Coastline of India

• India has a coastline of 7516.6 km (6100 km of mainland coastline + coastline of 1197 Indian islands) touching 13 states and union territories.
• The straight and regular coastline of India is the result of faulting of the Gondwana land during the cretaceous period.
• As such the coast of India does not offer many sites for good natural harbour.
• Indented coastline of Europe provide good natural harbour whereas African and Indian coastlines are not indented.
• The Bay of Bengal and Arabian Sea came into being during cretaceous period for early tertiary period after the disintegration of Gondwana land.

East coast of India

• • Lies between Eastern Ghats and bay of Bengal
  • Extends from Ganga delta to Kanyakumari.
  • Marked by delta of rivers like Mahanadi, Godavari, Krishna and Kaveri.
  • Chilka Lake and the Pulicat Lake are important geographical features of east coast.
  • Regional name of east coast of India are —
    • • Orissa – Utkal coast.
      • From the Southern limit of Utkal coast stretches Andhra coast.
      • In the south of Andhra coast plains is the Tamil Nadu coast.
      • Tamil Nadu coast and part of Andhra coast together are known as Coromandel Coast or Payan coast.

West coast of India

• • Extends from gulf of Khambhat in the north to Cape Comorian or Kanyakumari.
  • Starting from north to south is divided into —
    • • Konkan coast
      • Karnataka coast
      • Kerala coast
  • Made up of alluvium brought down by short streams originating from Western Ghats.
  • It is dotted with large number of coves, creek and few estuaries.
  • The estuaries of Narmada and Tapi are major one.
  • The Kerala coast or Malabar Coast has some lakes, lagoons and backwaters. The largest being the Vembanad Lake.
  • Regional names of Western coast of India are —
    • • Konkan coast – Maharashtra coast and Goa coast
      • Malabar Coast – Kerala and Karnataka coast.

Coastlines

• • The boundary between the coast and the shore is known as coastline.
  • Coastline can be divided into –

1. 1. 1. 1. Coastline of emergence
         2. Coastline of submergence

Coastline of emergence and submergence

• • • Coastline of emergence is formed by and upliftment of the land or by lowering of sea level. Coastline of submergence is exactly opposite to it.
    • Bars, Spits, Lagoons, Salt marshes, beaches, sea cliffs and Arches are typical features of emergence.
    • The east coast of India especially its south eastern part (Tamil Nadu coast) appears to be a coastline of emergence.
    • The best coastline of India is both emergent and submergent.
    • The northern portion on the coast is submerged as a result of faulting and Southern ocean that is k love what is an example of emergent coast.
      • • • Coromandel coast (Tamilnadu) coastline of emergence
          • Malabar coast (Kerala coast) the line of emergence
          • Konkan coast (Maharashtra and Goa coast) coastline of submergence.

Western Coastal Plains of India

• • The Western Coastal Plains of India extends from Rann of Kutch in north to Kanyakumari in south.
  • There are narrow plains with an average width of about 65 km.

1. Kutch And Kathiawar Region

• • • Kutch and Kathiawar region, though an extension of Peninsular plateau (because Kathiawar is made up of Deccan Lava and there are tertiary rocks in Kutch region) they are still treated as integral part of Western coastal plain.
    • The Kutch Peninsula was an island surrounded by seas and lagoons. These seas and lagoons were later filled by sentiment brought by the Indus River which used to flow through this area. Lack of rain in recent time has turned the area into an arid or semi-arid land.
    • Salts soaked plain to the north of Kutch is great Rann. Its Southern continuation known as little Rann lies on coast of and south east of Kutch.
    • The Kathiawar Peninsular lies to the south of Kutch. The central part is highland of Mandav Hills from which a small stream radiates in all directions. Mt. Girnar (1117 m) is the highest point in volcanic origin.
    • The Gir range is located in the southern part of the Kathiawar Peninsula. It is covered with dense forest and is famous as home of Gir lion.

2. Gujarat Plains

• • • The Gujarat Plains lies in the east of Kutch and Kathiawar and slopes towards west and South West.
    • Formed by the river Narmada, Tapi, Mahi and Sabarmati the plain includes the southern part of Gujarat and the coastal areas of Khambhat.
    • The Eastern part of this plain is fertile enough to support agriculture but the greater part near the coast is covered by wind-blown ‘loess’.

3. Konkan Plains

• • • The Konkan Plains lies south of Gujarat Plains extends from Daman to Goa, 50 to 80 km wide.
    • It has some features of marine erosion including cliffs, shoals, reefs and island in the Arabian Sea.
    • The Thane creek around Mumbai is an important embayment which provides an excellent natural harbour.

4. Karnataka Plains

• • • Extends from Goa to Mangalore.
    • It is a narrow plain with an average width of 30 to 50 km, the maximum being 50 km near Mangalore.
    • At some place the stream originates in the Western Ghats descending along the steep slopes and make waterfalls.
    • The Sharavathi river while descending over such a steep slope make an impression of waterfall known as the Jog fall which is 271 m high. (Highest waterfall of India)
    • Marine topography is quite marked on the coast.

