Physiography of India - Part 7

PHYSIOGRAPHY OF INDIA - PART 7

REGION 28, 22 & 27: WESTERN & EASTERN GHATS & SOUTHERN HILL COMPLEX

Western Ghats
•    Form a continuous barrier from north to south, almost parallel to the Arabian Sea. General altitude is 900-1100 m. These are higher in their southern part
•    Known as Sahyadri in Maharashtra and Karnataka, Nilgiris in T.N., Anaimalai and
Palni-Cardamom Hills in Kerala and Tamil Nadu.
•    Collectively Nilgiris, Anamalai Hills & Palni-Cardamom Hills form Southern Hills Complex.
•    Nilgiris is the meeting point of Western Ghats, Eastern Ghats and Southern Hill Complex. Doda Beta (2637m) is the highest peak of Nilgiris. Udagamandalam (ooty) is a hill station located in Nilgiris (Tamil Nadu). Temperate forests called Sholas are found here.
•    Anai Mudi (2,695m) is the highest peak of Western Ghats. It is located in Anamalai Hills
and falls in Kerala.
•    Famous hill station of Kodaikanal (T.N) lies in Palni Hills. The source of Periyar River lies in Cardamom Hills. Periyar Lake is also situated here.

Eastern Ghats
•    Form a discontinuous line of hills parallel to E.Coast
•    Known by different names at different places –
o    Northern Circars in north of Godavari
o    Palkonda & Nallamala between Godavari & Palar Rivers
o    Shevaroy & Javadi as T.N hills
•    As opposed to Western Ghats, E. Ghats are higher in northern part. Mahendra Giri
(1501m) is the highest peak of E.Ghats, lying in Orissa.

Differences B/W Western Ghats & Eastern Ghats

Western Ghats
Higher average elevation than E. Ghats. Higher in Southern part
Source of many rivers. Act as a water divide
High rainfall (>200cm). higher in south
Greater HEP potential. Many waterfalls
Water falls in Western Ghats

Eastern Ghats
Higher in northern part
Not a source of any river
Less rainfall (<200cm). higher in north
Lesser potential
Water falls in Eastern Ghats

REGION 19, 20, 21, 29, 30 AND 31: COASTAL PLAINS

West Coastal Plain
•    Extend from Gujarat to Kerala.
•    Known as Konkan in the north (Daman to Goa), Kanara in Karnataka and Malabar in the Kerala.
•    Plains are narrower in the north (Goa & Karnataka) and wider in south (Kerala)
•    Jog Falls/ Gersoppa Falls (on R. Sharavati) on Karnataka Coast are the Highest in India.
•    In Kerala, coast has salt water lakes called Lagoons or Backwaters or Kayals. Important Lakes here are Ashtamudi and Vembanad
•    Lowlands during rains merge together to form Patlas; are used for cultivation

East Coastal Plains
•    Coastal strip along Bay of Bengal is broader as compared to the western coast.
•    Known as Utkal Plains (in Orissa); wide and deltaic (Mahanadi & Brahamani delta). Chilka
lagoon is located here
•    Andhra Plains: Deltaic (Godavari & Krishna delta) in middle. Kolleru lake lies here
•    Coromandal Coast (Tamil Nadu) in south; Deltaic (Cauvery delta); Pulicat lake lies here

Differences B/W West Coastal Plains & East Coastal Plains

Western Coastal Plains
Formed by submergence of western side of Western Ghats. Retrograded coastline
Less in width due to subsisdence. Continental Shelf is wide because of the same reason.
Rivers are smaller, swift and more erosive. Form estuaries.
Rainfall: 200-400 cm (SW Monsoon)
Less prone to cyclones
Not prone to floods except Narmada estuary because of swiftness and small lengths of rivers
More contribution to marine food
Prospects of Wave Energy
More no. of Natural Harbours
Ports important for import purposes

Eastern Coastal Plains
Formed by alluvium brought by rivers like Mahanadi, Godavari, Krishna & Cauvery. Prograded coastline
Wider coast & narrower shelf due to emergence
Rivers are longer, gradual and less erosive. Form deltas.
Rainfall: 100-200 cm (SW & NE Monsoon)
More prone to cyclones
Prone to floods because of gradual lengths, deltaic formations & long lengths of rivers
Less contribution
Prospects of OTEC (Ocean Thermal Energy Conversion)
Lesser no.
Ports important for export purposes

REGION 32, 33: ISLAND GROUPS

 
Lakshadweep Islands
•    Extend from 8ºN - 12ºN. Consists of 30 small islands, only 10 of which are populated.
•    Population consists of Moppilas (Muslims) from Kerala
•    Coral origin (made up by the organic activity of micro-organisms called coral polyps)
•    Among Lakshadweep islands, some islands are horse-shoe shaped called Atolls.
•    Lakshadweep Group consists of 2 sub-groups:
o    Amandivi Islands -    North of 11o N Channel
o    Cannanore Islands -    South of 11o N Channel
•    Minicoy Islands lie to the extreme south

Andaman and Nicobar Islands
•    Extend from 6º 39’N - 13º 34’N
•    Consist of two groups – Andaman Group (Great & Little Andaman) – 204 islands, and Nicobar Group (Car, Little and Great) – 19 islands
•    Continent in origin. They are submerged parts of mountain range called Arkan Yoma
(Mayanmar).
•    Some of them are of volcanic origin and only active volcano of India is located on these islands (Barren Island). Narcondam is the extinct volcanic island.
•    10º channel separates Andaman (Little) from Nicobar
•    Little Andaman is separated from Great Andaman by Duncan passage
•    Great Nicobar is the Largest Island in the group
•    Saddle Peak in North Andaman – highest peak
•    Car Nicobar encircled by a Fringing Reef
•    Prone to earthquakes and tsunamis
•    Main Tribes here are Great Andamanese, Onges, Senthelese, Jarawas and Shompens
•    High potential for wave power & OTEC