L33-35: Water Harvesting

Question 1

Water harvesting:

Answer 1

collection and concentration of precipitation for productive use

Question 2

Rainwater harvesting

Answer 2

• capture run-off from roof or ground surfaces

Question 3

Floodwater harvesting

Answer 3

• capture discharge from water course

Question 4

Types of water harvesting for plant production:

Answer 4

• microcatchments (RWH)
• external catchments (RWH)
• floodwater farming (FWH)

Question 5

Microcatchments:

Answer 5

overland flow harvested from short catchment length (1-30m) and stored in soil profile.

• no provision for overflow
• even plant growth
• Ca:C ratio 1:1 to 3:1

Question 6

External Catchments

Answer 6

Overland flow or rill flow with catchment length 30-200m. Runoff stored in profile.

• provision for overflow
• uneven plant growth (unless leveled)
• Ca:C ratio 2:1 to 10:1

Question 7

Floodwater farming:

Answer 7

Turbulent channel flow (diverted or spread with channel bed) with long catchment. Runoff stored in soil profile.

• provision for overflow
• Ca:C ration > 10:1