Large Drainage Basin

Large Drainage Basin

An extent of land that occurs naturally for the purpose of draining or channeling excess precipitation water to a river is what is known as a drainage basin. Many other terms are used to describe a large drainage basin such as water basins, river basins, watersheds or catchment basins.

Sometimes, large drainage basins occur in nature adjacent to or near each other and in such cases are divided by geographical boundaries such as mountains or hills. Due to these divisions in nature between drainage basins, the direction of water flow is regulated and influenced. There are many other factors that determine the content of the water in the basin as well as the nature of movement of its flow. Some of them are:

  • The landscape of the area where the drainage basin is located.
  • The weather conditions of that area.
  • The type of soil that is predominantly prevalent in those regions.
  • The type of plant life that grows in the geographical location.

How Does a Drainage Basin Work?

Once a large drainage basin is formed in a particular area it can assume one among various patterns. Most of these patterns are easily recognizable from aerial views for plotting on a map. More often,  smaller basins known as a sub-drainage come together and make a large one. While the water drained from the former join streams, the large basins contribute water to larger bodies such as rivers.

Water from melted ice or snow, rain and other such sources tend to collect in a large drainage basin and converge to a point at its base or exit, from where the water is then drained to join other water bodies. The drained water may join a river, reservoir, sea or ocean depending on the geographical location. Therefore, a drainage basin may be compared to a funnel in terms of the way it functions.

Sometimes, in a closed drainage basin, once the water converges or collects at the single point, it can form a lake right there or the water could just be lost underground.

Large Drainage Basin Patterns

There are different types of large drainage basins depending on the patterns that they form during the flow and draining of water. For instance, when a basin is located around a hill or any such high, central point, the flow of water tends to take a radial pattern. Such a basin is termed as a radial drainage basin. In other rocky regions, there are several other patterns that can be assumed. If the flow of water is uni-directional, parallel patterns tend to form. In other cases, fault lines, joints and other types of fractures in the rocks causes the patterns to be rectangular or in right angles.

In areas where the terrain has been recently formed such as places where natural calamities have occurred, deranged drainage basin patterns are found. This is due to the formation of water pockets in bends and streams.

A lot can be studied and researched about large drainage basins with the help of various websites, maps and books on geography.



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