Of the total coastline of India (7517 km), that of the peninsula is 6100 km between the peninsular plateau and the sea. The peninsular plateau of India is flanked by narrow coastal plains of varied width from north to south.
On the basis of the location and active geomorphologic processes, these can be broadly divided into two parts:
- The western coastal plains
- The eastern coastal plains.
We now take them up one by one:
The Western Coastal Plain
1. Extent: The Western Coastal Plains are a thin strip of coastal plains with a width of 50 kms between the Arabian Sea and the Western Ghats.
2. Subdivisions: Extending from the Gujarat coast in the north to the Kerala coast in the south, the western coast may be divided into following divisions:
- Kachchh and Kathiawar coast in Gujarat,
- Konkan coast in Maharashtra,
- Goan Coast in Karnataka, and
- Malabar coast in Kerala
Note: Kutch and Kathiawar, though an extension of Peninsular plateau (because Kathiawar is made of the Deccan Lava and there are tertiary rocks in the Kutch area), they are still treated as an integral part of the Western Coastal Plains as they are now levelled down.
3. A coastline of submergence: The western coastal plains are an example of submerged coastal plain. It is believed that the city of Dwaraka which was once a part of the Indian mainland situated along the west coast is submerged under water.
4. Characteristic Features:
- The western coastal plains are narrow in the middle and get broader towards north and south. Except for the Kachchh and Kathiawar coastal region, these are narrower than their eastern counterpart.
- The coast is straight and affected by the South-West Monsoon winds over a period of six months. The western coastal plains are thus wetter than their eastern counterpart.
- The western coast being more indented than the eastern coast provides natural conditions for the development of ports and harbours. Kandla, Mazagaon, JLN port Navha Sheva, Marmagao, Mangalore, Cochin, etc. are some of the important natural ports located along the west coast.
- The western coastal plains are dotted with a large number of coves (a very small bay), creeks (a narrow, sheltered waterway such as an inlet in a shoreline or channel in a marsh) and a few estuaries. The estuaries, of the Narmada and the Tapi are the major ones.
- The rivers flowing through this coastal plain do not form any delta. Many small rivers descend from the Western Ghats making a chain of waterfalls.
- The Kayals – The Malabar coast has a distinguishing feature in the form of ‘Kayals’ (backwaters). These backwaters are the shallow lagoons or the inlets of the sea and lie parallel to the coastline. These are used for fishing, inland navigation and are important tourist spots. The largest of these lagoons is the Vembanad lake. Kochi is situated on its opening into the sea.
The Eastern Coastal Plain
1. Extent: The Eastern Coastal Plains is a strip of coastal plain with a width of 100 – 130 kms between the Bay of Bengal and the Eastern Ghats
2. Subdivisions: It can be divided into two parts:
- Northern Circar: The northern part between Mahanadi and Krishna rivers. Additionally, the coastal tract of Odisha is called the Utkal plains.
- Coromandel Coast (or Payan Ghat): The southern part between Krishna and Kaveri rivers.
3. A coastline of emergence: The eastern coastal plain is broader and is an example of an emergent coast.
4. Characteristic features:
- The eastern coastal plains are wider and drier resulting in shifting sand dunes on its plains.
- There are well-developed deltas here, formed by the rivers flowing eastward in to the Bay of Bengal. These include the deltas of the Mahanadi, the Godavari, the Krishna and the Kaveri.
- Because of its emergent nature, it has less number of ports and harbours. The continental shelf extends up to 500 km into the sea, which makes it difficult for the development of good ports and harbours.
- Chilika lake is an important feature along the eastern coast. It is the largest salt water lake in India.
Significance of the Coastal Plains region:
- These plains are agriculturally very productive. The western coast grows specialized tropical crops while eastern coasts witnessed a green revolution in rice.
- The delta regions of eastern coastal plains have a good network of canals across the river tributaries.
- Coastal plains are a source of salt, monazite (used for nuclear power) and mineral oil and gas as well as centres of fisheries.
- Although lacking in adequate natural harbours, with a number of major and minor ports, coastal plains are centres of commerce and have attracted dense human settlements.
- The coastal regions of India are noted for tourist centres, fishing and salt making.
Now that we are done with this part, let’s try to attempt some questions from the past UPSC examinations:
Question: Assertion (A): The eastern coast of India produces more rice than the western coast.
Reason (R): The eastern coast receives more rainfall than the western coast.
Ans. C (Assertion is right but reason is wrong)
Question: Assess the significance of coastal regions in the economic development of India. (2009/ 15 marks)