Rajasthan Public Service Commission

Volume - 9

Indian Geography
 RAS
Volume – 9

Indian Geography
Page
S.No. Chapter Name
No.
1. Major Physical Features, Rivers and Lakes – World 1
 Mountains
 Plateaus
 Plains
 Deserts
 Rivers
 Important Rivers of the World
 Lakes
2. Volcanoes and Earthquakes 36
 Volcanoes
 Causes of Volcanism
 Types Of Volcanoes
 Earthquakes
 Causes Of Earthquakes
3. Earth and Geological Time Scale 49
 Motions of Earth
 Solstice
 Equinox
 Geological Time Scale
4. Types of Agriculture 56
 Types of Agricultural Revolution in India
 Cropping System and Cropping Pattern in India
 Types of Cropping patterns
 Farming Systems
 Cropping Seasons in India
5. Major Industrial Regions of the World 64
 Classification of Industries
 Factors affecting location of Industries
 World Industrial Regions
 World Industrial Problems
6. Major Physical Landforms, Rivers and Lakes 68
 Himalayan Mountains
 Sub Divisions of the Himalayas
 Important Passes of Himalayas
 Indian Drainage System
 Important lakes of India
7. Major Physiographic Divisions of India 109
 Great Plains of India
 Coastal Plains
 Peninsular Plateau
 Islands of India
8. Climate of India 133
 Seasons in India
 Factors Influencing Indian Climate
 Indian Monsoon
 Impact of Monsoons on Life in India
9. Natural Resources 152
 Water Resources of India
 Inter-State River Water Disputes
 Watershed Management
 Rainwater harvesting
 Natural Vegetation of India
 Soil types in India
 Problems of Indian soil
 Soil Conservation
10. Agriculture in India 174
 Important Crops of India
11. Rocks and Minerals in India 185
 Rock System of India
 Mineral Resources
12. Energy Resources 207
 Conventional Sources
 Non-conventional sources
13. Major Industrial Regions of India 224
 Mumbai-Pune Industrial Region
 Hugli Industrial Region
 Bangalore-Tamil Nadu Industrial Region
 Gujarat Industrial Region
 Chotanagpur Industrial Region
 Gurgaon-Delhi-Meerut Industrial Region
 Minor Industrial Regions
 Major Industries in India
14. Transportation in India 234
 Road Transport
 Rail Transport
 Ports and Waterways
 India’s International Trade
15. Population 250
 Demography of India
 The population of India by state (UTs not included)
 Population density (persons per sq. km) by state (UTs not included)
 Literacy Rates in India
 Fertility Rate in India (Number of children born per woman)
 Sex Ratio in India (not including UT’s)
16. Wildlife and Biodiversity 253
 Components of an Ecosystem
 Biodiversity
 Biodiversity Hotspots
 Biosphere Reserve
 Wildlife Conservation
 National Parks
17. Environment and Environmental issues 277
 Climate Change
 Climate Change in India
 Global Warming
 Ozone Depletion
 Indian Efforts to Counter Climate Change
 Global Efforts
––
1 Major Physical Features, Rivers
CHAPTER and Lakes – World
Landforms

Landforms of first order Landform of first order

 Continents  Oceans
Landforms of second order Landforms of second order
 Mountains  Continental shelf
 Plateaus  Continental slope
 Plains  Ocean basin
 Ocean deep

Landforms of third order Landform of third order

Peaks, cols, cirques, gorge, Island, coastline, shoreline, atoll,

Allvvial fan, floodplain, delta ocean ridges, coral reefs etc
Oxbow lakes, arate etc

Mountains
Classification of Mountains
1. On the basis of height
A. Low mountains: 700 -1,000 m.
B. Rough mountains: 1000 m - 1,500 m
C. Rugged mountains: 1,500 - 2,000 m.
D. High mountains: > 2,000 m.
2. On the basis of location
A. Continental mountains
a. Coastal mountains: Nearby Coasts.
 Examples: Applachians and Rockies (North America), Alpine (Europe), Western and Eastern Ghats
of India etc.
b. Inland mountains: On main landform
 Examples: Ural Mountains (Russia), Vosges and Black Forest block mountains (Europe),
Himalayas, Aravallis, Satpura etc. (India), Kunlun, Tienshan, Altai etc. (Asia) etc.
B. Oceanic mountains
a. Mostly below the water surface, some can be found above also.
b. Majorly on continental shelves and ocean floors.
c. Example: Mauna Kea volcanic mountain of Hawaii Island , Antilean Mountain system
3. On the basis of mode of formation
A. Circum-erosional or relict mountains:
● The remnants of old fold mountains

