Describe in short the formation of northern plains.

The formation of northern plains:

(i)The northern plain has been formed by the interplay of the three major river systems, namely– the Indus, the Ganga and the Brahmaputra along with their tributaries.

(ii)This plain is formed of alluvial soil.

(iii)The deposition of alluvium in a vast basin lying at the foothills of the Himalaya over millions of years, formed this fertile plain.