The Peninsular River System
The Peninsular river system is older than the Himalayan river system. It is evident from the broad, largely-graded shallow valleys, and the maturity of the rivers.
The Peninsular River System
The Western Ghats running close to the western coast is the main water divide between the major Peninsular rivers, discharging their waters in the Bay of Bengal and as small rivulets joining the Arabian Sea.
Most of the major Peninsular rivers except Narmada, Tapi, Sabarmati and Mahi flow towards the west. Mahanadi, Kaveri, Godavari, Krishna rivers have a fixed course and there is an absence of meanders, and the flow of water is non-perennial. And Narmada and Tapi flow through the rift valley.
Evolution of the Peninsular Drainage
Three major events in the geological history of India has lead to the present drainage pattern in Peninsular India
During the tertiary period, the western part of the peninsula cracked and submerged in the sea. This even lead to the creation of various rift and trough. Also, the initial symmetrical pattern of drainage on either side of Sahyadri-Aravali axis changed forever through this event.
The formation of Himalayas leads to the subsidence of the Northern flank of the peninsular block and the creation of rift valleys. These rift valleys are drained by the Narmada and Tapi rivers.
Slight tilting of the peninsular block from northwest to the south-eastern direction gave orientation to the entire drainage system towards the Bay of Bengal during the same period.
Peninsular India is sapped by following major river systems:
*These rivers are discussed in separate articles in this series.
- The Narmada River
- The Tapi River
- The Luni River
- The Sabarmati River
- The Mahi River
- The Ghagghar River
- The Godavari River
- The Mahanadi River
- The Pennar River
- The Krishna River
- The Kaveri River
- The Subarnarekha River
- The Vaigai River
Comparison between the Himalayan River System and the Peninsular River System:
- While the Himalayan rivers originate from the Himalayan mountains covered with glaciers, the Peninsular rivers originate from the Peninsular plateau and central highland.
- The Himalayan rivers are perennial in nature and receive water from the glaciers and rainfall. Whereas, the Peninsular rivers are seasonal in nature and are dependent on monsoon rainfall.
- The drainage pattern of the Himalayan rivers and the Peninsular rivers also differ. The Himalayan rivers are antecedent and consequent leading to dendritic drainage pattern in the plains. On the other hand, the Peninsular rivers are super-imposed and rejuvenated leading to trellis, radial and rectangular drainage pattern.
- The Himalayan rivers usually have a long course. They flow through the rugged mountains and experience headward erosion and river capturing. In the plains, the Himalayan rivers are characterised by meandering and shifting of course. Whereas, the Peninsular rivers have smaller and fixed course with well-adjusted valleys.
- The Himalayan rivers have very large basins as their catchment area, whereas, the Peninsular rivers have relatively smaller basins.
- The Himalayan river system is young and youthful, and the rivers are active and deepening in the valleys. The Peninsular river system, however, is older. The rivers are broad and have largely-graded shallow valleys having almost reached their base levels.