Drainage Density Calculator

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. 

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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) 

To calculate the drainage density, divide the total length of all streams by the total area of the drainage basis.

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)

FAQ

What factors can affect Drainage Density?

Drainage Density can be influenced by several factors including the type of soil, vegetation cover, climate, topography, and human activities. For example, areas with impermeable soil, sparse vegetation, and steep slopes tend to have higher drainage densities due to faster surface runoff.

Why is understanding Drainage Density important?

Understanding Drainage Density is crucial for hydrological studies, flood management, and urban planning. It helps in assessing the potential for flooding, designing efficient drainage systems, and managing water resources in both rural and urban areas.

How can changes in land use affect Drainage Density?

Changes in land use, such as deforestation, urbanization, and agricultural development, can significantly affect Drainage Density. For instance, urbanization increases impervious surfaces, leading to higher runoff and potentially higher drainage density, which can increase the risk of flooding.