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 ● Formation: A result of denudation
● Eg: Vindhyachal ranges, Aravallis, Satpura, Eastern Ghats, Western Ghats etc.
B. Original or tectonic mountains:
● Formation: Due to tectonic forces
● These can be further divided into 4 types:
I. Folded Mountains
○ Formation: when two or more of Earth's tectonic plates are pushed together by compressive
forces generated by endogenetic forces of earth.
○ Location: Convergent plate Boundaries
○ Characteristics:
 Youngest mountain group.
 Fossils present.
 Concave slope on one side and convex slope on the opposite side.
 Earthquake prone
 Most numerous and the most significant.
 Have abundant mineral resources such as tin, copper, gold, and other metals.
 Area of volcanic activity.
○ Types:
 Young folded mountains:
 Least affected by denudation
 Eg: Rockies, andes, Alps, Himalayas.etc
 Mature folded mountains:
 Affected by denudation.
 Characterized by mono clinical ridges and valleys.
 Old folded mountains:
 Extremely affected by the denudational process.
 Eg: Aravalis, Vindhyanchal etc.
II. Block/ Fault-Block/ Horst mountains
○ Formation: By tensile and compressive forces by
endogenic factors.
○ Location: Between two faults or on either side of a
rift valley or a graben.
○ Eg: The Vosges mountains (in France) and the Black
Forest (in Germany) etc.
○ Characteristics:
 Formed when the earth's crust between two
fault lines is pushed to rise up (owing to
horizontal pressure from either side).
 Eg: Satpura range is a horst and the rivers
Narmada and Tapi flow along the rift valleys on
either side
 Generated when a portion of the earth's crust
collapses along two fault lines due to divergent
pressures.
 Eg: River Rhine (Germany) flows along a rift valley and the Black Forest and Vosges
represent the block mountains or horst on either side of it

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  Characterised by steep slopes and flattened summits.
 Moderate size and lack peaks.
○ Types:
 Tilted block mountains: one steep side represented by fault scarp and one gentle side.
 Lifted block mountains: Flattened summits of tabular shape and very steep side slopes
represented by two boundary fault scarps.
Origin: 2 theories
A. Fault Theory:
● opinion that block mountains are formed due to faulting.
● Formed in a number of ways:
○ Due to upward movement of the middle block between two normal faults.
○ When the side blocks of two faults move downward whereas the middle block remains stable at
its place
○ When the middle block between two normal faults moves downward.
B. Erosion theory:
● Opinion that these mountains were not formed due to faulting and tilting, rather they were formed due
to differential erosion.
● The mountains, after their origin in the Mesozoic era, were subjected to intense erosion.
● Consequently, differential erosion resulted in the formation of existing denuded Great Basin Range
mountains.
● Not acceptable to most of the scientists since they believe that denudation may modify mountains but
cannot form a mountain

III. Dome Mountains

○ Formation: By magmatic intrusions and upwarping of the crustal surface.
○ Location: In a region of flat-lying sedimentary rocks is warped or bowed upward making a
structural dome.
○ Eg: Normal domes, Lava domes, Batholithic domes, Laccolithic domes, Salt domes etc.
IV. Mountains Of Accumulation/ volcanic mountains:
○ Formation: Due to accumulation of volcanic materials.
○ Eg: cinder cones, composite cones, acid lava cones, basic lava cones etc
4. On the Basis of Period of Origin
I. Precambrian Mountains:
 belong to the Precambrian period,
 subjected to upheaval, denudation and metamorphosis. So, the remnants appear as Residual
Mountains.
 Ex: Laurentian mountains, Algoma mountains etc.
II. Caledonian Mountains:
 Belongs to late Silurian and early Devonian periods.
 Ex: The Appalachians, Aravalli and Mahadeo Hills etc.
III. Hercynian Mountains:
 Belongs to Upper Carboniferous to Permian period in Europe.
 Ex: mountains of Vosges and black forest, Altai, Tianshan Mountains of Asia, Ural Mountains etc.
IV. Alpine System:
 Belongs to the tertiary period
 Ex: Rockies of North America, Alpine mountains of Europe, Atlas Mountains of North-Western Africa,
Himalayas of the Indian subcontinent, etc.

