Drainage system

From ArticleWorld


A Drainage system is the term used to define an integrated network formed by a main river and its many tributaries which collect and channel surface water to the sea, a lake, or some other body of water. This system is to a large extent dependent on the lay (the gradient) of the land as well as its topography. If the topography constitutes hard rocks the drainage system will be of a pattern that is different from the pattern that is formed by soft rocks.

[edit]

Kinds of drainage

There are many different kinds of natural drainage systems. Some of the more important ones are:

  1. Dendritic drainage system: This consists of the main river which appears like a main trunk fed from a variety of branches (tributaries) which turn are fed by their tributaries so that the end result resembles the veins on a leaf. Main examples of such systems would be the Amazon River with its tributaries, The Mississippi and the Ganges.
  2. Parallel drainage system: This system forms in steep mountainous regions where streams run parallel to instead of joining each other due to the sharp gradient.
  3. Trellis drainage system: This type of formation occurs when streams run parallel to each other but they are also joined by minor tributaries at right angles.
  4. Radial drainage system: This system resembles a wheel with spokes, the high point (generally a hill or a mountain) of the region forming the hub of the wheel and the rivers draining away from it like spokes from the hub. Mt. Taranaki (on the west coast of New Zealand’s North Island) with its rivers is a good example of such a drainage system.
  5. Deranged drainage system: When there is no rational and consistent drainage system of rivers and lakes but seems to be a mixture of many the drainage system becomes deranged. This happens when there has been violent geological activity in a region. A good example of such a system is the Canadian Shield where the irregular land has given rise to many lakes and the drainage system is still not mature enough to conform to a particular type.
Retrieved from "http://www.articleworld.org/index.php/Drainage_system"