POOL/GLIDE AND RIFFLE/RUN QUALITY METRIC:

This metric describes the characteristics of areas with the slowest and fastest currents.

Pools and glides are areas of slow current. Both are typically bowl-shaped features in the stream bed, and they are often the areas of greatest stream width. Pools do not show much, if any current at the surface; glides show slow steady movement.

Riffles and runs are areas of rapid and turbulent movement. Riffles are typically fairly shallow and show the most turbulent movement in the stream, where the water moves over rocks or uneven bedrock bottom. Runs may be deeper and show turbulent flow over an uneven bottom.

RIFFLE/ RUN DEPTH

Refers to the riffles (areas of fast current velocity, shallow depth, and broken water surface) and runs (areas of rapid non-turbulent flow).

• The following Riffle/Run Depths are included in the QHEI Pool/Glide And Riffle/Run Quality metric:
• Generally Greater than 10 cm, Max Greater than 50 cm.
• Generally Greater Than 10 cm; Max Less Than 50
• Generally 5 - 10 cm
• Generally Less Than 5 cm (Riffle Absent)

Generally Greater than 10 cm, Max Greater than 50 cm. [4] The riffle is generally deeper than 10 cm, and the maximum depth of the riffle areas is greater than 50 cm. Riffle/Run Depths QHEI Metrics NORP Main Menu

Generally Greater Than 10 cm; Max Less Than 50 [3] The riffle is generally deeper than 10 cm, but the maximum depth of the riffle areas is shallower than 50 cm. Riffle/Run Depths QHEI Metrics NORP Main Menu

Generally 5 - 10 cm [1] The depth of the riffle is generally between 5 and 10 cm. Riffle/Run Depths QHEI Metrics NORP Main Menu

Generally Less Than 5 cm (Riffle Absent) [0] The depth of the riffle is generally less than 5 cm (2 inches). When this is the case, the riffle is not forming a suitable habitat for living organisms, and it should not be considered to constitute a riffle. Riffle/Run Depths QHEI Metrics NORP Main Menu