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Major Mountains of the world:

Fig: location of fold mountains

Mountain Important/ Higest
S.No. Location Description
Range Peaks
1. Rocky Mt. Elbert (highest North America It is one of the longest fold mountains
Mountain peak in the Rockies) in the world and extends from Canada
to western US (New Mexico State)
2. Appalachain Mt. Aitchell, North North America It is fold mountain with rich in mineral
Mountains Carolina, US (higest resources.
peack of Appalachian
Mountains)
3. Alphs dMont Blanc (French – Europe It is a folded mountain and source for
Italian Border) river like Danube, Rhine etc.
4. Sierra Mt. Whitney California, USA Habitat for many Red Indian tribes
Nevada
5. Alaska Range Mt. McKinley North America Mt. McKinley highest peak in North
America
6. Altai Belukha mountain Central Asia Young folded mountain which extends
Mountains from Kazakhstan to northern China.
7. Andes Mt. Aconcagua South America Longest Mountain chain in the world
Mountains
8. Atlas Mt. Toubkal Northwestern Young fold mountain spreading over
Mountains Africa Morocco and Tunisia.
9. Drakensberg Mt. Lesotho South Africa Young folded mountain
Mountains

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 10. Caucasus Mt. Elbrus Europe Located between the Black sea and the
Mountain Caspian sea
11. Ural Mt. Narodnaya Russia This mountain range act as a boundary
Mountains between Europe and Asia.
12. Hindukush Mt. Trich Mir Pakistan and Folded mountain with rugged
Mountains Afganistan topography which makes it difficult for
transportation.
13. Himalyas Mt. Everest Asia Young fold mountains in Asia which
separates.
14. Arakhan Mt. Kennedy peak Myanmar It extends from north to south
Yoma direction. Shifting cultivation is
practiced.
15. Kunlun Mt. Muztag North of Tibetan It is one of the young folded mountains.
Mountains plateau and
western China
16. Vosges Mt. Grand Ballon Eastern, France, Famous for the cultivation of grapes
Europe and manufacture of wines

17. Great Mt. Kosciuszko Australia This range is the source for the rivers
Dividing Darling and Murray.
Range
Plateaus
● A raised area with terrain that is levelled on top.
● Features a big top surface area and a steep side slope.
● aka High plains or tablelands
● Cover ~ 18% of land
● Found on every continent and cover 1/3rd of the Earth's surface.
● Young or old- Deccan plateau - old
● Tibet Plateau- highest
● Have abundance of mineral resources.
● Formation:
○ Form over millions of years as fragments of the Earth's crust collide, melt, and gurgle back to the surface.
○ Some were created by a single process
○ Others- several processes over the course of Earth's history.

Major Process of Plateaus Formation:

● Volcanism: from eruptions that occurred during the Cenozoic or Mesozoic.
○ Eg: Deccan Plateau, Columbia Plateau(US),Laurentian plateau or The Canadian Shield and the Siberian
Traps of Russia.
● Crustal shortening : Thrusting of one block of crust over another and occurrence of folding.
○ Eg: Tibet Plateau, plateaus in North Africa, Turkey, Iran.
● Thermal expansion: Replacement of cold mantle lithosphere by hot asthenosphere.
○ Eg: Ethiopian Highlands (Africa), Yellowstone Plateau(US),Massif Central (France)

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Classification of Plateaus
1. Intermontane Plateaus
● Intermontane: Area between two mountains.
● Occurrence: Majorly bordered by mountain ranges (usually fold mountains) or are partially
or completely enclosed inside them.
● Highest Plateaus on the planet.
● Features: Almost horizontal rock layers that are uplifted to great heights by the earth's vertical
movements.
● Eg: Tibetan Plateau , Bolivian plateau etc.

Fig: intermontane plateau

2. Piedmont Plateaus
● Piedmont: Mountain foot.
● Occurrence: Foot of a mountain and are bordered by a plain on one side or a sea/ocean.
● aka Plateaus of denudation as places formerly high to the level of mountains but have now been reduced
to the mountain's foot level due to numerous agents of erosion.
● Examples: The Malwa Plateau (India), Patagonian plateau (Argentina) etc.

