2. SCS Curve Number SCS CN Method

Try these first

1. 1.

   What does SCS stand for?

   Hint

   Think of the agency responsible for the method.

2. 2.

   Is higher Curve Number associated with more or less runoff?

   Hint

   Consider what the number represents regarding infiltration.

3. 3.

   What is the range of Curve Numbers?

   • 0-100
   • 30-100
   • 50-90

   Hint

   Remember that higher numbers indicate less infiltration.

4. 4.

   True or False: Initial Abstraction is always equal to 0.2 times S.

   • True
   • False

   Hint

   Think about how you're estimating runoff and its components.

5. 5.

   You have a watershed with a Curve Number of 75 and a rainfall event of 80 mm. Calculate the expected runoff if the initial abstraction is 0.2S. Make assumptions for S.

   Hint

   Use the curve number to find S.

6. 6.

   If an area changes from agricultural to urban use, how would that affect the Curve Number and runoff potential? Discuss the implications.

   Hint

   Consider permeability of surfaces.