31.3.4. Horton's Infiltration Index

Try these first

1. 1.

   What does the decay constant (k) represent in Horton's equation?

   Hint

   Think about what happens to infiltration capacity after rain starts.

2. 2.

   Explain how Horton's equation can be used to manage irrigation practices.

   Hint

   Consider the importance of knowing when soil reaches saturation.

3. 3.

   What does the decay constant (k) signify in Horton’s equation?

   Hint

   Consider its role in infiltration behavior over time.

4. 4.

   Horton’s Infiltration Index is primarily used to estimate:

   • Initial runoff volume
   • Average infiltration rates
   • Soil moisture levels

   Hint

   Think about what the index aims to simplify in hydrologic analysis.

5. 5.

   If f0=15 mm/hr and fc=3 mm/hr, given k=0.3, what would the infiltration rate be after 5 hours?

   Hint

   Calculate e^{-1.5} first to find the rate.

6. 6.

   Discuss the implications of using only the initial infiltration capacity when applying Horton's Index in urban planning.

   Hint

   Consider why urban areas require precise rainfall runoff predictions.