Indias latitudinal and longitudinal extent is 30°. North-South distance is 3214 km and east west distance is 2933 km. North lies in subtropical and warm temperate region and south lies in tropics.
It is the 7th largest country with 3.28 million sq km and 2.4% of worlds land surface and 17% of the population. It has 6100 km of coast in mainland and 7517 km along with the islands.
Gujarat has the longest coastline and Bangladesh shares the largest border with India. In all there are 7 countries not counting Tibet that India shares a border with.
Indira point in Nicobar Islands is the southernmost tip of India.
Physiography of India
Major Geological Formations of the Peninsular India (about 3600 million years ago)
The physical geography of India has four parts:
The northern mountain complex contains Himalayas, Trans Himalayas and Purvachal. Himalayas are in north, Hindukush and Sulaiman are in north west and Purvachal in east.
The Himalayas are true mountains. They are formed from the continent – continent plate collision. They have sediments of marine origin. It is not a single range but a series of ranges.
The Himalayas have three ranges namely great Himalayas [Himadri] , middle or lesser Himalayas [Himachal] and outer Himalayas [Shiwaliks].
Lower and gradual slope.
Higher and steep sudden slope.
Located on higher latitudes and so colder
Located on lower latitudes and so warmer
Don’t act as barrier to south west monsoon
Act as barrier to south west monsoon
Shiwaliks are farther
Shiwaliks are closer
TABLE 1: EASTERN AND WESTERN HIMALAYAS
The Himalayas are divided into five regions:
Debris, avalanches, landslides occur frequently in the Himalayas as they are techtnically active, made up of sedimentary, unconsolidated or semi consolidated rocks.
They have steep slopes.
Nilgiris slightly techtonically stable and have have hard rocks so land slides are less frequent. However direct rockfall is seen due to steep slopes, heavy rains and mechanical weathering due to temperature and escarpments.
When rivers are obstructed by mountains they spread out to form lakes. The lakes dry up when the rivers find paths through the mountains. These dried up lakes are called “duns”. They are found between great and middle Himalayas .
The Syntaxial Bends of the Himalayas
The mountains have same orogeny as the main Himalayas . From north to south the mountains are patkai, naga and mizo hills. The elevation decreases from north to south.
Patkai hills – border between Arunachal Pradesh and Myanmar.
Manipuri hills – border between Manipuri and Myanmar. Manipur has loktak lake and Mizoram has molassis basin which are soft unconsolidated deposits.
Andaman and Nicobar islands are extension of eastern Himalayas.
Importance of Himalayas
Youngest physiographic feature in India. Depositional flood plain created by Himalayan rivers like Indus, Ganga, Brahmaputra and Yamuna.
Densely populated with 30% of worlds population on 10% of worlds agricultural land.
Part of the northern plains:
North plains is divided into four parts:
It is covered by western ghats and eastern ghats and in the north by the central highlands. The Deccan traps were formed when Indian plate flowed over reunion island. The basaltic flow created layer over layer and it looks like steps. It is higher than northern plains.
Aravalli range: one of the oldest mountain range. It has sedimentary, metamorphosized rocks. Sabarmati from eastern side of Aravali merges into Arabian sea.
Vindhyan range: source of many north flowing rivers that meet Yamuna. It represents the water divide of central India. Mahi from north side of Vindhya also is a west flowing river.
Malawa plateau – between Aravalli and Vindhya range.
Satpuda range – has the Amarkantak plateau which is source of Narmada and son.
Narmada and tapti are old rift valleys. Worlds largest freshwater lakes are rift valleys.
They are extending from Maharashtra to Kerela. In Maharashtra they are steeper and higher. In Karnataka they are broader. In Kerela they are isolated hills with gaps that allow rain winds to pass through them.
Height of the Western ghats decreases from north to south.
The air parcel that passes over the hills retain energy but as they take longer the droplets precipitate into rain.
Anaimudi is the highest peak in the Deccan.
Discontinuous range but with lower heights in the mountains. Laterite soil is present. Coromandel coast lies between eastern Ghats and bay of Bengal.
Bay of Bengal has 572 islands out of which 2 main islets are richies and labyrinth island.
Andaman and Nicobar are separated by the 10° channel and Lakshadweep by 11° channel. Barren island in Nicobar is india’s only active volcano.
They are not a part of the western or eastern ghats. From north to south the hills are:
Nilgiri, Palani, Anamalai and Cardamom. Palghat pass between Nilgiri and Anamalai hills.
Nallamala, Javadi too are hill ranges in the south but above the above hills.
The western and the eastern ghats meet at Nilgiri hills.
Q.Consider the following pairs :
Medieval Indian State : Present Region
1. Champaka : Central India
2. Durgara : Jammu
3. Kuluta : Malabar
Which of the above pairs is/are correctly matched? (UPSC CSAT 2015)
A.1 and 2
C.1 and 3
Ans . B
The ninth century saw the rise of a number of hill states in the Himalayas, some of which maintained their identity until recent years, despite their wars with each other and the frequent raids from the men of the plains.
States such as Champaka (Chamba – Himachal Pradesh), Durgara (Jammu), Trigarta (jalandhar), Kuluta (Kulu – Himachal pradesh), Kumaon and Garhwal managed to remain outside the main areas of conflict in the northern plains.
Q.Consider the following rivers :
Which of the above are tributaries of Godavari? (UPSC CSAT 2015)
A.1,2 and 3
B.2,3 and 4
C.1,2 and 4
D.2 and 3 only
Ans . D
Left tributaries: Purna, Pranahita, Indravati, Sabari, Taliperu, Wainganga, Penganga, Wardha, Dudhana
Right tributaries: Pravara, Manjira, Pedda Vagu, Manair, Kinnerasani
Q1:Indias latitudinal and longitudinal extent is
Q2:State that has the longest coastline
Q3:Which is true
1.Khadar is more fertile
2.Bangar has calcerous formations
Q4: Which is true?
1.Worlds largest freshwater lakes are rift valleys.
2.Height of the Western ghats decreases from north to south.
Q5:Southern hills of India from north to south are
1.Nilgiri, Palani, Anamalai and Cardamom
2.Nilgiri, Anamalai, Palani, and Cardamom
3.Palani, Anamalai and Nilgiri, Cardamom
4.Anamalai and Cardamom, Nilgiri, Palani,