Bihar Geography

Physical Divisions of Bihar

• The Central Gangetic Plain covers a major part of Bihar's area, with an average elevation of below 50 m.
• The Shiwalik foothills in the north have an elevation ranging from 200 m in the west to 100 m in the east.
• The hilly extensions of the Hazaribagh and Chota Nagpur Plateau in the south have an elevation between 200 m and 350 m.

Soil Types

• Alluvial soil deposited by rivers: khadar (fertile new alluvium) and bhangar (older alluvium).
• Khadar is deposited in the lower areas, whereas bhangar is found in the higher valleys and is coarse with calacareous/lime nodules called 'kankar'.
• Loose, coarse, gravelly bhabar soil is found along the foothills of the Shiwaliks.
• Red and yellow soils are found along the hilly southern borders.

Climate

• Bihar has a subtropical to warm temperate climate, with hot summers and mild winters.
• Summer temperatures in the southern region can rise from 35°C to 43°C.
• The lowest temperatures in the extreme north in the Shiwalik foothills are around 27°C.
• Winters are mild to cold, with temperatures ranging from around 15°C in the higher regions to an average of 17°C to 20°C over the rest of the state.

Rainfall

• Rainfall in Bihar is brought by the Southwest Monsoon winds during late June-July.
• Pre-monsoon showers associated with hot, dry, and dusty winds may bring a little rainfall from April to May.
• Rainfall decreases from about 200cm in the east to 100cm in the west.