Shape of a River - Geomorphology
Streams express their energy by the formation of
meanders and by adjusting their slope. This
fact is most obvious where streams flow over beds
of unconsolidated sediment. Streambeds composed
largely of bedrock prevent or inhibit the
expression of these features.
Meanders develop according to fairly consistent
patterns, regardless of stream size. Bends form,
alternating right to left, with a radius about two
to four times stream width. Vary the scale, and an
aerial photograph of a small creek would resemble
the pattern of a large river.
As streams continue to cut against the outside
of the stream bank, they accentuate the bend. Many
meanders eventually break through, allowing the
flow to shortcut the meander. The abandoned meander
is called an oxbow.