5. Kerala Plains

• • • Also known as Malabar plains.
    • Between Mangalore and Kanyakumari.
    • Much wider than Karnataka plains. It is low lying plains.
    • Existence of lakes, lagoons, backwaters, spits etc. is significant characteristic of Kerala coast.
    • The backwater locally known as kayals are the shallow lagoons or inlets of the sea lying parallel to the coastlines.
    • Largest among these is the Vembanada Lake which is about 75 km long and 5 to 10 km wide and gives rise to a 55 km long is spit.

Characteristic of Western Coastal Plains

Extent

• • • Thin strip of coastal Plains with a width of 50 to 80 km between Arabian sea and Western Ghats
    • Extends from Rann of Kutch to Kanyakumari.

Subdivisions

• • • Extending from Gujarat coast to Kerala coast in the south the Western coast can be divided into-
      • • Kutch and Kathiawar region coast of Gujarat
        • Konkan coast in Maharashtra and Goa
        • Karnataka coast of Goan coast in Karnataka.
        • Malabar coast in Kerala

Features

• • • Narrow in middle and broad in North and South. Except for Kutch and Kathiawar region they are Narrower than their Eastern counterparts.
    • The coast is a straight and affected by the Southwest monsoon winds over a period of 6 month. The Western coastal Plains are wetter than their Eastern counterparts.
    • The Western coast be more indented then the eastern coast provides natural condition for the development of ports and harbours. Kandala, Mazgaon, JLN port, Navha Sheva, Marmagao, Mangalore, Cochin etc. awesome of important natural ports located along the coast.
    • The Western coastal Plains are dotted with a large number of Coves and creeks and few estuaries.
    • The river flowing through this coastal Plains do not form delta. Many small river decent from Western Ghat making a chain of waterfall.
    • The kayals – Malabar Coast has distinct feature of kayals. These backwater are the shallow lagoons or the inlets of seawater and lies parallel to the coastline. They are used to for fishing, inland navigation and are important tourist spot. The largest of these lagoons are Vembanada Lake, Kochi is situated on its opening in to sea.

Eastern Coastal Plains of India

• • Extending from Subarnarekha River along the West Bengal Orissa border to Kanyakumari.
  • Major part of the plain is formed as a result of the alluvial fillings of the littoral zone by The Rivers Mahanadi, Godavari, Krishna and Kaveri comprising some of the largest delta.
  • In contrast to West Bengal Plains, these are extensive Plains with width of 120 km.
  • This plain is also known as Northern circars between Mahanadi and Krishna rivers and Carnatic between Krishna and Kaveri River.

1. Utkal Plain

• • • Comprises coastal areas of Odisha and includes the Mahanadi delta.
    • Most prominent geographical feature is Chilka Lake.
    • Chilka Lake is biggest lake of country and its area varies between 780 sq. km in winter to 1144 sq. km in monsoon months.
    • South of Chilka Lake, low Hills dot the plains.

2. Andhra Plain

• • • South of Utkal plains extends up to Pulicat Lake. This lake is barred by long sand spit known as Sriharikota Island.
    • Most significant feature of the plain is the formation of delta by Godavari and Krishna.
    • Two delta have merged to each other and has formed a single physiographic unit.
    • The combined delta has advanced by about 35 km towards the sea in recent years.
    • This is clear from the present location of the Kolleru Lake which was once a Lagoon at the shore but now lies far away in land (coastline of emergence).
    • This plain has a straight coastline and badly lacks good harbour with exception of Visakhapatnam and Machilipatnam.

3. Tamil Nadu Plains

• • • Stretches from 675 km from Pulicat Lake to Kanyakumari along the coast of Tamil Nadu.
    • Average width – 100 km.
    • Most important feature of this plain is Cauvery delta where the plain is 130 km wide.

Characteristic of Eastern Coastal Plain

Extent

• • • Strip of coastal plain with a width of 100 to 130 km between Bay of Bengal and Eastern Ghat.
    • Extend from Subarnarekha River to Kanyakumari.

Subdivision

• • • It can be divided into two parts-
      • Northern circars- Northern part between Mahanadi and Krishna River. Additionally the coastal tract of Orissa is known as Utkal plains.
      • Coromandel Coast or Payan coast- Southern power between Krishna and Kaveri River.

Coastline of emergence

• • • Eastern coastline is broader and is an example of coastline of emergence

Features

• • • Wider and drier resulting in shifting of sand dunes on its plains.
    • There are well developed delta here, formed by rivers flowing eastward in the Bay of Bengal.
    • This includes delta of Mahanadi, Godavari, Krishna and Kaveri.
    • Because of emergent nature it has less number of ports and harbours. The continental shelf extends to 500 km into the sea which makes it difficult to develop good port and harbour.
    • Chilka Lake the largest saltwater lake of India is important feature of the eastern coast.

Significance of Coastal Plains of India

• • Large part of coastal plains of India is covered by fertile soil on which different crops are grown. Rice is major crop in this area.
  • Coconut trees grows all along the coast.
  • Entire length of the coast is dotted by big and small coastal ports which help in trading.
  • The sedimentary rocks of these plains are said to be containing large deposits of minerals and oil.
  • Send off Kerala coast have large quantity of monazite which is used for nuclear power.
  • Fishing is an important occupation of the people.
  • Low lying area of Gujarat are famous for Salt production.
  • Kerala backwater are important tourist destination.
  • Goa beaches and important tourist destination.

 

That’s it for this post on The Coastal Plains of India.

In the next post (Click here), we would study in detail The Islands of India.