Enter the total length of all streams and rivers (miles) and the total area of the drainage basis (square miles) into the Drainage Density Calculator. The calculator will evaluate and display the Drainage Density. 

Drainage Density Formula

The following formula is used to calculate the Drainage Density. 

DD = RL /  BA

  • Where DD is the Drainage Density (1/miles)
  • RL is the total length of all streams and rivers (miles) 
  • BA is the total area of the drainage basis (square miles) 

How to Calculate Drainage Density?

The following example problems outline how to calculate Drainage Density.

Example Problem #1:

  1. First, determine the total length of all streams and rivers (miles). 
    1. The total length of all streams and rivers (miles) is given as: 500.
  2. Next, determine the total area of the drainage basis (square miles). 
    1. The total area of the drainage basis (square miles) is provided as: 1500.
  3. Finally, calculate the Drainage Density using the equation above: 

DD = RL /  BA

The values given above are inserted into the equation below:

DD = 500 /  1500 = .333 (1/miles)

Example Problem #2: 

For this problem, the variables needed are provided below:

total length of all streams and rivers (miles) = 23050

total area of the drainage basis (square miles) = 2020

This example problem is a test of your knowledge on the subject. Use the calculator above to check your answer. 

DD = RL /  BA = ?