Q: Why is India’s north-south distance (3214 km) more than the east-west distance (2933), though both latitudinal and longitudinal extent of India is about 30 degree?
A: This is because the distance between the longitudes decreases near the pole whereas the distances between latitudes remain the same everywhere.
There is a general convention to select the standard time zone meridian in multiples of 7o30’ of longitude. There are 24 time zones on earth, each 15 degree apart.
USA uses multiple time zone system (7 time zones)
India has the longest international boundary with Bangladesh.
Tropic of Cancer passes through the following 8 states
Gujarat has the longest coast line.
UP borders the maximum number of states: 8
- Highest: UP> Maha> Bihar > WB
- Lowest: Sikkim< Mizoram < Arunachal < Goa
- Highest: Rajasthan>MP> Maha>>Andhra
- Lowest: Goa<Sikkim<Tripura<Nagaland<Mizoram
Three Geological divisions:
- The peninsular block
- The Himalayas and other Peninsular Mountains
- Indo-Ganga-Brahmaputra Plain
- Peninsualar block is made of gneisses (metamorphic) and granites (igneous).
Six physiographic divisions:
- The Northern and North-eastern Mountains
- The Northern Plain
- The Peninsular Plateau
- The Indian Desert
- The Coastal Plains
- The Islands
Northern and North-Eastern Mountains
Approximate length of the Great Himalayan range: 2500 KM. Width: 160-400 KM
Impact of Himalayas on the climate of India?
It can be divided into five sub-divisions:
- Kashmir (or Northwestern) Himalayas
- Himachal and Uttaranchal Himalayas
- Darjeeling and Sikkim Himalayas
- Arunachal Himalayas
- Eastern Hills and Mountains
Ranges: Karakoram, Ladhakh, Zaskar, Pir Pinjal
Glaciers: Baltoro, Siachen
Passes: Zoji La (Great Himalayas), Banihal (Pir Pinjal), Photu La (Zaskar) and Khardung La (Ladakh)
Lakes: (freshwater) Dal and Wular; (saltwater) Pangong Tso and Tso Moriri
Pilgrimage: Vaishno Devi, Amarnath Cave, Charar-e-Sharif
They are also famous for Karewa formations which are useful for the cultivation of Zafran (a local variety of Saffron). Karewas are the thick deposits of glacial clay and other materials embedded with moraines.
Kashmir is located on the banks of Jhelum river.
Meanders is a typical feature associated with the rivers in this region.
In South, there are longitudinal valleys called duns; Jammu dun and Pathankot dun
Himachal and Uttarakhand Himalayas
Lies between rivers Ravi and Kali
Drained by two major river systems: Indus and Ganga
Northernmost part is an extension of the Ladakh desert, lies in Spiti.
Ranges: Great Himalayan Range, Lesser Himalayas (Dhaoladhar in HP and Nagtibha in Uttarakhand), Shivalik range
Pilgrimage: Gangotri, Yamunotri, Kedarnath, Badrinath, Hemkund Sahib and the five famous prayags (Refer to Panch Prayag)
Famous for hill stations: Dharamshala, Mussoorie, Shimla, Kaosani; Cantt.: Kasauli, Almora, Lansdowne, Ranikhet
The important distinguishing features of this area are the ‘Shivalik’ and ‘Dun formations’.
Important duns: Chandigarh-Kalka, Nalagarh, Dehra, Harike, Kota
Dehradun is the largest of all duns: Length – 35-45 KM, Width: 22-25 KM
Inhabited with the Bhotia tribe. They migrate to higher reaches (Bugyals) in summer and return to the valleys during winters.
Darjeeling and Sikkim Himalayas
Between Nepal Himalayas and Bhutan Himalayas.
Fast flowing rivers such as Tista
Has a mixed population of Nepalis, Bengalis and tribals from Central India.
Importance: Due to the moderate slope, it is best suited for tea plantations. <India produces about 26 pc of tea in the world; second after China. Also, accounts for 12 pc of tea exports; fourth in the world.>
Duar formations are peculiar to this region.
From Bhutan Himalayas to Diphu pass in the east.
Direction: Southwest to Northeast
Peaks: Kangtu and Namya Barwa
Rivers: Brahmaputra, Kameng, Subansiri, Dihang, Dibang and Lohit.
These rivers are perennial and have the highest hydro-electric power potential in the country.
Tribes: Monpa, Daffla, Abor, Mishmi, Nishi and Nagas
These communities practice shifting cultivation known as Jhumming.
Eastern Hills and Mountains
Direction: North to South
Ranges: Patkai Bum, Naga hills, Manipur hills, Mizo or Lushai hills
These are low hills
Tribes practice Jhum cultivation
Rivers: Barak. Most of the Nagaland rivers form a tributary of Brahmaputra. Rivers in eastern Manipur are the tributaries of Chindwin, which in turn is a tributary of the Irrawady of Myanmar.
Loktak Lake: is an important lake in Manipur which is surrounded by mountains on all sides. It is the largest freshwater lake in northeastern India. Also called the only Floating Lake in the world due to floating masses of organic matter on it. It serves as a source for hydropower generation, irrigation and drinking water supply.
