Water Resources

Question 1

True/False
Water Resources Management includes calculating both hydropower and irrigation water demand.

Answer 1

True

Question 2

Agriculture consumes about ___% of global blue water withdrawals.

Answer 2

70%

Question 3

What proportion of global food is produced in artificially irrigated areas?

Answer 3

40 %

Question 4

Water stress → __
Water scarcity → __

Answer 4

• Demand exceeds supply or poor quality limits use
• Annual supply < 1000 m³ per person

Question 5

An annual supply < ___ m³/person is water stress
< ___ m³/person is water scarcity.

Answer 5

1700
1000

Question 6

What is virtual water?

Answer 6

The water used in the production of goods or services

Question 7

Green water → __
Blue water → __
Grey water → __

Answer 7

Rainwater evaporated
Surface/groundwater evaporated
Polluted water volume

Question 8

List three major uses of water in human activities.

Answer 8

Domestic, Irrigation, Industrial (plus Commercial, Mining, Thermoelectric, etc.)

Question 9

Hydropower equation:

Answer 9

P = εₜ εg ρ g h Q
Where P = power, ε = efficiencies, h = head, Q = flow

Question 10

Runoff Ratio (RR) = __

Answer 10

RR = R̄ / P̄ (average runoff / average precipitation)

Question 11

Formula
Irrigation requirement:

Answer 11

I = Ep − P + R

Question 12

Irrigation Water Demand
Ks = 1 →
Et = Ep →

Answer 12

• Optimal growing conditions
• No water stress

Question 13

Kc depends on:

Crop type → __
Climate → __
Soil → __

Answer 13

• Albedo, height, stomata
• Wind, humidity
• Planting density

Question 14

Kc values vary by growth stage: Initial, Development, ____, ____

Answer 14

Mid-season, Late-season

Question 15

True/False
Kc values are fixed across crop life cycle.

Answer 15

False (they vary by stage)

Question 16

Formla
Total Available Water (TAW):

Answer 16

TAW = (θFC − θWP) × Zr
θₓfc = Volumetric water content at field capacity
θₓwp = Volumetric water content at wilting point
Zᵣ = Root depth

Question 17

Field Capacity (FC) = suction of __
Wilting Point (WP) = suction of __

Answer 17

• −0.33 bar
• 15 bar

Question 18

Formula
RAW =

Answer 18

p × TAW
RAW = Readily Available Water (mm or m³/m²)
p = Depletion factor (dimensionless, crop-specific; e.g. 0.3–0.7)
TAW = Total Available Water (mm or m³/m²)

Question 19

True/False
Applying water above RAW reduces stress without losses

Answer 19

False (can cause seepage losses)

Question 20

List two surface irrigation types.

Answer 20

Basin, furrow (others: flood, border-strip, etc.)

Question 21

Sprinkler irrigation → __
Micro-irrigation → __

Answer 21

• Simulates rainfall
• Drip/trickle systems

Question 22

True/False
Drip irrigation reduces salinisation risk.

Answer 22

False (it increases salinisation due to evaporation)

Question 23

Key human drivers of hydrological change include: urbanisation, agriculture, forestry, and ______.

Answer 23

climate change

Question 24

True/False
Forests reduce water runoff and stabilise catchment hydrology.

Answer 24

True

Question 25

What is the principle of natural flood management?

Answer 25

Using natural processes to reduce flood risk, such as restoring wetlands or reforesting catchments.

Question 26

What is "water sowing and harvesting"?

Answer 26

Traditional methods to store water in landscapes, especially in high-altitude Andean regions.

Question 27

What are greenhouse gases?

Answer 27

Gases that absorb and re-emit longwave radiation, warming the atmosphere.

Question 28

True/False Greenhouse gases block both longwave and shortwave radiation

Answer 28

False (transparent to shortwave, absorb longwave)

Question 29

Formula Boltzmann Law:

Answer 29

F = εσT⁴ Where F = radiated energy, T = temperature, ε = emissivity, σ = Boltzmann constant

Question 30

Formula Wien’s Law:

Answer 30

λmax = 2897 × 10⁻⁶ / T

Question 31

Sun temperature → Earth temperature →

Answer 31

- shortwave radiation - longwave radiation

Question 32

What do GCMs simulate?

Answer 32

The global climate system and hydrological exchanges of energy and water.

Question 33

True/False GCMs only simulate atmospheric processes

Answer 33

False (they include ocean, land, hydrology, etc.)

Question 34

Projecting climate change requires assumptions about ______ scenarios.

Answer 34

socio-economic

Question 35

True/False Climate models can reproduce current temperature trends using only natural forcings.

Answer 35

False

Question 36

Hydrological Processes in GCMs Evapotranspiration modelled with → __ UK Met Office model → __

Answer 36

- Penman-Monteith - MOSES land surface model in HadCM3

Question 37

What is the spatial resolution of the HadCM3 atmospheric model?

Answer 37

~417 km × 278 km (too coarse for most catchments)

Question 38

To use GCMs locally, projections must be _______.

Answer 38

downscaled

Question 39

True/False Downscaling adds certainty to model outputs.

Answer 39

False (it introduces new uncertainties)

Question 40

Why is there often a mismatch between GCMs and hydrological needs?

Answer 40

Because GCM resolution is too large to capture local hydrological processes.

Question 41

Name two local hydrological impacts of climate change.

Answer 41

Changes in river flow, shifts in seasonal runoff patterns

Question 42

True/False GCMs are accurate enough to directly assess water risks in small catchments

Answer 42

False