DRAINAGE
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The term "drainage" describes the river system of an area.
The area by a single river system is called a "drainage basin" or river basin.
Any higher ground, such as mountain or upland separates two adjoining drainage basins. Such
upland is known as a water divide or a watershed.
DRAINAGE PATTERN:
The streams within a drainage basin form certain patterns, depending on the slope of land, underlying
rock structure as well as the climate condition of the area.
They are four types:
 Dendritic Drainage.
 Rectangular Drainage.
 Trellis
 Radial Drainage.
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Dendritic Drainage:
The dentritic pattern develops where the river channel follows the slope of the terrain.The
stream with its tributaries resembles the branches of a tree, thus it is named dentritic.
Rectangular drainage:
The rivers which are parallel to each other and follow the regional slope. This pattern is
developed on uniformly sloping areas such as coastal plains.
Trellis Drainage:
In this system the tributaries can be seen meeting the main stream at right angles.This exists
where hard and soft rocks exist parallel to each other.
Radial Drainage:
It develops where streams flow in different directions from a central peak or dome like structure.
Streams which diverge from a central higher point in all directions.
ORAL QUESTIONS:
1.
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3.
4.
5.
What is Drainage?
Define Drainage Basin?
What is called a Water Divide?
Give one example of Drainage Basin?
What is Radial Drainage Pattern?
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Drainage System of India
On the Basin of origin, two broad drainage systems of India are generally recognized.
The Himalayan Rivers & the Peninsular Rivers.
Apart from originating from the two major physiographic regions of India, the Himalayan and the
Peninsular Rivers are different from each other in many ways.
A COMPARATIVE STUDY
Himalayan Rivers:
Peninsular Rivers:
1. Originate from lofty ranges of the Himalaya.
1. Originate in the peninsular Plateau.
2. Large basins and catchment area.
2. Small basins and catchment areas.
3. Form deep I-Shaped valleys called Gorges.
3. Flow in comparatively shallow valleys.
4. Perennial, water flows throughout the year.
4. Seasonal rivers as they are rainfed, water
flows mostly in rainy season.
5. Are in a youthful age.
5. Mature Rivers.
6. Rivers form meanders and often shift their
6. Flow more or less straight course and do
courses.
not form meanders.
7. Form big deltas at their mouth.
7. Form smaller deltas, and estuaries.
MULTIPLE CHOICE QUESTIONS:
1. The area drained by a single river system is called a
a) Drainage
b) Drainage basin
c) River system d) River Divide.
2. An elevated area, separating two drainage basin is known as
a) Water joint.
b) water Divide
b) Drainage pattern. d) Drainage basin.
3. What is the most important characteristic of the Himalayan River?
a) Seasonal b) Rainy Season
c) Perennial d) None of these
PROJECT WORK:
1) Make a list of major rivers of India and mark and label them in an outline of India.