43.1.5. Infiltration Indices

Try these first

1. 1.

   Define the ϕ-index in one sentence.

   Hint

   Think about how it relates to rainfall and runoff.

2. 2.

   What does W-index measure?

   Hint

   Consider what happens during a rain event.

3. 3.

   What is the primary purpose of the ϕ-index?

   • To measure soil texture
   • To predict runoff volume
   • To calculate evaporation rates

   Hint

   Focus on the role of the ϕ-index in water movement.

4. 4.

   Is the W-index used to measure infiltration that occurs after runoff begins?

   • True
   • False

   Hint

   Think about what happens at the beginning of rainfall.

5. 5.

   A study site has an initial infiltration rate of 20 mm/hr and a final rate of 5 mm/hr with a decay constant of 0.08. Calculate the infiltration rate after 5 hours using Horton's Equation.

   Hint

   Remember to use the decay constant and exponentiate correctly.

6. 6.

   Analyze how changes in land use from agricultural to urban can affect the values of the ϕ-index and W-index in the context of runoff management.

   Hint

   Think about the nature of the surfaces and the direction of water.