An open channel is a conduit in which water flows with a free surface. The free surface is subjected to atmospheric pressure. The classification of open channels is made based on different criteria as follows.

  • Classification Type 1
    1. Natural Channels
    2. Biya River

      Natural open channels include all channels that exist naturally on the earth. They are generally very irregular in shape.

      Example: Rivers, tidal estuaries, etc. 

    3. Artificial Channels
    4. Artificial open channels are the channels developed by men. They are usually designed with regular geometric shapes.

      Examples: Irrigation canals, laboratory flumes, spillway chutes, drops, culverts, roadside gutters, etc.

  • Classification Type 2
    1. Prismatic Channels
    2. A channel with an unvarying cross-section and a constant bottom slope is called a prismatic channel. All artificial channels are usually prismatic. The rectangular, trapezoid, parabola, and circle are the most commonly used shapes of prismatic channels.

    3. Non-prismatic Channels
    4. A channel with either a varying cross-section or a varying bottom slope is called a non-prismatic channel. The natural channels are usually prismatic. 

  • Classification Type 3
    1. Rigid Boundary Channels
    2. A concrete-lined irrigation canal brings water from Merritt Reservoir on the Niobrara River

      A channel with an immovable bed and sides is known as a rigid boundary channel.

      Example: Lined canals, sewers, and non-erodible unlined canals.

    3. Mobile Boundary Channels
    4. alluvial channel

      If a channel boundary is composed of loose sedimentary particles moving under the action of flowing water, the channel is called a mobile boundary channel.

      Example: An alluvial channel is a mobile boundary channel transporting the same type of material comprising the channel perimeter.

  • Classification Type 4
    1. Small Slope Channels
    2. An open channel having a bottom slope of less than 1 in 10 is called a channel of a small slope (Chow, 1959). The slopes of ordinary channels, natural or artificial, are far less than 1 in 10.

    3. Large Slope Channels
    4. An open channel having a bottom slope greater than 1 in 10 is called a channel of a small slope (Chow, 1959). Some artificial channels like drops and chutes have far more than 1 in 10.



Please note that the information in is designed to provide general information on the topics presented. The information provided should not be used as a substitute for professional services.