Amarkantak plateau

Topic: Drainage System of India: Rivers, Basins and Patterns · NCERT: Class 11, Ch 3 "Drainage System"; Class 11, Ch 5 "Natural Vegetation"

Meaning

The Amarkantak plateau is a high, flat-topped upland in the Maikal (Maikala) range on the Madhya Pradesh–Chhattisgarh border. The Narmada and the Son rise here, and streams of the Mahanadi system start on its eastern and southern slopes. Because rivers flow outward from it in different directions, it is India's best-known example of a radial drainage pattern. It is also a "water tower" for several states, and it lies inside a UNESCO biosphere reserve.

Explanation

How a radial pattern forms here

• Cause: a high centre
• The plateau stands higher than the land around it.

• The ground slopes down on every side.

• Process: water runs downhill in all directions

• Rain falling on the top drains off each slope.

• Each slope gives birth to its own stream.

• Result: rivers spread out like the spokes of a wheel

• This shape is called a radial drainage pattern (rivers flowing outward from one high centre).
• A drainage pattern is the shape that a river and its tributaries (smaller streams that join it) make on a map. Slope, rock structure and the history of the land decide this shape [2].

Rivers that leave the plateau

Direction	River	Where it goes
West	Narmada	Arabian Sea. It is the largest west-flowing river of Peninsular India [3]
North	Son	Joins the Ganga as a right-bank tributary
East and south	Mahanadi headwater streams, e.g. the Arpa	Mahanadi system, then the Bay of Bengal

• Narmada source: the Narmada rises in the Maikala range near Amarkantak, in Anupur district, Madhya Pradesh, at about 1,057 m [3].
• The Narmada's path:
• It flows west in a rift valley (a long, low trough formed where land sank between faults).

• The Vindhyas are to its north, the Maikala range to its east, the Satpuras to its south and the Arabian Sea to its west [3].

• Note on the Mahanadi: only some headwater streams of the Mahanadi system, such as the Arpa, start on Amarkantak's slopes. The main Mahanadi river rises elsewhere in Chhattisgarh.

The forest and biosphere link (NCERT Ch 5)

• The plateau lies in the Achanakmar–Amarkantak Biosphere Reserve [4].
• A biosphere reserve is a large protected area. Its core is kept untouched, and people live and work around it in ways that do not harm it.
• This reserve is part of UNESCO's Man and the Biosphere (MAB) network. It is one of the least disturbed and most ecologically varied landscapes in Chhattisgarh and Madhya Pradesh [4].
• Why the forest matters for rivers:
• Forest cover soaks up rain and releases it slowly.
• This keeps the headwater streams flowing after the rains are over.

Where it occurs

• Location: Maikal (Maikala) range, on the Madhya Pradesh–Chhattisgarh border. The Narmada source is in Anupur district, MP [3].
• Rivers fed: the Narmada (westward, into Madhya Pradesh and on to the Arabian Sea), the Son (northward, into the Ganga system) and Mahanadi-system streams like the Arpa (into Chhattisgarh, then the Bay of Bengal).
• Protected area: Achanakmar–Amarkantak Biosphere Reserve, across Chhattisgarh and Madhya Pradesh, listed in UNESCO's MAB network [4].
• World setting: radial drainage is typical of volcanic cones, as long as the cone has not been worn down too much [2]. Amarkantak is an Indian plateau example of the same pattern.

Don't confuse with

• Centripetal drainage: rivers flow inward into a low central lake or hollow, e.g. Loktak (Manipur) and Sambhar (Rajasthan). Amarkantak is the opposite: rivers flow outward from a high centre.
• Annular drainage: streams curve in rings around an eroded dome [2]. In radial drainage, as at Amarkantak, rivers run straight out from the centre.
• Dendritic drainage: a tree-like pattern with acute-angle joins on uniform rock, e.g. the northern plain rivers. It grows from many branches joining one trunk, not from rivers spreading out of one high point.
• Source of the Mahanadi: Amarkantak feeds Mahanadi headwater streams (e.g. the Arpa). It is not the source of the main Mahanadi river. Its classic river sources are the Narmada and the Son.

Prelims Hooks

• Amarkantak → Maikala range → Anupur district, MP → about 1,057 m → source of the Narmada [3].
• Radial pattern trio: Narmada flows west, Son flows north, Mahanadi headwaters (e.g. Arpa) flow east and south.
• The Narmada is the largest west-flowing river of Peninsular India [3]. It flows between the Vindhyas (north) and the Satpuras (south).
• The Son is a right-bank tributary of the Ganga that rises at Amarkantak.
• Amarkantak lies in the Achanakmar–Amarkantak Biosphere Reserve, part of UNESCO's MAB network [4].
• Trap: radial = Amarkantak (outward). Centripetal = Loktak, Sambhar (inward). Rectangular = Vindhyas, Chambal (faults and joints).

Mains Points

• A water tower for several states (GS-I and GS-III):
• One plateau feeds three river systems: the Narmada, the Son (Ganga basin) and the Mahanadi.
• Cutting forests or mining here would reduce river flows and add silt downstream in Madhya Pradesh, Chhattisgarh and beyond.

• Response: protect the catchment through the Achanakmar–Amarkantak Biosphere Reserve [4], and manage the river basins jointly across states.

• Drainage pattern shows the land's shape: the radial pattern shows that Amarkantak is a high centre that slopes down on all sides. The Narmada's westward path through a rift valley between the Vindhyas and the Satpuras [3] shows how rock structure guides rivers. Knowing this helps in planning dams, canals and river interlinking.

Related concepts

• Drainage pattern
• Dendritic drainage pattern
• Radial drainage pattern
• Trellis drainage pattern
• Centripetal drainage pattern

Read more

• Drainage patterns