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River Basin & Stream - Types, Patterns #10x_simple

Catchment/Basin,
Stream Types,
Stream Patterns,
Channel Pattern,
Descriptions of Basins,

Stream Types:

Permanent Streams: Streams which flow throughout the year.
Intermittent streams: Streams whose sources of water periodically fails, can be spring-fed or surface-fed.
Ephemeral streams: Streams which flow only in response to precipitation.
Consequent streams: streams that follow certain courses as a result of initial depressions in land or slopes that antedated the stream.

Subsequent streams: Streams which cut through the uptilted beds in folded regions.

Obsequent streams: Streams which have developed in certain positions by adjustment to rock structure.

Antecedent streams: Streams which retain its course despite obstructions provided by geological processes.

Stream Patterns
From its source, a river flows downhill.
This is because of the Earth’s gravity.
Small trickles of water join up to form a stream.
The amount of water in the stream increases steadily as more streams, called tributaries.
Join it and eventually the stream becomes big enough to be a river.
A drainage basin is the land that supplies water to the river and its tributaries.
If you could look down on a river from above, you would see its branches.
This is called a drainage pattern.

Dendritic: Dendritic patterns are the random orientation of channels that spread like tree.

Trellis: In a trellis pattern primary tributaries join main streams at right angle and the secondary tributaries parallel to the main streams.

Radial: Radial drainage patterns develop in isolated topographic uplands that flow outward from center of their origin.
Volcanoes and domes may display this pattern.

Parallel and Sub-parallel: Parallel drainage patterns occur in the same type of rocks to a steeper slope.
A different type of pattern occurs when the rock units are arranged in parallel bands of alternating weak and strong lithologies.

Rectangular: Rectangular drainage pattern form a perpendicular net with the two directions equally developed where faults or joints are the main controlling factors.
These channels are the characteristics of rocks of uniform resistance cut by perpendicular joint sets.