Fig: Piedmont plateau

3. Continental Plateaus
● aka Plateaus of Accumulation.
● Occurrence: Bordered on all sides by the plains or seas, forming away from mountains.
● Formation: Due to either a large-scale continental uplift or the spread of horizontal basic lava sheets (less
viscous) that entirely cover the old landscape.

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 ● Feature: In contrast to the neighbouring plain or sea, these plateaus have a sharp elevation (i.e. more
steepness on sides).
● Eg: The Maharashtra Plateau, Antarctic Plateau or Polar Plateau in East Antarctica

Fig: The Continental PLateaus

4. Volcanic Plateaus
● Formation: by volcanic activity.
● Types:
○ Lava plateaus: Generated by extremely fluid basaltic lava flowing through a series of vents without
causing violent explosions.
○ Pyroclastic plateaus: Formed by massive pyroclastic flows and are underlain by pyroclastic rocks.
● Eg: Antrim plateau (Ireland), The Deccan Plateau (India), The Columbia Plateau (US) etc.
Pyroclastic flow: A fast-moving river of hot gas and volcanic materials that flows out from a volcano at rates
of up to 700 km/h on average.

5. Dissected Plateaus
● Dissected : Area that has been severely eroded such that the relief is sharp.
● Formation: Due to upward movement in the Earth’s crust caused by the slow collision of tectonic plates.
● Feature: The region will appear to be mountainous.
● Examples:Ozark Plateau (US),Hornsby Plateau (Australia), The Deccan Plateau (India) etc.

Major Plateaus of the world

Fig: Distribution of Plateaus across the world.

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● Tibetan Plateau
○ Highest and largest plateau in the world
○ aka ‘roof of the world’.
○ Formed due to collision of the Indo-Australian and Eurasian tectonic plates.
○ Sufficiently high enough to reverse the Hadley cell convection cycles.
○ Covers- Autonomous Tibetan Region, Qinghai Province of Western China, and a part of Ladakh in Jammu
and Kashmir.
○ Surrounded by mountains to the south by the Himalayan Range, to the northeast by the Kunlun Range,
and to the west by the Karakoram Range.
● Columbia – Snake Plateau
○ River Columbia and tributary Snake meet in this plateau.
○ Bordered by the Cascade Range and Rocky Mountains and divided by the Columbia River.
○ Formed as the result of volcanic eruptions with a consequent coating of basalt lava (Flood Basalt
Plateau).
● Colorado Plateau
○ Western part of U.S.A.
○ Largest plateau in America.
○ Divided by the Colorado River and the Grand Canyon.
○ Example of intermontane plateau. Mesas and buttes are found here at many places [Arid Landforms].
○ Known for the groundwater which is under positive pressure and causes the emergence of springs called
Artesian wells.
● Deccan Plateau
○ Forms most of the southern part of India.
○ Bordered by two mountain ranges, the Western Ghats and the Eastern Ghats.
○ Includes the Deccan Traps - largest volcanic feature on Earth.
○ Made of multiple basalt layers or lava flows, the Deccan Traps covers 500,000 square kilometers in area.
○ Known for containing some unique fossils.
○ Rich in minerals- mica and iron ore in the Chotanagpur region, and diamonds, gold and other metals in
the Golconda region.
● Kimberley Plateau
○ Lies in the northern part of Australia.
○ Made of volcanic eruption.
○ Minerals- iron, gold, lead, zinc, silver and diamond are found here.
● Katanga Plateau
○ In Congo.
○ Famous for copper production.
○ Minerals - Cobalt, Uranium, Zinc, Silver, Gold and Tin.
● Mascarene Plateau
○ Plateaus also form in the ocean, such as the Mascarene Plateau in the Indian Ocean.
○ Extends between the Seychelles and Mauritius Islands.
● Laurentian Plateau
○ Lying in the eastern part of Canada, it is a part of Canadian Shield.
○ Fine quality of iron-ore is found here.
● Mexican Plateau
○ aka ‘Mineral Store’.
○ Metallic minerals - silver, copper etc..
○ World’s biggest silver mine Chihuahua is situated in the plateau.

