Stages of Stream Development

The formation of a stream valley is a long process. Each stage occurs in different locations and features specific characteristics. The aging process of a stream valley has three stages, including youth, maturity, and old age.

YOUTH STAGE

A stream is said to be youth stage when it cuts its valley downwards to establish a graded condition with its base level.

a. Position: commonly found in mountains from where a stream starts its journey.

b. Erosion: down cutting is dominant.

c. Valley Shape: narrow and V- shaped.

d. Longitudinal Profile: the gradient is steep (ungraded). Waterfalls and rapids are common.

e. Valley Floor: the stream occupies most of the width of valley floor as result there is little or no floodplain.

f. Stream Pattern: is angular and without meanders, tributaries are short and few.

MATURE STAGE

A stream is set to be in mature stage when downwards erosion diminishes and lateral erosion dominates.

a. Position: commonly found in the plains lying adjacent to the mountain region.

b. Erosion: down cutting diminishes and tide cutting dominates.

c. Valley Shape: broad and trough shaped.

d. Longitudinal Profile: the gradient is moderate. Water falls and rapids are absent. Valley bottom is graded so that longitudinal profile exhibits a relatively smooth curve.

e. Valley Floor: 
f. Stream Pattern: 

OLD STAGE

A stream is said to be in old stage, when the flood plane of stream becomes several times wider than its meander belt.

a. Position: found near mouth of stream.

b. Erosion: the stream ceases to enlarge the floodplain. The main work of a stream story work the encounter solidated sediment of floodplain.

c. Valley Shape: wide and open with less boundaries, which may be indistinct.

d. Longitudinal Profile: the gradients become very low. The stream approaches base level and it aggrades strongly.

e. Valley Floor: oxbow lakes are common. Natural embankment are also present. They are accompanied by back swamps and yazoo tributaries.

f. Stream Pattern: is meandering with oxbow lakes. Tributaries are few and large.

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