Bhabar

Topic: Structure and Physiography of India: Himalayas, Plains, Peninsula, Coasts and Islands · NCERT: Class 11, Ch 2 "Structure and Physiography"

Meaning

Bhabar is a narrow belt of coarse, porous rock waste, about 8-10 km wide, that runs along the foot of the Shiwalik hills. Here, rivers coming down from the mountains drop boulders, pebbles and gravel, and small streams sink into the ground and vanish.

It is the first and northernmost zone of the Northern Plain. Its porous ground feeds the water that comes back up further south in the tarai. This makes it a key link in exam questions on the order and features of the plain's zones.

Explanation

How it forms (cause → process → result)

• Cause: the break of slope
• A break of slope is the line where steep hills suddenly meet flat ground.

• Rivers leaving the Shiwalik hills reach this line and slow down quickly.

• Process: heaviest load is dropped first

• A slower river has less energy and cannot carry its load.
• It drops the heaviest material first: boulders, pebbles and gravel.

• Finer sand, silt and clay are carried further south.

• Result: a porous belt where streams disappear

• Big stones leave large gaps between them, so the ground is very porous (water passes through it easily).
• Small streams sink into this material and vanish from the surface.
• The water keeps flowing underground towards the south.

Main features

• Width: about 8-10 km. It runs parallel to the Shiwalik hills.
• Material: coarse, unsorted deposits (boulders, pebbles, gravel), not fine alluvium.
• Surface: dry, because water drains down quickly.
• Farming: poor. The soil is stony and cannot hold water.
• Vegetation: good for forest more than for crops. Corbett Tiger Reserve (Uttarakhand) lies in the bhabar tract and is the most intact habitat unit in the region [2].

Its place in the Northern Plain

• The bhabar is a piedmont alluvial plain. Piedmont means "at the foot of the mountain". It is land built by rivers dropping coarse sediment where they leave the hills.
• Order from north to south: Shiwalik foothills → Bhabar → Tarai → Bhangar/Khadar → delta.
• Link with the tarai:
• Water that sinks into the bhabar flows underground.
• Further south, the sediment becomes finer and less porous.

• There the water comes back up to the surface and forms the marshy tarai belt (10-20 km wide).

• The particle size gets smaller from north to south: boulders in the bhabar, then finer silt and clay in the bhangar and khadar.

Where it occurs

• India:
• Along the foot of the Shiwalik hills, at the northern edge of the Indo-Ganga-Brahmaputra plain.
• Uttarakhand: the bhabar tract holds Corbett Tiger Reserve [2].
• It lies just north of the tarai of Uttarakhand (e.g. Udham Singh Nagar) and Uttar Pradesh.

• It is part of the bhabar-tarai belt, which falls in the Terai Arc Landscape. This forest and grassland belt crosses the India-Nepal border [2].

• Related piedmont zones in India:

• Duars: the foothills of north Bengal and Assam, known for tea gardens.

• Chos: seasonal torrents in the Punjab Shiwaliks (Hoshiarpur area) that cut deep gullies.

• World: similar coarse belts form at the foot of mountain ranges wherever fast rivers come out onto a plain and drop their load at a break of slope. These are piedmont deposits and alluvial fans (fan-shaped heaps of sediment at a mountain foot).

Don't confuse with

• Tarai: the bhabar is the dry zone where streams disappear. The tarai (10-20 km wide, south of the bhabar) is the wet, marshy zone where they re-emerge.
• Bhangar: also lies above flood level, but it is made of older fine alluvium on terraces with kankar (lime nodules). The bhabar is made of boulders and gravel at the hill foot.
• Khadar: newer, fine, very fertile alluvium on floodplains, renewed by floods almost every year. The bhabar is coarse, stony and poor for farming.
• Duars / Chos: these are also piedmont features. Duars are the foothills of north Bengal and Assam (tea gardens). Chos are erosive seasonal torrents in the Punjab Shiwaliks. Neither is the 8-10 km belt where streams vanish.

Prelims Hooks

• North-to-south order: Shiwalik → Bhabar → Tarai → Bhangar → Khadar.
• Width: bhabar 8-10 km, tarai 10-20 km. Don't swap them.
• Process–zone pair: streams sink and disappear → bhabar. Streams re-emerge and form marshes → tarai.
• Material: bhabar = boulders, pebbles, gravel (coarse, porous). Kankar belongs to bhangar, not bhabar.
• Tiger reserve match: Corbett → bhabar (Uttarakhand). Dudhwa → tarai (UP). Valmiki → Bihar's only tiger reserve [2][3][4].
• Trap: the bhabar is a piedmont deposit formed at a break of slope. It is not a floodplain and not the most fertile part of the plain.

Mains Points

• Groundwater link (GS-I):
• The porous bhabar soaks up stream water from the Shiwaliks.
• This water flows underground and comes back up in the tarai, which creates its marshes, forests and grasslands.

• Disturbing the bhabar (for example, mining boulders or clearing forest) can change water flow in the whole foothill belt.

• Land use and conservation (GS-III, environment):

• The bhabar is dry and stony, so it stayed under forest more than the fertile plains did.
• Corbett Tiger Reserve in the bhabar tract is the most intact habitat unit in the region [2].

• After 1950, the neighbouring tarai was cleared for farms and resettlement, so habitat broke into pieces. The Terai Arc Landscape now links Corbett, Dudhwa and Valmiki with Nepal's parks as a cross-border wildlife corridor [2][4].

• Regional development (GS-I): the bhabar's poor soil and dry surface explain why the densest farming and settlement are found further south on the bhangar and khadar. This is one reason the plain's population and farming are spread so unevenly from north to south.

Related concepts

• Indo-Ganga-Brahmaputra plain
• Tarai
• Bhangar
• Khadar
• Piedmont alluvial plains
• Riverine island
• Majuli
• Ganga-Brahmaputra delta

Read more

• The Northern Plain: bhabar, tarai, bhangar, khadar and the deltas