Coastal plains of India: An Amazing Geologic Feature!

Coastal plains in India

Coastal plains of India are the waved platforms and the raised beaches above the water mark. These are mainly the emerged floors from the seas that are adjacent to the land. The Peninsular India plateau is bordered by the narrow Coastal Plains. Following the surfacing of these lowlands, the sea level fluctuations have brought some important changes in the surface features of the sea shores. The Deccan plateau in India is also surrounded by the coastal plains in the west and the east.

The Coastal plains that surround the Palghat town in the southern region of Kerala are comparatively broad.  In some places the width of the plains get extended to about 96km. The off-shore bars are enclosed with lagoons running parallel to the coastal plains in the south of Kerala. Also referred as Kayals, the lagoons receive water from numerous rivers, to which these are linked through narrow openings. The coastal zone located in the western part alongside the Arabian Sea is known in the south of Goa, as Malabar, while in the north of Goa, it is called Konkan.

Further, there are numerous estuaries in the Indian Coastal Plains. Among these, the major ones are Narmada River and Tapi River in the state of Gujarat. The plain is also blessed with natural harbors such as Marmagao and Mumbai. In the south, the coastal plains get combined with the salt water lakes also known as lagoons. Spits and sand bars can be found at their mouths. The coast is popular for the serene backwaters. The coastal plains alongside the Bay of Bengal are very extensive and also differ from the plains in the western strip. Fast flowing, small rivers cut part the rocky coastal strip.

That what separates the coastal plains in India from the interior is a large land of mass characterized by unique features. Though having limited vegetation, yet the coastal plains in India significantly contributes to the geography of the country. Coastal plains of India: An Amazing Geologic Feature can be found both on the eastern as well the western coasts of the country. Hence the Coastal Plains in India can be divided into 2 basic types, namely, the Eastern Coastal Plains and the Western Coastal Plains.

The Eastern Coastal Plains

Nestled within the Bay of Bengal and the Eastern Ghats, is the eastern coastal plains, a wide stretch of land having a width of about 120km. The plains extend from the state of Tamil Nadu in the southern part to the state of West Bengal in the northern region of India. There are several rivers that drain the eastern coastal plains of India. There are few river deltas as well that occupy these valleys.

These plains experience a temperature of over 30 degrees Celsius, characterized by high humidity level. Abundant rainfall is received by this region that amounts in between 1000mm to 3000mm annually. The plains are subject to southwest as well as northeast monsoon rains.

The peninsulas of Kutch and Kathiawar, the Rann of Kutch, and the Gujarat Plain serve as the important physiographic regions. Lying north of the Kutch is presently a huge desolate plain that got formed by the deposition of silt. Kutch that lies on the southern side of the Rann of Kutch was previously an island. Now it happens to be a sandy terrain alongside the coastal plains. On the south of the Kutch is Kathiawar. It is a hilly, rolling plain having an elevation of 200m. Huge amount of sediments are deposited by the Narmada River, Tapti River, Sabarmati River and Mahi River into the Gulf of Cambay. This has resulted in the coming up of a fertile land in the north of Daman. This plain extending towards north up to the Aravalli Mountain Ranges is known as the Gujarat Plain.

The eastern coastal plains are characterized by numerous rivers, large deltas, fertile and irrigated lands, lagoons, spits and off-shore bars. At places the plains are bordered with dunes. Mangrove forests also grow in this region. Following shallowness of the sea in the Eastern Coastal lowlands, there is no deep natural harbor in the region except Marmagao (Goa) and Mumbai. Locally the eastern coastal plain is known as the Northern Circars in the region between Krishna and Mahanadi rivers whereas in regions between the Kaveri and the Krishna River, it is known as Carnatic.

In the state of Tamil Nadu, the eastern coastal plain is much wider, stretching to about 100 to 120km of width. The three main divisions into which the eastern coastal plains can be divided are the Andhra Plains, Utkal Plains and Tamil Nadu Plains.

Utkal Plains: This is the coastal stretch of the state of Orissa and consists of the Mahanadi delta. The famous feature of the region is the Chilka Lake lying on the south of the Mahanadi Delta.

Tamil Nadu Plains: The plains extend from the Pulicat Lake to Kanyakumari. The prominent feature of the region is the Kaveri delta, the fertile soil and irrigational facilities of which makes it a granary in South India.

Andhra Plains: The plains extend from the Utkal Plains on the North to Pulicat Lake in the south. The delta formation by the River Kaveri and River Godavari happens to be the important feature of the region.

The expansive area of the eastern coastal plains that is the three broad divisions, mentioned above can be further divided into 6 regions:

  1. Mahanadi Delta in Orissa
  2. Southern Andhra Pradesh Plain
  3. Krishna Godavari deltas
  4. Kanyakumari Coast
  5. Coromandel or Madras Coast in Tamil Nadu
  6. Sandy Coastal regions

Western Coastal Plains

In contrast to the eastern coastal plains, the western coastal plain of India is situated on a thin strip of land. The plains are nestled with the Arabian Sea and the Western Ghats. Having a length of about 1,400 kilometer and a breadth of 10-80 kilometer, the western coastal plans cover an area of about 64,284 square kilometer. Extending from the state of Gujarat, in the northern side to the south in the state of Kerala, the western coastal plains are characterized by many rivers and backwaters and rivers that drain into this area. The rivers that flow through this region, results in the formation of many estuaries in the western coastal plains. The storm activity experienced by these plains is less in comparison to the eastern coastal plains. Most of the storm activity that takes place in the western coastal plains is in March. When compared with the eastern coastal plains, the western coastal plains are small and can be divided into 3 parts, namely

  1. Konkan region that is the northern part of the coast
  2. Kanara region, which forms a separate transitional zone in between the Malabar coast
  3. Malabar Coast that is the southern part of the coast

The western coastal plains also consist of the states of Karnataka, Maharashtra and Goa. On the northern of the coast, there happens to be 2 gulfs namely the gulf of Khambat and the gulf of Kachch.