39.2.3. Units

Try these first

1. 1.

   Define Duty in the context of irrigation.

   Hint

   Think about how land area relates to water flow.

2. 2.

   What is Delta?

   Hint

   Consider the time frame from sowing to harvesting.

3. 3.

   What is Duty in irrigation design?

   • The depth of water required
   • Area irrigated per unit discharge
   • Type of soil

   Hint

   Consider the relationship between area and water flow.

4. 4.

   True or False: Delta is measured at the head of the canal.

   • True
   • False

   Hint

   Think about what Delta actually represents.

5. 5.

   If an irrigation canal has a discharge of 15 cumecs and irrigates a total of 37,500 hectares, calculate the Duty. If the base period is 150 days, find the Delta.

   Hint

   Break the problem into two parts: first calculate Duty, then use that to find Delta.

6. 6.

   An irrigation project requires that 1000 hectares needs a total of 80 cm of water over 120 days. What should be the capacity (in cumecs) of the irrigation system?

   Hint

   Convert water depth to meters and apply the Delta formula in reverse.