39.9. Canal Design Based on Duty

Try these first

1. 1.

   Define duty in your own words.

   Hint

   Think about how much land can be watered by one 'unit' of water.

2. 2.

   What does delta represent?

   Hint

   Consider how much water a plant needs from sowing to harvest.

3. 3.

   What is duty in irrigation?

   • Area per water unit
   • Total water requirement
   • Length of canal

   Hint

   Think about how we measure water use efficiency.

4. 4.

   True or False: Delta indicates the total depth of water crops need during their growth phase.

   • True
   • False

   Hint

   Reflect on what crops need for optimal growth.

5. 5.

   Design an irrigation system for a region with highly variable rainfall. Discuss how you would calculate required duty and delta and justify your design choices.

   Hint

   Use historical data to balance crop needs with fluctuating water availability.

6. 6.

   Evaluate an existing irrigation canal's performance based on its measured discharge against the designed duty and delta. What recommendations would you make?

   Hint

   Reflect on common issues like seepage and evaporation losses.