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● Patagonian Plateau
○ Piedmont plateau (Arid Landforms) lying in southern part of Argentina.
○ Rain shadow desert plateau.
○ Important region for sheep rearing.
● Altiplano Plateau or Bolivian Plateau
○ Intermontane plateau which is located between two ranges of Andes Mountain.
○ Major area of Tin reserves.
● Massif Central
○ This plateau lies in central France.
○ Famous for Grapes cultivation.
● Anatolian Plateau
○ aka Asia Minor, most of Turkey lies on this plateau.
○ Intermontane plateau lying between Pontiac and Taurus Mountain ranges.
○ Tigris – Euphrates Rivers flow through this plateau.
○ Precious wool producing Angora goats are found here.
● Others
○ Spanish Plateau / Iberian Plateau: middle of Spain. It is a lava plateau. It is rich in minerals like Iron.
○ Loess Plateau: It is in China. The soil here is made of fine particles brought by the wind. This fine loamy
soil is extremely productive. Crops grown in this soil along the Yellow River give great yields.

Plains
● A low-lying, relatively flat land surface with a low local relief and a very mild slope.
● Most common landforms on the surface of the planet.
● Occurrence: On every continent.
● Area: > 55 % of the earth's land surface.
● Formation: By the deposition of sediments carried down by rivers.
● Factors in Formation: Aside from rivers, wind, shifting ice, and tectonic activity have all contributed to the
formation of plains.
● Examples: Indo Gangetic Plains, Mississippi Plains & Yang-Tze plain

Classification of Plains
● On the basis of their mode of formation:
A. Structural plains
o Undisturbed plain landforms on the Earth’s surface.
o Structurally depressed areas which make up some of the most expanse natural lowlands on
Earth.
o Formed from horizontally bedded rocks relatively undisturbed by crust movements of the Earth.
o Created by an uplifting diastrophic movement of a large landmass.
o Eg: Russian Platforms, Great plains (USA) & Central lowlands (Australia).
B. Erosional Plains (Peneplains)
o Plain landforms produced from action of various agents of denudation (River, running water, glacier
and wind) on an existing landform.
o Agents wear out the rugged surface on an existing landform and smoothens them - low undulating
plain landforms.
o Major types :
 Peneplains (Almost plain): Results from the action of the various agents of denudation mentioned
above, exempting wind.

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  Pediplains or Pediments: Mountain slopes are worn away by mechanical weathering in dry and
semi-arid locations, leaving a gentle slope.
 Desert Plains: Produced by wind Erosion. Eg: Reg, serir and hamada in sahara.
 Karst Plains: Massive limestone plateaux are vulnerable to chemical weathering and erosion by
groundwater, eventually transforming into a depressed topographic surface with low relief. Eg:
The Canadian shield and the West Siberian plain.
C. Depositional Plains
o Formation: Due to depositional action of numerous geomorphic processes.
 Riverine or alluvial plains: Plains formed by river deposits.
 Lacustrine Plains or Lake Plains: By sediment deposition in a lake. Eg: Kashmir Valley.
 Glacial or Drift Plains: Produced by glacial deposits.
 Loess Plains: when the wind is the primary deposition mechanism.
o Feature: Most productive agricultural plains of the world.
o Examples: Gangetic plain (for rice & jute), Nile delta of Egypt (for rice & cotton) & Hwang ho plain in
China
o Types:
1. Alluvial plains:
 Vast, sweeping stretches of plain land that are formed by the deposition of sediments called
alluvium.
 Represents the pattern of floodplain shift over geological time.
 River flows down mountains or hills- carries sediments resulting from erosion and transports
the sediments to the lower plain.
 Sediments build up over time- elevation of the floodplain increases and width of the river
channel decreases.
2. Flood plain
 Plain that stretches from the banks of a river or stream to the enclosing valley walls.
 Usually subjected to flooding when the adjacent water body overflows.
 Fertile and are made of deposits of silts, sands, levees, etc., deposited by floodwaters.
 Usually support a rich ecosystem.
 Most devastating floods in history have taken place here.
 Eg. Yellow River’s floodplains.
3. Scroll plain
 Formed where a river meanders across a low gradient.
 Deposition of sediments at such locations - Plains formed.
 Oxbow lakes are common occurrences in such areas.
 Eg. Taieri River
4. Lacustrine plain
 Formed in areas previously occupied by lakes.
 When a lake drains out completely, sediments remain behind on the lakebed to form a plain.
 Might be highly fertile and support agriculture or might form a wetland or even a desert
depending on the composition of the sediments.
 Common in Southern Indiana of the US .
 Eg. Kashmir Valley of India
5. Lava plain/ Lava field
 Formed by the accumulation of layers of lava.
 Can stretch for miles and are easily visible from the air or in satellite images - appear darker
in color than the surrounding landscape.