Keibul Kamjao National Park located in the Bishnupur district of Manipur is the only floating park in the world and is an integral part of the Loktak Lake. Home to the endangered Manipur Eld’s Deer or Brow-antlered Deer or Sangai or Dancing Deer.
Mizoram is also known as the ‘Molassis basin’ which is made up of soft unconsolidated deposits.
The Northern Plains
Formed by the alluvial deposits of rivers – Indus, Ganga and Brahmaputra.
Length: 3200 KM; Width: 150-300 KM
Three main zones:
- Alluvial Plains (Khadar and Bangar)
Narrow belt. 8-10 KM wide.
Paralllel to Shivalik at the break-up of the slope. Hence, streams and rivers deposit heavy rocks (and at times disappear) in this zone.
South of Bhabar. 10-20 KM wide.
Rivers re-emerge and create marshy and swampy conditions known as Tarai.
South of Tarai.
Features of mature stage of fluvial erosional and depositional landforms such as sand bars, meanders, ox-bow lakes and braided channels. Riverine islands in Brahmaputra.
Brahmaputra takes a turn an almost 90 degree turn at Dhubri (Assam) before entering Bangladesh.
Bounded by the Delhi ridge, Rajmahal Hills, Gir range and Cardamom hills.
Made up of a series of patland plateaus: Hazaribagh, Palamu, Ranchi, Malwa, Coimbatore, Karnataka etc.
One of the oldest and most stable landmass of India.
Physiographic Features: Tors, block mountains, rift valleys, spurs, bare rocky structures, hummocky hills and quartzite dykes offering natural sites for water storage.
Black soil in western and northwestern parts.
Bhima fault in this region has frequent seismic activity (Lathur earthquake)
NW part also has ravines and gorges: Chambal, Bhind and Morena.
Three broad regions:
- Deccan Plateau
- Central Highlands
- Northwestern Plateau
Bordered by Eastern Ghats, Satpura, Maikal range and Mahadeo hills
Important ranges: WG: Sahyadri, Nilgiri, Anaimalai and Caradamom hills; EG: Javadi hills, Palconda range, Nallamala Hills, Mahendragiri hills
EG and WG meet at Nilgiri hills.
Highest peak: Anaimudi (2695 m) on Anaimalai hills; Dodabetta (2637 m) on Nilgiri hills.
Rivers: Mahanadi, Godavari, Krishna, Kaveri etc.
Bounded by the Aravali and Satpura range.
Relic mountains, highly denuded and form discontinuous ranges.
Near Jaisalmer it is covered by the longitudinal sand ridges and crescent-shaped sand dunes called barchans.
Elevation: 700-1000 m
Banas, a tributary of Chambal, originates in the Aravalli. Other tributaries of Yamuna originate from the Vindhyan and Kaimur ranges.
Minerals in Chotanagpur plateau.
Extension of the main Peninsular plateau.
Meghalaya and Karbi Anglong plateau.
Megahalaya plateau: Garo hills, Khasi hills and Jaintia hills (named after the tribals inhabiting the region)
Rich in minerals like coal, iron, sillimanite, limestone and uranium.
Receives maximum rainfall from SW monsoon. Hence, Meghalaya plateau has a highly eroded surface. Cherrapuni and Myswarnam.
Northwest of the Aravali hills
Dotted with longitudinal dunes and barchans.
Low rainfall: >150 mm per year Low vegetation cover
Evidence that this area was under the sea during the Mesozoic era.
Features: mushroom rocks, shifting dunes and oasis.
Rivers are ephemeral: Luni. Brackish lakes. Inland drainage.
- Western coastal plains
- Eastern Coastal Plains
Western Coastal Plains
Submerged coastal plain. Hence, a narrow belt. Narrow in middle and broader towards north and south.
Ports: Provides natural conditions for the development of ports and harbours due to submergence. Kandla, Mazagaon (Mumbai), JLN port Navha Sheva, Maramagao, Mangalore, Cochin etc.
Mumbai has the world’s largest natural harbour.
May be divided into: Kachchh and Kathiawar coast in Gujarat, Konkan coast, Goan coast and Malabar coast.
Rivers don’t form delta.
Kayals (Backwaters): Found in the Malabar coast. Used for fishing and inland navigation. Every year Nehru Trophy Vallamkali (boat race) is held in Punnamada Kayal in Kerala.
Eastern Coastal Plains
Emergent coast. Hence, less number of ports and harbours. Chennai, Vizag, Paradwip, Haldia.
Two major Divisions:
- Andaman and Nicobar
- Lakshwadeep & Minicoy
Andaman and Nicobar
Two major island groups: Ritchie’s archipelago and the Labrynth island.
The group is divided into: Andaman in the North and Nicobar in the South.
Andaman and Nicobar separated by the Ten Degree channel.
Peaks: Saddle Peak (N.Andaman – 738 m), Mt. Diavolo (Middle Andaman – 515 m), Mt. Koyob (S Andaman – 460 m) and Mt. Thuiller (Great Nicobar – 642 m)
Coral deposits found
Convectional rainfalls and equatorial type of vegetation.
