Complete Geography Notes on General Geography of Bihar and its major River system for BPSC and Other Competitive Exams in 2025

Complete Geography Notes on General Geography of Bihar and its major River system for BPSC and Other Competitive Exams in 2025

Geography-1

Here’s a detailed breakdown of the “General Geography and Geographical Division of Bihar and its Major River Systems” as per the BPSC Prelims Syllabus. The focus is on covering relevant topics concisely and comprehensively for Prelims preparation and will assist in Mains as well.

Introduction-Geography of Bihar

Bihar is situated in the eastern region of India. It shares its borders with Nepal to the north, Uttar Pradesh to the west, Jharkhand to the south, and West Bengal to the east.

The newly formed Bhojpur district includes three subdivisions—Ara Sadar, Jagdishpur, and Piro—comprising 14 development blocks and covering an area of 2,37,526 hectares. As per the 2011 report, the total population stands at 10,409,952.

The stretch of land between the Ganga River to the north and the Eastern Railway’s main line to the south is highly fertile. This area receives annual deposits of silt from the Ganga and is considered one of Bihar’s prime wheat-producing regions.

BPSC Prelims Syllabus Topic: General Geography of Bihar

I. Geographical Location and Extent of Bihar

• Location: Eastern India, between 24°20’10” N to 27°31’15” N latitudes and 83°19’50” E to 88°17’40” E longitudes.
• Bounded by:
  • North – Nepal (international border)
  • South – Jharkhand
  • East – West Bengal
  • West – Uttar Pradesh
• Area: 94,163 sq. km (approx. 2.86% of India’s total area)
• Position in India: 12th largest state by area, 3rd by population

II. Geographical Divisions of Bihar

Bihar is divided into three main physical/geographical regions:

1. The Northern Plains (North Bihar Plain)

• Area north of the Ganga river
• Formed by alluvium brought by Himalayan rivers
• Fertile soil, flood-prone (especially Koshi, Gandak, and Bagmati)
• Major districts: West Champaran, Sitamarhi, Darbhanga, Saharsa, etc.

2. The South Bihar Plain

• Lies south of the Ganga
• More stable terrain, with old alluvium
• Fertile but with patches of less productive laterite soils
• Districts: Patna, Gaya, Nalanda, Nawada, etc.

3. The Chotanagpur Plateau Fringe (Southern Hills)

• Extension of Chotanagpur Plateau from Jharkhand
• Hard rock terrain, poor soil fertility, forested
• Hills: Rajgir hills, Kaimur hills
• Districts: Rohtas, Aurangabad, Gaya (parts)

III. Major River Systems of Bihar

Bihar is a riverine state, dominated by the Ganga and its tributaries.

A. The Ganga River

• Lifeline of Bihar, flows west to east
• Enters from Chausa (Buxar) and exits near Manihari (Katihar)
• Divides the state into North and South Bihar
• Facilitates irrigation, agriculture, and transportation

B. Major Northern Tributaries (from the Himalayas):

1. Gandak (Narayani) – Origin: Nepal; joins Ganga near Hajipur
2. Burhi Gandak – Origin: Chautarwa Chaur (West Champaran)
3. Bagmati – Highly flood-prone; joins Kosi near Khagaria
4. Kamla-Balan – Tributary of Bagmati
5. Koshi – “Sorrow of Bihar”; joins Ganga near Kursela (Katihar)
6. Mahananda – Originates in Darjeeling; enters Bihar in Kishanganj

C. Southern Tributaries (from Chotanagpur Plateau):

1. Sone – Major tributary from Jharkhand; joins Ganga at Maner
2. Punpun – Origin: Jharkhand; flood-prone
3. Phalgu (Falgu) – Originates near Gaya; formed by Lilajan and Mohana
4. Karmanasha – Boundary river between Bihar and UP

IV. Important Lakes and Wetlands

• Kanwar Lake (Begusarai) – Largest freshwater oxbow lake in Asia
• Baraila Lake (Vaishali)
• Nagi and Nakti Dam (Jamui) – Bird sanctuary

V. Flood and Water Resource Issues

• North Bihar faces annual flooding due to Himalayan rivers
• South Bihar has drought-like conditions in some districts
• Major irrigation schemes: Gandak project, Koshi project, Sone command area

VI. Natural Resources

• Soils: Alluvial (north), Laterite and Red (south), Sandy (Kosi basin)
• Forest: Only 7.75% forest cover; mainly in southwest districts
• Minerals: Limestone (Rohtas), Mica (Gaya), Sand and stone chips

Summary: BPSC Prelims Geography of Bihar