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 D. Glacial plains
o Formed by the movement of glaciers under the force of gravity.
o Categorized as:
 Outwash plains/ Sandur :
 Formed when a glacier deposits sediments at its terminus.
 As a glacier moves, it erodes the bedrock and carries the eroded sediments downstream.
 These sediments are deposited by the meltwater of the glacier at the snout.
 Common landform in Iceland.
 World's largest outwash plain- Skeiðarársandur in Iceland - 1,300 square km.
 Till plain
 Formed by the deposition of glacial till (unsorted glacial sediment).
 When a sheet of glacial ice gets detached from the main glacier and melts in place, the
sediments are deposited on the ground to result in the formation of a till plain.
 Can be seen in northern Ohio where they were created by the Wisconsin glaciation.
E. Abyssal plain
o Located at great depths - between 9,800 ft and 20,000 ft.
o Comprise- ~ 50% of the earth's surface of our planet.
o World’s least explored areas as well as the flattest and smoothest ones.
o Massive in size.
o Eg. Sohm Plain of the North Atlantic Ocean - 900,000 square km. Most common in the Atlantic
Ocean but quite rare in the Pacific Ocean.
o Considered to be formed by the deposition of sediments, derived from land, in the abyssal
depressions.
Major plains of the world
1. Indo-Gangetic plain of India
● Lies in the south of the Himalayas stretching from the Sulaiman mountains to the Gargo
and Lushai Hills.
● ~ 100 to 300 miles wide.
● Flat and alluvial plain with deep and fertile soil.
● One of the most thickly populated parts of the world.
2. Llanos (S.America)
● The vast plains of the Orinoco basin.
● Dry season - desert
● Rainy season - abundance of grass.
3. Lombardy Plains
● Most fertile parts of Italy watered by the River Po.
● Major activities- Corns, fruits and mulberry plants over which silkworm is reared.
4. Pampas (S. America)
● Wide, treeless, grass-covered plains of the La Plata river system.
● Most extensive pasture lands in the world.
5. Selvas
● Vast impenetrable forests of the Amazon Valley.
● Region of great heat and heavy rainfall.
● Has the largest forest in the world?
6. Steppes
● Vast treeless plains of Russia extending from the Caspian Sea eastwards.
● Very hot in summer and very cold in winter and have no rainfall.

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7. Tundras
● Swampy plains near the Poles in the extreme north of America, Asia and Europe.
● Remain frozen for about nine months.
● Major activities- Fishing and hunting.

Other important plains- Veldt in South Africa, Downs in Australia, Prairies in North America, Savannah in
Northern Africa and Parklands in East Africa.

Deserts
Types of Deserts
Subtropical Deserts
 Subtropical deserts are caused by the circulation patterns of air masses.
 They are found along the Tropic of Cancer, between 15 and 30 degrees north of the Equator, or along the
Tropic of Capricorn, between 15 and 30 degrees south of the Equator.
 Hot, moist air rises into the atmosphere near the Equator. As the air rises, it cools and drops its moisture as
heavy tropical rains. The resulting cooler, drier air mass moves away from the Equator. As it approaches the
tropics, the air descends and warms up again. The descending air hinders the formation of clouds, so very little
rain falls on the land below.
 For example: Sahara Desert (Africa), Kalahari Desert (Africa) and the Tanami Desert (Australia)

Coastal Deserts
 Cold ocean currents contribute to the formation of coastal deserts.
 Air blowing toward shore, chilled by contact with cold water, produces a layer of fog.
 This heavy fog drifts onto land.
 Although humidity is high, the atmospheric changes that normally cause rainfall are not present.
 A coastal desert may be almost totally rainless, yet damp with fog.
o For example: the Atacama Desert, on the Pacific shores of Chile, is a coastal desert. It is the Atacama
Desert is the driest place on Earth.

