Irrigation Training Manual: Planning, Design, Operation and Management of Small-Scale Irrigation Systems (Peace Corps, 1994, 151 p.)
 Training session
 Section 4: Developing water sources
 (introduction...) Exam: Section 4 - Developing water sources

### Exam: Section 4 - Developing water sources

1. List different types of material that can be used to construct a diversion.

 earth sand bags rocks gabions logs concrete

2. Describe what a gabion is and explain how it can be used in diversion dams.

A gabion is a basket made of heavy-duty wire mesh, placed in the stream bed, and filled with rock. It is used as a building block in construction of diversions.

3. Describe the sequential steps in developing a spring source.

1. Locate the origin of the flow.
2. Dig large hole.
3. Measure the flow from the spring.
4. Fill in the hole with gravel or rocks to protect spring.
5. Dig diversion ditch above spring.

4. Explain the situations in which you would consider a hand-dug well for irrigation; a commercially drilled well.

Hand-dug - Shallow water table, low flow rate required, labor is cheap and available.

Drilled - Deep water tables, hard formations such as rock, larger flow rates required, availability of equipment or commercial well drillers.

5. A farmer comes to you and asks for advice on a secondhand, 5 HP, centrifugal pump that he has just bought. He wants to sprinkler irrigate a 0.5 hectare plot but knows nothing about the pump capacity. What factors must be taken into consideration?

1. What flow rate is required?

6. Describe the equation needed to calculate total dynamic head in a pumping system. (Assume velocity head is negligible.)

tdh = hz + hp + hf

hz = elevation head (vertical distance pump must raise water)
hp = pressure head (pressure required to operate the sprinkler system, drip system, etc.)
hf = friction head (pressure losses due to flow through pipe)

7. List the general specifications that you should provide a pump supplier when selecting a pump.

- amount of water to be pumped