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Western and Eastern Coastal Plains of India

Coastal Plains in India: India has a total of 7517 kilometres of coastline, of which 6100 km are on the peninsula between the peninsular plateau and the sea.

Western and Eastern Coastal Plains of India

Coastal Plains in India: India has a total of 7517 kilometres of coastline, of which 6100 km are on the peninsula between the peninsular plateau and the sea. India's peninsular plateau is bordered by slender coastal plains that vary in breadth from north to south. 

These can be broadly split into two categories based on their geographic location and current geomorphological processes:

• The western coastal plains
• The eastern coastal plains.

How were coastal plains formed?

India was a component of the Gondwanaland supercontinent. One hundred forty million years ago, it was there. The supercontinent separated, leaving the tectonic landmass of India all by itself. It travelled toward the Eurasian plate for millions of years before joining it.

India's regular and predominantly straight coastline results from Gondwanaland's disintegration during the Cretaceous epoch. The coastal plains of India were also created as a result, in addition to the southern coastline.

Western Coastal Plains: 

Extent: Between the Arabian Sea and the Western Ghats, a narrow band of coastal plains called the Western Coastal Plains is 50 km wide. These plains stretch from the coast of Gujarat in the north to the coast of Kerala in the south.

Physiography and other characteristics:

• India's west coast is both emerging and submerging. Faulting has caused the northern portion of the coast to be submerged, and the Kerala coast in the south is an example of an emerging shore.
• The western coastal plains are relatively small in the centre and gradually gain wider as they move north and south. Except for the coastal areas of Kachchh and Kathiawar, these are smaller than their eastern counterparts.
•  The South-West Monsoon winds have impacted the coast for six months since it is straight. So the coastal plains in the west are wetter than those in the east.
• The western coast's greater indentation than the eastern coast provides the natural prerequisites for developing ports and harbours. Important natural ports on the west coast include Kandla, Mazagaon, JLN port Navha Sheva, Marmagao, Mangalore, Cochin, etc.
• Coves (a very small bay), creeks (a short, sheltered waterway such as an inlet in a shoreline or channel in a marsh), and a few estuaries scattered over the western coastal plains. The two largest estuaries are those of the Narmada and the Tapi.
• No delta is formed by the rivers that pass across this coastal plain. Numerous little rivers flow down from the Western Ghats, creating a series of waterfalls.
• The Kayals - The "Kayals" are a distinctive feature of the Malabar coast (backwaters). The shallow lagoons or inlets of the sea that make up these backwaters run parallel to the coastline. These are important tourist destinations and are used for inland navigation and fishing. The Vembanad lake is the biggest of these lagoons. Kochi is located near the sea's entrance.

Subdivisions:

The western coastal plains may be divided into the following sub-sections

Kutch and Kathiawar region: Although Kathiawar is built of Deccan Lava and there are Tertiary Rocks in the Kutch area, Kutch and Kathiawar are still recognized as vital parts of the Western Coastal Plains since they have been levelled down.An island with seas and lagoons surrounding it was the Kutch Peninsula. Later, material from the Indus River, which once flowed through this region, was imported to fill these seas and lagoons. The recent drought has left the area with an arid and semi-arid terrain. The Great Rann is a salt-drenched plain to the north of Kutch. The Little Rann, its southern extension, is located on the seashore and southeast of Kachchh. South of the Kachchh is where you will find the Kathiawar Peninsula. Small streams emanate from a highland in the Mandav Hills' centre in all directions 

Gujarat Plain: East of Kachchh and Kathiawar is the Gujarat Plain, which slopes toward the west and southwest. The Narmada, Tapi, Mahi, and Sabarmati rivers formed the plain, which comprises the southern region of Gujarat and the Gulf of Khambhat's coastal regions. Although the eastern portion of this plain is suitable for farming, most of it is covered in wind-blown loess towards the ocean (heaps of sand). 

Konkan Plain: From Daman to Goa, the Konkan Plain is located south of the Gujarat plain (50 to 80 km wide). The Arabian Sea contains islands, cliffs, shoals, and other marine erosion-related phenomena. Around Mumbai, a significant embayment called Thane Creek forms a bay and serves as a great natural harbour.

