39.1.2. Mathematical Expression

Try these first

1. 1.

   Define Delta in the context of irrigation.

   Hint

   Think about what water needs a crop has.

2. 2.

   What is the formula for Duty?

   Hint

   Remember Duty relates area and discharge.

3. 3.

   What is Delta defined as?

   • Total area of land irrigated
   • Total depth of water required by a crop
   • Flow rate of water

   Hint

   Consider what we defined Delta as.

4. 4.

   True or False: Duty is dependent only on crop type.

   • True
   • False

   Hint

   Think about what else affects irrigation.

5. 5.

   You have a canal that irrigates 10,000 hectares with a discharge of 5 cumecs. Calculate the Duty and determine the required Delta for a base period of 150 days.

   Hint

   Follow the formula for both Duty and Delta to solve.

6. 6.

   Evaluate how changing from a flood irrigation system to a drip system could improve Duty for a cotton crop.

   Hint

   Consider the efficiency of different irrigation methods.