Drainage System of India: Himalayan and Peninsular Rivers

Two drainage systems

Feature	Himalayan rivers	Peninsular rivers
Source	Glaciers + monsoon	Mainly monsoon rain
Flow	Perennial	Mostly seasonal
Valleys	Deep gorges (antecedent)	Broad, shallow, graded
Course	Meandering, shifting	Fixed, straight

Himalayan systems

• Indus: rises near Mansarovar (Tibet); tributaries Jhelum, Chenab, Ravi, Beas, Sutlej. Governed by the Indus Waters Treaty (1960).
• Ganga: Bhagirathi (from Gangotri glacier) meets Alaknanda at Devprayag. Tributaries: Yamuna, Ghaghara, Gandak, Kosi ("Sorrow of Bihar"), Son.
• Brahmaputra: called Tsangpo in Tibet, Dihang/Siang in Arunachal Pradesh, Jamuna in Bangladesh.

Peninsular systems

• East-flowing (form deltas, drain into the Bay of Bengal): Mahanadi, Godavari (largest peninsular river, "Dakshin Ganga"), Krishna, Kaveri.
• West-flowing (form estuaries, drain into the Arabian Sea): Narmada and Tapi, which flow through rift valleys.

Prelims pointers

1. The Western Ghats act as the main water divide of the peninsula.
2. Rivers crossing the Himalaya before it rose (Indus, Sutlej, Brahmaputra) are antecedent rivers.

Analogy

Himalayan rivers are like taps connected to a huge overhead tank (glaciers) plus rain; peninsular rivers are like buckets that fill only when it rains. That is why the Ganga keeps flowing in May while many peninsular rivers shrink to a trickle.