FLOOD02106

• County: Statewide
• Community: State of Colorado
• Stream Name: All
• Title: Stream Stability and Scour at Highway Bridges Participant Workbook
• Date: 10/1/1999
• Prepared For: Students
• Prepared By: Federal Highway Administration
• Floodplain - Doc Type: Educational/Technical/Reference Information

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RIVER CHANNEl PATTE:RNS

c. Meandering streams

A meanderin!~ channel consists of pools and crossings, with
the thalweg (deepest point in the cross section where the
main current is flowing) flowing from pool to pool through the
crossings in an S-shaped a1i!~nment.

The degree of meandering is described by sinuosity, de1ined
as the ratio of the thalwe~l distance to valley distance.
Straight channels have a sinuosity of one. There is no direct
relationship between the dElgree of sinuosity and lateral
instability (see Item g below),

For a meandering stream, erosion generally attacl<s the
outside of the meander bend. Deposvtion occurs on the
point bar on the inside of the bend. The position of the main
current (thalweg) changes from low flow to high flow,

Formation of cutoffs and oxbow lakes.

2.11