1

True or False
Soils include both a matrix and pores to allow water and air movement.

Answer 1

True

Question 2

The matrix in soils is composed of _______ and _______.

Answer 2

minerals, organic material

Question 3

Pore space in soil typically contains _______ and _______.

Answer 3

water, air

Question 4

What components are included in the equation for the earth’s surface energy balance?

Answer 4

Net radiation, sensible heat transfer, change in energy storage, energy exchange with the ground, and energy consumed by photosynthesis.

Question 5

What does the symbol 𝜆 represent in the earth surface energy balance equation?

Answer 5

Latent heat of vaporisation of water.

Question 6

What is the Bowen ratio and how is it calculated?

Answer 6

The Bowen ratio, 𝛽, is calculated as the ratio of sensible heat transfer (C) to the latent heat of vaporisation (𝜆E).

Question 7

What factors influence the magnitude of evaporation from open water surfaces?

Answer 7

Meteorological factors like solar radiation and wind speed, and physical factors such as salinity and water depth.

Question 8

True or False
Plants decrease the rate of water evaporation through interception.

Answer 8

False (they modulate water flows which can include increasing evaporation through processes like transpiration)

Question 9

Interception loss is calculated as precipitation minus _______ and _______.

Answer 9

throughfall, stemflow

Question 10

True or False
Cloud forests can experience negative interception, where throughfall and stem flow exceed precipitation.

Answer 10

True

Question 11

Potential evapotranspiration (E_p) occurs under _______ conditions when enough water is available.

Answer 11

optimal

Question 12

How does actual evapotranspiration differ from potential evapotranspiration?

Answer 12

Actual evapotranspiration may be lower than potential due to factors like water stress.

Question 13

What is reference evapotranspiration and how is it defined?

Answer 13

Reference evapotranspiration is the evapotranspiration rate of a sufficiently watered reference crop, used as a standard to estimate other rates of evapotranspiration.

Question 14

True or False
Stomata in plants enable CO2 uptake but do not contribute to water loss.

Answer 14

False

Question 15

Transpiration in plants depends on the number, size, and distribution of _______, among other factors.

Answer 15

stomata

Question 16

Which is NOT a factor that transpiration depends on?
A) Number of leaves
B) Solar radiation
C) Thickness of the epidermis

Answer 16

A) Number of leaves

Question 17

What method is commonly used for calculating the evapotranspiration rate 𝐸_𝑡 in plants?

Answer 17

The Penman-Monteith method.

Question 18

True or False
The Penman-Monteith method only uses one meteorological variable to determine energy availability.

Answer 18

False

Question 19

If a plant’s K_s value is 0, it will not _______ and will die.

Answer 19

transpire

Question 20

What instrument is typically used to measure stem flow in experiments?
A) Barometer
B) Water flow meter
C) Thermometer

Answer 20

B) Water flow meter

Question 21

True or False
Throughfall is measured using rain gauges installed above the canopy of a forest.

Answer 21

False (It is measured under the canopy)

Question 22

The complex value of 𝐸_𝑡 in lysimeter experiments is calculated by closing the water balance and weighing the total mass of _______.

Answer 22

volume

Question 23

The equation
E_t = (K_cK_sE_{t,0})×A is used to find E_t in what units?
A) Cubic meters
B) Liters
C) Kilograms

Answer 23

C) Kilograms

Question 24

What is K_s?

Answer 24

Thermal conductivity of the soil