Coastal plains of India refer to the low flat areas which are situated adjacent to a water body, usually the sea. Coastal plains are characterised by raised beaches and wave-cut platforms above the high water mark. It signifies that these coastal plains of India are basically the emerged floors of the seas adjacent to the land. The Great Indian Peninsular Plateau
is fringed with narrow Coastal Plains. After the emergence of these lowlands, fluctuations in sea level, though limited to small areas, have brought about some changes in the general surface features of the littoral. The Deccan plateau
has a coastal strip in the east and west. Coastal plains are generally separated from the interior land and have less vegetation in comparison. The coastal plains of India are rather extensive regions that significantly contribute to the physiographic aspect of the region.
Types of Coastal plains of India
Coastal Plains of India are divided into two basic types and these are:
* Eastern Coastal Plains runs from Tamil Nadu
to West Bengal
in the east.
* Western Coastal Plains extends from Gujarat
in the west to Maharashtra
The two types of Indian Coastal Plains are discussed below in details:
Eastern Coastal Plain
The Eastern Coastal plain lies between West Bengal and Tamil Nadu. It stretches between the Bay of Bengal
and the Eastern Ghats of India. 130 km is the average width of these plains. The region receives adequate rainfall between 40 to 120 inches, from Southwest and Northeast monsoons and has an average temperature above 30 degrees Celsius and high humidity. The Northern Circars, amidst Krishna River and Mahanadi River
is the northern part. While the southern part, the Coromandel Coast
, runs between Kaveri River
and Krishna River. These plains have 6 regions:
* Southern Andhra Pradesh
* Kanyakumari Coast,
* Mahanadi Delta,
* Sandy Coastal regions,
* Krishna Godavari deltas and
* Coromandel Coast
Western Coastal Plain
The Western Coastal plain lies between Kerala
and stretches from the Arabian Sea
to the Western Ghats. 50 km is the average width of these plains, much less than its eastern counterpart. These plains feature plentiful rivers and backwaters which result in forming estuaries. The Gulf of Kutch
and the Gulf of Khambat lie on the northern part. The Western Coastal Plain is separated into three major parts the Malabar Coast, the Konkan coast and the Gujarat Coast.
The Coastal plain in the surrounding area of the Palghat
town and in the south of Kerala is relatively broad. In places, it expands to a width of near about 96 km. Off-shore bars have enclosed lagoons which run parallel to the coast in southern part of Kerala. These lagoons, also known as Kayals, receive water of a large number of rivers before discharging that to the sea with which they are connected by narrow openings. Interestingly, formation of lagoons and off-shore bars indicate that there has been a minor emergence of southern coastal plain not in the remote past. Western coastal plain widens from the states of Gujarat to Kerala. The coastal zone in the west along the Arabian Sea is called as Malabar in the south of Goa and Konkan in the north of Goa
Further, there are several estuaries, the main ones being those of the Narmada River
and Tapti River
. It is blessed with cavernous natural harbours like Mumbai and Marmagao. Towards the south, the coastal plains of India are combined with salt water lakes that are called Lagoons. There are also sand bars or spits in their mouths. The coast is celebrated for its tranquil backwaters. Moreover, the coastal zone along the Bay of Bengal
is extensive and differs from the western strip. The coastal strip, if not for the deltas, is rocky and extremely cut apart by small, but fast flowing rivers. The eastern coastal plain is wide in Tamil Nadu where its width is around 100 to 120 km. Eastern coastal plains have 3 main divisions-
* Utkal Plains,
* Andhra Plains and
* Tamil Nadu Plains.
The Rann of Kutch, the peninsulas of Kutch and Kathiawar and the Gujarat Plain stand out as major physiographic regions. The Rann of Kutch lies to the north of Kutch. Previously a gulf and now a vast desolate plain it has been formed due to the deposition of silt. Kutch lies to the south of Gulf of Kutch
. It was once an island. It is a dry area generally broad sandy terrain along the coastal plains.
Kathiawar is located to the south of Kutch. It is hilly in the central part and a rolling plain below an elevation of 200 m. Tapti River
, Narmada River
, Sabarmati River
and Mahi River
deposit huge load of sediments in the Gulf of Cambay. As a result, a broad fertile area has come into existence at the north of Daman. This plain extending towards north up to the Aravalli Mountain Ranges
is known as the Gujarat Plain. The west coastal plains south of Surat are drained by small rivers which become torrents during the monsoon rainy season.
Coastal plains of Goa and Konkan south of Mumbai
are marked with low hills separated by river courses which end in streams near the sea.