26.6.2. Philip’s Equation

Try these first

1. 1.

   What does the variable 'S' represent in Philip’s Equation?

   Hint

   Think about the soil characteristics that allow water to penetrate.

2. 2.

   Define steady infiltration rate (A) in the context of Philip’s Equation.

   Hint

   Consider how gravity affects water movement in soil.

3. 3.

   What does Philip’s Equation help to calculate?

   • Surface runoff
   • Infiltration rate
   • Soil erosion

   Hint

   Focus on what the equation is primarily representing.

4. 4.

   True or False: Sorptivity increases with soil moisture.

   • True
   • False

   Hint

   Think about how saturation affects absorption.

5. 5.

   If a farmer knows that his soil has a sorptivity of 4 cm/hr^(1/2) and a steady infiltration rate of 6 cm/hr, what will be the infiltration rate after 9 hours?

   Hint

   Evaluate the inverse of time carefully.

6. 6.

   Discuss how you would adjust irrigation practices on a property with varying soil types from sandy to clayey. Include how Philip's Equation would guide your decisions.

   Hint

   Think about how each soil's characteristics affect water management.