The Geological Overview of Bihar

Bihar lies in eastern India, between latitudes 24°20’10” N and 27°31’15″N and longitudes 83°19’50″E and 88°17’40″E. It is a landlocked state in the temperate zone’s subtropical section. Bihar is located between humid West Bengal in the east and sub-humid Uttar Pradesh in the west, giving it a transitional position in terms of climate, economy, and culture. It is bounded to the north by Nepal and to the south by Jharkhand. The river Ganges, which flows through the center from west to east, divides the Bihar plain into two unequal parts (North Bihar and South Bihar). Bihar’s terrain has an average elevation of 173 feet above sea level.

 Geology of Bihar

Bihar is located in the Indo-Gangetic plain, therefore naturally fertile soil is one of the state’s assets. Thus, the soil of the Indo-Gangetic plain is the foundation of agricultural and industrial development. The Indo-Gangetic plain in Bihar is composed of a thick alluvial layer of drift origin that overlies the Siwalik and older tertiary rocks for most of the geology of Bihar. The soil is primarily young loam that is renewed year after year by the regular deposition of silt, clay, and sand carried by streams, but primarily by floods in Bihar.

This soil is poor in phosphoric acid, nitrogen, and humus, while potash and lime are frequently abundant. The most prevalent soil in Bihar is Gangetic alluvium from the Indo-Gangetic plain region, Piedmont Swamp Soil from the northwestern part of West Champaran district, and Terai Soil from the eastern part of Bihar along the Nepal border. Bihar has a lot of clay soil, sand soil, and loamy soil. This is the geology of Bihar.

Physiographic Divisions of Bihar

Bihar has three parts based on physical and structural conditions or also known as the physiographic division of Bihar: the Southern Plateau Region, Bihar’s Gangetic Plain, and the Shivalik Region.

The Shivalik Range Region

It is the first part of the physiographic division of Bihar. The Shiwalik Ranges and its Terai Region may be located in the northwestern section of Bihar’s Western Champaran. It covers an area of 932 square kilometers. In Bihar, this region symbolizes the Tertiary Rock System. The Shivalik Hills are offshoots of the Himalayan chain, and this sub-Himalayan foothills region is located in northern Bihar. In the very north of West Champaran, there are several tiny hills such as the Someshwar hills and the Dun hills. The Terai region, which is swampy and poorly populated, sits south of it.

The Bihar Plain

The second part of the physiographic division of Bihar is Bihar’s Plain, located between the Southern Plateau and the Northern Mountains, and it is delimited by a 150m contour line in both the north and south. The Ganga is the most important river in Bihar, and it is joined by the rivers Ghagra, Gandak, Burhi Gandak, Bagmati, Kamla-Balan, Kosi, and Mahananda, which flow southward from the Himalayas in the northern section of the Gangetic Plain. The Ganges River divides the huge fertile Bihar Plain into two unequal parts: North Bihar and South Bihar.

Northern Bihar Plain

It is situated in East Champaran and West Champaran (upper elevation Terai areas), as well as the plains of Samastipur, Begusarai, Saharsa, and Katihar. The Saryu, Gandak, Burhi Gandak, Bagmati, Kamla-Balan, Kosi, and Mahanadi rivers, as well as their tributaries, drain the region.

Southern Bihar Plain

It is narrower than Bihar’s northern plain and triangular due to the presence of many hills in this region, including the hills of Gaya, Rajgir, Giriak, Bihar Sharif, and Sheikhpura, Jamalpur, and Kharagpur.

The Bihar Plateau(Rohtas Bihar Plateau)

The third part of the physiographic division of Bihar is the Bihar Plateau also Known as Rohtas Bihar Plateau. The Southern Plateau Region stretches from the Kaimur district in the west to the Banka district in the east. It is composed of hard rocks such as gneiss, schist, and granite. This region features various conical hills formed by batholim, such as Pretshil, Ramshila, and Jethian hills. It is referred to as the Rohtas Bihar Plateau or the Kaimur Plateau.

The Rohtas Bihar Plateau, also known as the Kaimur Plateau, is around 800 square miles in size (2,100 km2). It’s a sloping tableland. It reaches a height of 1,490 feet (450 meters) above sea level at Rohtasgarh. The Rohtas Bihar plateau is a famous geographical figure in Bihar.

Significant waterfalls along Rohtas Bihar Plateau are: Devdari Falls (58m) on the Karmanasa River, Telharkund Falls (80m) on the Suara West River, Suara Falls (120m) on the Suara East River, Durgawati Falls (80m) on the Durgavati River, Okharean Kund Falls (90m) on Gopath River, Dhuan Kund Falls (30m) (near Sasaram) on the Dhoba River, Kuaridah Falls (180m) on the Ausane River, a tributary of Son River, and Rakim Kund Falls (168m), on the Gayghat River, a tributary of Ausane River.

Conclusion

The Ganges River divides Bihar into two unequal parts known as North and South Bihar. The river Ganges is the largest in the state of Bihar. Bihar is the twelfth-largest state in terms of land area, with 94,163 km2 (36,357 sq mi). Bihar is bounded to the west by Uttar Pradesh, to the north by Nepal, to the east by the northern section of West Bengal, and to the south by Jharkhand.