March 1, 2017

Habitat Type Classification

Habitat types represent the classic hydrologic units of pool, riffle or run. Visual classification of habitat type was performed from the high definition video for the left, center, and right banks views of the river.

  • Pools are the deepest locations of the reach. Water surface slope of pools at baseflow is near zero. Pools are often located at the outside of meander bends. Visually, pools have smooth surfaces without obvious current present.

  • Riffles are the sections of the bed with the steepest slopes and shallowest depths at flows below bankfull. Riffles typically occur at the crossover locations and have a poorly defined thalweg. Visually, riffles are defined as areas with broken surface flows (whitewater).

  • Runs differ from riffles in that depth of flow is typically greater and slope of the bed is less than that of riffles. Runs will often have a well-defined thalweg. Visually, runs are areas without broken surface flows but with obvious current present.

  • Other, additional categories could be added to account for specific conditions such as drops, hydraulic jumps, or man-made constrained channels.