Peninsular Drainage System

Evolution Of Peninsular Drainage

• Geologists believe that the Sahyadri-Aravali axis was the main water divide in the past.
• According to one hypothesis, the existing peninsula is the remaining half of a bigger landmass.
• The Western Ghats were located in the middle of this landmass.
• So one drainage was towards east flowing into Bay of Bengal and the other towards west draining into Arabian Sea.
• The western part of the Peninsula cracked and submerged in the Arabian Sea during the early Tertiary period (coinciding with the formation of Himalayas).
• During the collision of the Indian plate, the Peninsular block was subjected to subsidence in few regions creating a series of rifts (trough, faults).

The now west flowing rivers of the Peninsula, namely the Narmada and the Tapi flow through these rifts.

• Straight coastline, steep western slope of the Western Ghats, and the absence of delta formations on the western coast makes this theory a possibility.
• It is believed that the west flowing peninsular rivers do not flow in the valleys formed by the rivers themselves.
• Rather they have occupied two fault rifts in rocks running parallel to the Vindhyas.
• These faults are supposed to be caused by the bend of the northern part of the Peninsula at the time of upheaval of the Himalayas.
• The Peninsula block, south of the cracks, tilted slightly eastwards during the event thus giving the orientation to the entire drainage towards the Bay of Bengal.
• Peninsula rivers are much older than the Himalayan rivers {Discordant}.
• The peninsular drainage is mainly Concordant except for few rivers in the upper peninsular region.
• They are non-perennial rivers with a maximum discharge in the rainy season.
• The peninsular rivers have reached mature stage {Fluvial Landforms} and have almost reached their base level. [Vertical down cutting is negligible] which are characterized by broad and shallow valleys.
• The river banks have gentle slopes except for a limited tract where faulting forms steep sides.
• The main water divide in peninsular rivers is formed by the Western Ghats, which run from north to south close to the western coast.
• The velocity of water in the rivers and the load carrying capacity of the streams is low due to low gradient.
• Most of the major rivers of the peninsula such as the Mahanadi, the Godavari, the Krishna and the Cauvery flow eastwards and drain into the Bay of Bengal.
• These rivers make deltas at their mouths. But the west flowing rivers of Narmada and Tapi as well as those originating from the Western Ghats and falling in the Arabian Sea form estuaries in place of deltas.
• There are few places where rivers form superimposed and rejuvenated drainage which are represented by  Examples: The Jog on the Sharvati (289 m), Yenna of Mahabaleshwar (183 m), Sivasamundram on the Cauvery (101 m), Gokak on the Gokak (55 m), Kapildhara (23 m) and Dhuandar (15 m) on the Narmada are the major waterfalls in the Peninsular India.
• Rivers that drain into Bay of Bengal: The Mahanadi, the Godavari, the Krishna, the Cauvery and several smaller rivers drains south-east into the Bay of Bengal.
• Rivers that drain into Arabian Sea: The Narmada, the Tapi, the Mahi flowing west as well as several small streams originating from the Western Ghats flow westwards into the Arabian Sea.

The Narmada River System

• The Narmada is a river located in central India.
• It rises to the summit of the Amarkantak Hill in Madhya Pradesh state.
• It outlines the traditional frontier between North India and South India.
• It is one of the major rivers of peninsular India. Only the Narmada, the Tapti, and the Mahi rivers run from east to west.
• The river flows through the states of Madhya Pradesh, Gujarat, and Maharashtra.
• It drains into the Arabian Sea in the Bharuch district of Gujarat.

The Tapi River System

• It is a central Indian river. It is one of the most important rivers of peninsular India with the run from east to west.
• It originates in the Eastern Satpura Range of southern Madhya Pradesh state.
• It flows in a westward direction, draining some important historic places like Madhya Pradesh’s Nimar region, East Vidarbha region and Maharashtra’s Khandesh in the northwest corner of the Deccan Plateau and South Gujarat before draining into the Gulf of Cambay of the Arabian Sea.
• The River Basin of Tapi River lies mostly in eastern and northern districts of Maharashtra state.
• The river also covers some districts of Madhya Pradesh and Gujarat as well.
• The principal tributaries of Tapi River are Waghur River, Aner River, Girna River, Purna River, Panzara River and Bori River.

The Godavari River System

• The Godavari River is the second-longest course in India with brownish water.
• The river is often referred to as the Dakshin (South) Ganga or Vriddhi (Old) Ganga.
• It is a seasonal river, dried during the summers, and widens during the monsoons.
• This river originates from Trimbakeshwar, near Nasik in Maharashtra.
• It flows southeast across south-central India through the states of Madhya Pradesh, Telangana, Andhra Pradesh, and Orissa, and drains into the Bay of Bengal.
• The river forms a fertile delta at Rajahmundry.
• The banks of this river have many pilgrimage sites, Nasik(MH), Bhadrachalam(TS), and Trimbak. Some of its tributaries include Pranahita (Combination of Penuganga and Warda), Indravati River, Bindusara, Sabari, and Manjira.
• Asia’s largest rail-cum-road bridge which links Kovvur and Rajahmundry is located on the river Godavari.

The Krishna River System

• Krishna is one of the longest rivers of India, which originates from Mahabaleshwar in Maharashtra.
• It flows through Sangli and drains the sea in the Bay of Bengal.
• The river flows through the states of Maharashtra, Karnataka, Telangana and Andhra Pradesh.
• Tungabhadra River is the main tributary which itself is formed by the Tunga and Bhadra rivers that originate in the Western Ghats.
• Dudhganga Rivers, Koyna, Bhima, Mallaprabha, Dindi, Ghataprabha, Warna, Yerla, and Music are some of the other tributaries.

The Cauvery River System

• The Cauvery is also known as Ganga of South India “Dakshin Bharat ki Ganga”.
• It originates from Talakaveri located in the Western Ghats.
• It is a famous pilgrimage and tourist place in the Kodagu district of Karnataka.
• The headwaters of the river are in the Western Ghats range of Karnataka state, and from Karnataka through Tamil Nadu.
• The river drains into the Bay of Bengal. The river supports irrigation for agriculture and is considered as a means of support of the ancient kingdoms and modern cities of South India.
• The river has many tributaries called Arkavathy, Shimsha, Hemavati, Kapila, Shimsha, Honnuhole, Amaravati, Lakshmana Kabini, Lokapavani, Bhavani, Noyyal, and Tirtha.

The Mahanadi River System

• The Mahanadi originates from the Satpura Range of central India and it is a river in eastern India.
• It flows east to the Bay of Bengal. The river drains the state of Maharashtra, Chhattisgarh, Jharkhand, and Orissa.
• The largest dam, the Hirakud Dam, is built on the river.

The following table illustrates the major differences between Himalayan and the Peninsular River system