26.5. Infiltration Indices

Try these first

1. 1.

   What does the φ-index represent?

   Hint

   Think of it as an infiltration threshold.

2. 2.

   Name one purpose of the W-index.

   Hint

   Consider initial conditions before a storm.

3. 3.

   What does the φ-index represent?

   • Initial infiltration rate
   • Minimum infiltration rate
   • Threshold above which runoff occurs

   Hint

   It is about the runoff threshold.

4. 4.

   The W-index accounts for initial moisture loss during what?

   • True
   • False

   Hint

   Think about conditions before a rainfall event.

5. 5.

   Calculate the runoff for a rainfall event of 12 mm/hr when the φ-index is 7 mm/hr.

   Hint

   Remember the formula for calculating runoff.

6. 6.

   How can seasonal changes in soil moisture impact the use of the W-index for modeling?

   Hint

   Think about soil conditions throughout the year.