Lakshadweep and Minicoy
Entire group built of coral deposits.
Total of 36 islands of which 11 are inhabited.
Minicoy is the largest island
Separated by the 9 Degree Channel, north of which is the Amini Island and to the south Canannore island.
These islands have storm beaches consisting of unconsolidated pebbles, shingles, cobbles and boulders.
Drainage: Flow of water through well-defined channels. Network of such channels is called a drainage system .
Drainage basin: An area drained by a river and its tributaries.
Watershed: Boundary line separating one drainage basin from other.
River basins are larger watersheds.
Drainage pattern of an area depends on the geological time period, nature and structure of rocks, topography, rocks, slope, amount of water and periodicity of flow.
Important drainage patterns:
- Dendritic: Resembling the branches of a tree. Eg. Northern Plain rivers
- Radial: Originate from a hill and flow in all directions. Eg. Rivers in Amarkantak
- Trellis: Primary tributaries parallel to each other and secondary tributaries join them at right angles.
- Centripetal: Rivers discharge waters from all directions in a lake or depression
A river drains the water collected from a specific area, which is called its catchment area.
Nearly 77 pc of drainage is towards the Bay of Bengal while about 23 pc is towards the Arabian Sea.
The Himalayan Drainage System
Mainly includes the Ganga, Indus and Brahmaputra river basins.
Over the plains, rivers of this system change the course often. River Kosi is also known as the ‘sorrow of Bihar’ due to flooding by its frequent change of course by deposition of sediments.
Geologists believe that a mighty river called Shivalik or Indo-Brahma traversed the entire length of the Himalayas some 5-24 million years ago. Over time this got dismembered into the present three major river systems.
The Indus System
Indus river originates from a glacier near Bokhar Chu in Tibet in the Kailash Mountain range. Known as Singi Khamban (Lion’s mouth) in Tibet. It forms a spectacular gorge near Gilgit in J&K. Enters Pakistan near Chillar in the Dardistan region. Flows only through the Leh distt of J&K.
Smaller tributaries: Shyok, Gilgit, Zaskar, Nubra, Hunza, Shigar, Gasting, Dras. On right bank: Kabul river, Khurram, Tochi, Gomal, Viboa and hte Sangar.
Major tributaries: Satluj, Beas, Ravi, Chenab, Jhelum
|Jhelum||Origin: Verinag at foot of Pir Pinjal.
Flows through Srinagar and the Wular lake. Joins Chenab near Jhang in Pakistan
|Chenab||Origin: Two streams (Chandra and Bhaga) which join at Tandi near Keylong in HP.
Largest tributary of Indus. Aka Chandrabhaga. Flows for 1180 KM before entering Pakistan
|Ravi||Origin: Kullu hills of HP near Rohtang Pass. Enters Pakistan and joins Chenab near Sarai Sidhu|
|Beas||Origin: Beas Kund near Rohtang pass.
Forms gorges at Kati and Largi in the Dhaoladhar range. Meets Satluj near Harike.
|Satluj||Origin: Rakas lake near Mansarowar in Tibet. Known as Langchen Khambab in Tibet.
Enters India at Ropar. Antecedent river. Bhakra Nangal Project is on this river.
The Ganga System
It is the largest river system in India.
Ganga rises in the Gangotri glacier near Gaumukh in the Uttarkashi district. Here it is known as the Bhagirathi. At Devprayag, Bhagirathi meets Alaknanda and is known as Ganga hereafter.
Dhauli and Vishnu Ganga meet to form Alaknanda
|Alaknanda||Origin: Satopanth glacier above Badrinath. Consists of Dhauli and Vishnu Ganga.|
|Yamuna||Origin: Yamnotri glacier on Banderpunch range. Joins Ganga at Prayag (Allahabad).
RBT: Chambal, Sind, Betwa, Ken
LBT: Hindan, Rind, Sengar, Varuna.
|Chambal||Origin: Mhow in Malwa plateau.
Gandhi Sagar dam, Rana Pratap Sagar dam and Jawahar Sagar dam.
Famour for Chambal ravines.
|Gandak||Origin: In Nepal between Dhaulgiri and Mt. Everest. Enters Ganga plain in Champaran and joins Ganga at Sonpur near Patna.
Two streams: Kaliganfak and Trishulganga.
|Ghaghra||Origin: Glaciers of Mapchachungo
Tributaries: Tila, Seti and Beri
Deep gorge at Shishpani
Sarda (Kali) joint it and meet Ganga at Chhapra.
|Kosi||Origin: North of Mt. Everest in Tibet.
Tributaties: Son Kosi, Tamur Kosi, Arun
Changes course often. Sorrow of Bihar.
Ganga enters the plains at Haridwar.
Left Bank tributaries (LBT): Ramganga, Gomati, Ghaghara, Gandak, Kosi and Mahananda.
Right Bank tributaries (RBT): Son
Discharges into Bay of Bengal near Sagar island.