The Northern Plains

5 min

Relief belts, soil zones, and regional river divisions

Core Concept

The Northern Plains run south of the Himalayas through deposition by the Indus, Ganga, and Brahmaputra systems. From north to south, relief features divide into Bhabar, Terai, Bhangar, and Khadar. Khadar is fertile new alluvium replenished annually, while Bhangar consists of older alluvium with calcareous kankar deposits.

Why This Matters

Direct questions on Bhabar porosity and Terai swamps appear frequently in SSC CGL, CHSL, and State PCS.
Differences between older Bhangar and fertile Khadar soils are standard CAPF and CDS staples.
Punjab doabs and the Brahmaputra riverine plain are heavily tested across all competitive exams.

Memory Hooks

Sequence N to S: 'B-T-B-K' = Bhabar (Boulders) -> Terai (Tangled swamp) -> Bhangar (Basi/Old) -> Khadar (Kheti-friendly).
Khadar = 'Khaad' (rich in manure and new silt); Bhangar = 'Bhangar' (scrap/old junk with coarse kankar).
Punjab = 'Panj-Aab' (Land of 5 Rivers/Doabs); Majuli = Brahmaputra's giant riverine island.

Relief Belts Comparison

Belt	Location	Key Characteristic	Soil / Fertility
Bhabar	Shiwalik foothills	Streams disappear in pebbles	Unsuitable for crops
Terai	South of Bhabar	Streams re-emerge; marshy	Rich forest cleared for crops
Bhangar	Above floodplains	Terrace features with kankar	Old alluvium, moderate
Khadar	Active floodplains	Flooded almost every year	New alluvium, highly fertile

Zone Visuals

BHABAR

(Porous Pebble Belt)

Porous Pebble Belt

Mountain streams vanish beneath 8 to 10 km wide pebble beds.

TERAI

(Wet Marshy Zone)

Wet Marshy Zone

Re-emerged streams create a damp wildlife-rich marshland belt.

BHANGAR

(Elevated Terrace)

Elevated Terrace

Older alluvium lying above flood levels containing hard kankar.

KHADAR

(Low Floodplain)

Low Floodplain

Annually flooded lowland enriched with fine fertile river silt.

Exam Traps

Bhangar is younger alluvium than KhadarKhadar is younger alluvium than Bhangar

Khadar is renewed every year by flood deposits, whereas Bhangar represents older, elevated alluvium.

Rivers disappear underground in TeraiRivers disappear in Bhabar, emerge in Terai

Porosity of pebbles in Bhabar swallows the water; it re-emerges on the surface in Terai.

Kankar nodules are abundant in KhadarKankar nodules are found in Bhangar

Calcareous deposits called kankar are characteristic of older alluvium (Bhangar), not fine Khadar.

Exam Practice

Q1.In which physiographic zone of the Northern Plains do streams sink and disappear underground?

Q2.The older alluvium of the Northern Plains containing calcareous deposits is known as:

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