It is the pattern formed by streams, rivers and lakes in a particular drainage basin. They are governed by topography of land, whether a particular region is dominated by hard or soft rocks, and gradient of the land.
MAIN TYPES OF DRAINAGE PATTERNS
Dendritic drainage pattern
It resembles branches of a tree. It develops in regions underlain by homogeneous material. That is, subsurface geology has a similar resistance to weathering so there is no apparent control over the direction the tributaries take. Tributaries joining larger streams at acute angle (less than 90 degrees). Ex. Rivers of northern plain & Godavari, Mahanadi, Kaveri, Krishna.
Trellis drainage patterns
When the primary tributaries of rivers flow parallel to each other and secondary tributaries the pattern is known as ‘trellis’. In this type of pattern, the short subsequent streams meet the mainstream at right angles, and differential erosion through soft rocks paves the way for tributaries. Ex. The old, folded mountains of Singhbhum (Chhotanagpur Plateau).
Rectangular patterns are produced by the right-angle bends in the main stream and the right-angle connections of the tributaries. These can be found in areas that have experienced faulting. It forms in areas with limited topography and a network of bedding planes, fractures, or faults that is shaped like a rectangle. Ex: Streams found in Vindhyan Mountains of India.
Parallel drainage pattern
It comprises numerous rivers which are parallel to each other and follow the regional slope. This pattern is more frequently developed on uniformly sloping and dipping rock beds such as newly emerged coastal plains. Ex. Small rivers from Western Ghats that flow into the Arabian Sea and Rivers of the lesser Himalayas.
Radial drainage pattern
When the rivers originate from a hill and flow in all directions, the drainage pattern is known as ‘radial’. The rivers originating from the Amarkantak range present a good example of it. Rivers like Narmada, Son and Mahanadi originating from Amarkantak Hills flow in different directions and are good examples of radial pattern.
Centripetal drainage pattern
When rivers discharge their waters from all directions in a lake or depression, the pattern is known as ‘centripetal’. Ex. Sambhar basin has a centripetal drainage pattern as streams drain towards the lake. It is mainly fed by four streams namely Mendha, Rupangarh, Kharain and Khandel.
Deranged drainage pattern
It is a drainage system in drainage basins where there is no coherent pattern to the rivers and lakes. It happens in areas where there has been much geological disruption. Ex. A classic example is the Canadian Shield. During the last ice age, the topsoil was scraped off, leaving mostly bare rock.
Inland drainage system: In this, river do not drain into an ocean or sea but they drain into a lake or in an inland sea.
- Ex. (i) Ghaggar river is a seasonal river that flows through Haryana, Punjab and Rajasthan in north-western India. It is an important water resource for the region and its tributaries provide water for irrigation and drinking. It is also important for its archaeological value, as it is believed to be the ancient Sarasvati River, mentioned in the ancient Indian texts.
- (ii) Luni River is a seasonal river that flows through the states of Rajasthan and Gujarat in north-western India. It originates in the Aravalli Range and empties into the Rann of Kutch in Gujarat.
- Both rivers are examples of inland drainage systems in India, as they do not have natural outlets to the sea and their water is collected and transported through a network of channels and canals to prevent flooding and manage water resources in the region.