Peninsular Drainage System of India

The Peninsular Drainage System is an extensive network of rivers that flow across the Indian Peninsula, originating from the central highlands and flowing towards the surrounding seas – the Bay of Bengal to the east and the Arabian Sea to the west. The evolution of this drainage system has been influenced by geological processes and the shifting landscape over millions of years. Here is a breakdown of the key points in the evolution of the Peninsular Drainage System:

1. Landmass Formation and Division: Geologists propose that the Sahyadri-Aravali axis acted as a primary water divide in the past. The current Indian Peninsula might have been a larger landmass, with the Western Ghats situated centrally. This division resulted in rivers flowing eastward into the Bay of Bengal and westward into the Arabian Sea.

2. Submergence and Faulting: During the early Tertiary period, a portion of the western part of the peninsula submerged into the Arabian Sea, coinciding with the formation of the Himalayas due to the collision of tectonic plates. This event led to the creation of rifts and faults in the peninsular region.

3. Rift Formation: The collision of the Indian plate led to subsidence in certain areas of the Peninsular block, giving rise to rifts and troughs. Rivers like the Narmada and the Tapi now flow through these rifts, creating their courses.

4. Orientation Shift: The southern part of the peninsula tilted slightly eastwards during the Himalayan uplift, causing the overall drainage orientation to shift towards the Bay of Bengal.

5. Drainage Patterns: The Peninsular Drainage System exhibits different drainage patterns, including concordant patterns that follow the slope of the land, as well as few discordant patterns in the upper regions. The rivers have matured over time and have almost reached their base levels.

6. Major Rivers and Basins: The main water divide in the peninsular rivers is formed by the Western Ghats, which run parallel to the western coast. The Mahanadi, Godavari, Krishna, and Cauvery are some of the major rivers flowing eastward into the Bay of Bengal, forming deltas at their mouths. The Narmada and Tapi, along with other westward-flowing rivers originating from the Western Ghats, form estuaries on the Arabian Sea coast.

7. Waterfalls and Landforms: The Peninsular Drainage System features some impressive waterfalls, such as Jog Falls, Yenna Falls, Sivasamundram Falls, Gokak Falls, Kapildhara, and Dhuandar. These waterfalls are often associated with superimposed and rejuvenated drainage patterns.

In summary, the evolution of the Peninsular Drainage System is shaped by geological processes, rift formation, tectonic events, and shifts in landmass configuration. The rivers that emerged have established their courses, exhibiting various drainage patterns, and supporting diverse landscapes and ecosystems across the Indian Peninsula.

The formation and evolution of the Peninsular Drainage System have been influenced by various geological processes over millions of years. Here's a concise recap of the key points:

Formation of Water Divide:

• In the past, the Sahyadri-Aravali axis acted as the primary water divide in the region.

• One theory suggests that the current Indian Peninsula represents the remaining half of a larger continent, with the Western Ghats situated in its center. This configuration led to the division of drainage into the Bay of Bengal to the east and the Arabian Sea to the west.

Tertiary Era Events:

• During the early Tertiary period, a significant portion of the western peninsula fractured and submerged under the Arabian Sea. This coincided with the formation of the Himalayas due to tectonic activity.

• The collision of the Indian plate with the Peninsular block caused subsidence in certain areas, leading to the creation of rifts and faults.

Rift Formation and Rivers:

• These rifts formed pathways for west-flowing rivers like the Narmada and the Tapi, which now follow these geological features.

• This theory gains support from the straight coastline, steep western slope of the Western Ghats, and the absence of delta formations on the western coast.

Major Rivers and Basins:

• Prominent east-flowing rivers into the Bay of Bengal include the Mahanadi, Godavari, Krishna, and Cauvery.

• West-flowing rivers into the Arabian Sea comprise the Narmada, Tapi, and other smaller streams originating from the Western Ghats.

Specific River Systems:

• Mahanadi: Originates from Chhattisgarh's Raipur District and flows through Odisha. Major tributaries include the Seonath, Hasdeo, Mand, Ib, Ong, Tel, and Jonk.

• Godavari: Emerges from Trimbakeshwar in Maharashtra, flowing through Andhra Pradesh, Chhattisgarh, and Odisha. It features tributaries like Pranahita, Indravati, and Bindusara.

• Krishna: Originates from Maharashtra's Satara district and flows through Andhra Pradesh and Karnataka. It has tributaries like Tungabhadra, Bhima, and Musi.

• Cauvery: Originates in Karnataka's Kodagu district, flowing through Tamil Nadu and Kerala. Tributaries include Arkavathy, Shimsha, Hemavati, and Bhavani.

West-flowing Rivers:

• Narmada: Emerges from Madhya Pradesh's Amarkantak Hill and flows through Gujarat and Maharashtra. Its tributaries are numerous, including Barna, Hiran, Tendoni, Choral, Kolar, Man, Uri, Hatni, and others.

• Tapi: Originates in Madhya Pradesh and flows through Maharashtra and Gujarat. Tributaries include Suki, Gomai, Arunavati, Aner, Vaghur, Amravati, and more.

• Mahi: Flows through Madhya Pradesh, Rajasthan, and Gujarat. Tributaries like Som, Anas, Panam, and Anas contribute to its flow.

Importance and Characteristics:

• Peninsular rivers are rain-fed and generally flow only during the rainy season.

• Rivers have relatively shallow valleys, with minimal erosional activity.

• Estuaries are formed by west-flowing rivers, while deltas are formed by east-flowing rivers.

• Due to the plateau's non-alluvial composition, meanders are limited, resulting in straight river courses.

Conclusion: The Peninsular Drainage System's formation is a result of geological processes like rift formation, subsidence, and tectonic activity. The various rivers that have evolved in this region contribute significantly to the landscape, economy, and ecosystems of the Indian Peninsula.

 

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