Coastal Plains of India
Location: The coastal plains of India are located along the Arabian Sea coast in the west and along the Bay of Bengal coast in the east. According to their location to the east or west of the peninsular, they are called:
- East coastal plain, and,
- West coastal plain.
East Coastal Plain
This east coastal plain begins from the north with the plains formed by the Subarnarekha River to extend to the south till Kanyakumari. It thus stretches for nearly 1500 km, with nearly a width of 100 km. to the east of this plain lies the extensive blue waters of the Bay of Bengal and to the west of the plain lies the remnants of Eastern Ghat hills. Compared to the Western Coastal Plain, the East Coastal Plain is wider. The deltas of the Mahanadi, Godavari, Krishna and Kaveri rivers have formed nearly 25% of the area of this plain. The soil of the deltas is very fertile therefore agriculture is very productive. Specially and delta of the river Krishna is very fertile and is known as the ‘Granary of South India’.
The East Coastal Plain can be physio-graphically subdivided into:
- Coromandel Coast, and,
- North Sircar Coast,
While according to states it can be divided into:
- Orissa or Utkal coastal plain,
- Andhrea coastal plain, and,
- Tamil Nadu coastal plain.
The plain south of the mouth of the Krishna is called Coromandel Coast and the part of the East coast lying to the north of the mouth of the Krishna is called the North Sircar Coastal plain.
The Sand dunes Lagoons in the East Coastal plain: The East coastal plains show the presence of many sand dunes, lagoons and varieties of marshland. The sand dunes vary between 1 – 4 km in length and 60-65 meters in height. Between the sand dunes and the coast lie the lagoons. They are connected to the sea very slightly, e.g. – Chilka Lake in the Utkal coast, Kolleru and Pulicat lakes in the Andhra coast. The rocket is launching and satellite launching center of India, The Space Research Centre, is located in the island of Sriharikota lying in the Pulicat Lake. The sand dunes along the Tamil Coast are called ‘Theris’ by the locals. Besides these, highlands or Tillas are also seen along the East coast.
West Coastal Plain
It stretches from the Rann of Kachchh in the north to Kanyakumari in the South. To the East it is bounded by the steep slopes of the Western Ghat and to the west lays the Arabian Sea. Compared to the East Coastal Plain, this West coastal plain is narrower. The west coastal plain becomes narrower gradually from the Kachchh coast to Kanyakumari, where it is narrower unlike the East coastal plain with large rivers and their wide mouths or large deltas, the west coast has short river coming down swiftly from the western slopes of the Western Ghat, the draining into the Arabian Sea without forming any deltas.
Subdivisions of the West Coastal Plain:
1. The Coastal Plains of Gujarat: This forms the north portion of the west coast. It is quite wide. The lowland in the Kachchh region from marshes and are called Rann. In the monsoon this entire Rann region lies under water. In the past, the Gulf of Khambhat extended into the Rann of Kachchh and the Kathiawar Peninsula was an island.
2. The Coastal Plain of the Konkan: From Daman in the north to Goa in the south lays the Konkan Coastal Plain. This plain extends for 500 km but is very narrow and broken. No other coastal plain of India is so narrow. Most of the plain is formed of rock. Through the northern part of this coast flows the Baitarani River.
3. The Coastal Plains of Karnataka: South of the Konkan coast starts the coastal plains of Karnataka between Goa in the north and Mangalore in the south, for 225 km. Though this coastal plain is narrow it is wider near Mangalore 70 km. At many places along the coast the plain is sandy and at some places the Western Ghat reaches the sea. To the east of this plain lies the highest waterfall of India, called Jog or Gersoppa which falls across the Sharavati River. The height of the fall is 275 meters.
4. The Coastal Plains of Malabar: The extreme southern part of the west coal plain lies in the state of Kerala and is called the Malabar Coast. Compared to the Konkan and Karnataka Coastal plains this is the widest at 25 km on average.
5. Lagoons: There are many sand dunes, lakes or lagoons along the Malabar Coast. The local people call these lagoons Kayal e.g. the 80 km long Vembanad Kayall near Kochi and the Ashtamudi Kayal near Kollan (Quilon) are famous.
Importance of coastal plains of India
- The fertile plains along the coast produce large amounts of rice, sugarcane, coconut, various spices etc.
- Through the ports of Mumbai, Chennai, Mormugao, Kochi (Cochin) etc most of the international trade of India is conducted.
- Large amount of salt is produced from the northern part of the west coastal plain from sea water.
- Mineral Oil and Natural Gas is either being extracted or possibility of the resources being present is very probable in the river valleys of Krishna, Godavari and Kauvery.
- Due to the suitable environment in the coastal regions population density is very high.