Karnataka Coastal Plain: From Goa to Mangalore, it is a narrow plain with an average width of 30 to 50 kilometres. The Western Ghats' streams sometimes descend along precipitous hillsides to create waterfalls. When the Sharavati flows down such a steep slope, it creates the 271 m-tall Gersoppa (Jog) Falls, a spectacular waterfall.

Kerala Plain: Between Mangalore and Kanyakumari is the Kerala Plain, sometimes referred to as the Malabar Plain. Compared to the plain of Karnataka, this is much wider. The plain is low-lying. A key feature of the Kerala coast is the presence of lakes, lagoons, backwaters, spits, etc.

Eastern Coastal Plains:

Extent: These vast plains, which stretch between the Bay of Bengal and the Eastern Ghats, are wider on average than the West Coastal Plains at 120 km. These plains stretch from the Subarnarekha river to Kanyakumari along the West Bengal-Odisha border. The rivers Mahanadi, Godavari, Krishna, and Cauvery, which make up some of the greatest deltas, fill the littoral zone with alluvial material, forming a significant portion of the plains.

Physiography and other features:

• The ground is lifted, or the sea level is lowered to create the coastline of emergence. The emergence characteristics include bars, spits, lagoons, salt marshes, beaches, sea cliffs, and arches. The Tamil Nadu coast on India's east coast, in particular, is a coast of emergence.

• Dunes are constantly moving over the broader, drier eastern coastal plains.

• Here, where rivers pour into the Bay of Bengal from the east, are well-developed deltas. These include the Krishna, Kaveri, Godavari, and Mahanadi deltas.

• It has fewer ports and harbours due to its emergent character. Since the continental shelf reaches 500 km into the ocean, building effective ports and harbours is challenging.

• A significant landmark on the eastern coast is Chilika Lake. It is India's largest saltwater lake.

• This plain is referred to as the Northern Circars and the Carnatic, between the Mahanadi and Krishna rivers and between the Krishna and Kaveri rivers.

Subdivisions: Northern Circar and Coromandel Coast (or Payan Ghat) can be divided into two parts. 

Utkal Plain: The coastal regions of Odisha make up the Utkal Plain.

Part of it is the Mahanadi delta. The Chilka Lake is the most notable physiographic feature of this plain. The largest lake in the nation, its area ranges from 780 square kilometres in the winter to 1,144 square kilometres during the monsoon season.

Low hills dot the lowlands to the south of Chilka Lake.

Andhra Plain: It stretches up to Pulicat Lake and is located south of the Utkal Plain. This lake has been blocked by Sriharikota Island, a long dune (ISRO launch facility). The plain's most notable characteristic is the delta created by the Godavari and Krishna rivers. Together, the two deltas have fused to form a single physiographic unit. In recent years, the united delta has moved closer to the sea by around 35 kilometres. This is evident from Kolleru Lake's current location, formerly a lagoon at the shore but now deep inland, or the "Coastline of Emergence." Except for Visakhapatnam and Machilipatnam, this plain portion has a straight coast and severely lacks excellent harbours.

Tamil Nadu Plain: From Pulicat Lake to Kanyakumari, a distance of 675 kilometres, lies the Tamil Nadu Plain. It is 100 kilometres wide on average. The Cauvery delta, where the plain is 130 km broad, is the most significant feature of this plain. The Cauvery delta is considered the granary of South India due to its rich soil and extensive irrigation systems.

Significance of the Coastal Plains

• The coastal plains of India are largely covered by excellent soils that are ideal for agriculture.
• Large and small ports of Indian coastlines help in trade and investment.
• For coastal residents, fishing has become a necessary activity.
• Coastal and marine ecosystems, as well as a vast array of mangroves, coral reefs, estuaries, and lagoons, abound in India's coastal plains, providing good tourism options.
• Indian coastal lines are one of the primary forms of transportation, and oil exchanges are conducted exclusively over the ocean channel. 
• India's coastlines aid in exchanging and utilising such shorelines for our financial development. 
• The shoreline can be used to produce fish, pearls, and salt.
• The beach is also devoid of pollutants and can be used to saddle wind force.
• India advantages from a long beach front line by being located at the highest point of the Indian sea.