The correct option is 2 and 3 only
Explanation
The Northern Plains of India are formed by the interplay of the three major river systems-the Indus, the Ganga, and the Brahmaputra-along with their tributaries. These plains are depositional landforms characterized by vast alluvial deposits and specific relief features based on the variation in relief.
Statement 1 is Incorrect:
The classification of the Northern Plains based on relief features distinguishes between Bhangar and Khadar.
- Bhangar is the largest part of the Northern Plain and is composed of old alluvial soil. It lies above the flood plains of the rivers and presents a terrace-like feature. It often contains calcareous deposits known as 'Kankar'.
- Khadar consists of new alluvial deposits found in the floodplains. These deposits are renewed almost every year and are thus very fertile, making them ideal for intensive agriculture.
Statement 2 is Correct:
The rivers flowing through the Northern Plains are generally in the mature stage of their course. Consequently, the plains exhibit characteristic features of mature fluvial erosional and depositional landforms, such as sandbars, meanders, oxbow lakes, and braided channels. The gentle slope of the plains reduces the velocity of the river water, promoting deposition.
Statement 3 is Correct:
The Brahmaputra plains are specifically known for the presence of riverine islands and sand bars. This is due to the river's significant depositional activity and its tendency to form braided channels. Majuli, located in the Brahmaputra River, is the largest inhabited riverine island in the world.
Key Takeaway:
Bhangar refers to old, less fertile alluvium located on higher terraces, while Khadar refers to new, highly fertile alluvium found in floodplains. The Northern Plains are dominated by depositional landforms typical of a river's mature stage.