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Rain Shadow Deserts
 Rain shadow deserts exist near the leeward slopes of
some mountain ranges.
 Leeward slopes face away from prevailing winds.
 When moisture-laden air hits a mountain range, it is
forced to rise.
 The air then cools and forms clouds that drop moisture
on the windward (wind-facing) slopes.
 When the air moves over the mountaintop and begins
to descend the leeward slopes, there is little moisture
left.
 The descending air warms up, making it difficult for
clouds to form.
o For example: Death Valley, in the U.S. states of California and Nevada, is a rain shadow desert.
o Death Valley, the lowest and driest place in North America, is in the rain shadow of the Sierra Nevada
mountains.
Interior Deserts
 Interior deserts, which are found in the heart of continents, exist because no moisture-laden winds reach
them.
 By the time air masses from coastal areas reach the interior, they have lost all their moisture.
 Interior deserts are sometimes called inland deserts.
o For example: the Gobi Desert, in China and Mongolia

Polar Deserts
 Parts of the Arctic and the Antarctic are classified as deserts.
 These polar deserts contain great quantities of water, but most of it is locked in glaciers and ice sheets year-
round.
o So, despite the presence of millions of liters of water, there is actually little available for plants and
animals.
 The largest desert in the world is also the coldest.
 Almost the entire continent of Antarctica is a polar desert, experiencing little precipitation.
 Few organisms can withstand the freezing, dry climate of Antarctica.
Important Deserts of the World

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 Important
Type of desert Location
Deserts
Polar ice and
Antarctica Antarctica
tundra
Northern America (Alaska, Canada and Greenland)
Polar ice and Northern Europe (Finland, Iceland, Norway and Sweden)
Arctic
tundra Eastern Europe (European Russia)
North Asia (Siberia)
North Africa (Algeria, Egypt, Libya, Morocco, Sudan and Tunisia)
West Africa (Mali, Mauritania and Niger)
Sahara Subtropical
Middle Africa (Chad)
East Africa (Eritrea)
Australian
Subtropical Australia
Desert
Western Asia (Iraq, Jordan, Kuwait, Oman, Qatar, Saudi Arabia, United
Arabian Desert Subtropical
Arab Emirates and Yemen)
Gobi Desert Cold East Asia (China and Mongolia)
Southern Africa (Botswana, Namibia and South Africa)
Kalahari Desert Subtropical
Middle Africa (Angola)
Patagonian
Cold South America (Argentina and Chile)
Desert
Syrian Desert Subtropical Western Asia (Iraq, Jordan, and Syria)
Great Basin Cold United States
Chihuahuan Central America (Mexico)
Subtropical
Desert Northern America (United States)
Karakum Desert Cold Turkmenistan
Colorado
Cold United States
Plateau
Central America (Mexico)
Sonoran Desert Subtropical
Northern America (United States)
Kyzylkum Desert Cold Central Asia (Kazakhstan, Turkmenistan and Uzbekistan)
Taklamakan
Cold China
Desert
Thar Desert Subtropical Indian Subcontinent (India and Pakistan)
Dasht-e Margo Subtropical Afghanistan
Registan Desert Subtropical Afghanistan
Atacama Desert Mild Coastal South America (Chile and Peru)
Mojave Desert Subtropical United States
Columbia Basin Cold United States
Southern Africa (Namibia)
Namib Desert Cool Coastal
Middle Africa (Angola)
Dasht-e Kavir Subtropical Iran
Dasht-e Loot Subtropical Iran

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Rivers
Types of Drainage patterns
Concordant drainage patterns

● Concordant if drainage pattern correlates to topology and geology of area.

● Path of river is highly dependent on slope of river and topography.
● Most commonly found drainage patterns.
● Classified into:
○ Consequent Rivers:
■ Follow general direction of the slope.
■ Most of peninsular rivers.
■ Eg, Godavari, Krishna andCauvery, descending from the Western Ghats and flowing into the Bay of
Bengal.
○ Subsequent Rivers:
■ A tributary stream formed by headward erosion along an underlying rock after the main drainage
pattern has been established.
■ Eg. Chambal, Sind, Ken, Betwa, Tons andSon meet Yamuna andGanga at right angles.
● So, subsequent drainage of the Ganga drainage system.
○ Obsequent Rivers:
■ May form at right angles to the subsequent rivers and flow opposite to the direction of flow of the
original consequent river after the valley development of consequent and subsequent rivers.
○ Resequent Rivers
■ Flows in same direction of initial consequent drainage.
■ Originate at a much later stage wrt master consequent rivers.
Discordant or Insequent drainage patterns
● Discordant if it does not correlate to topology and geology of the area.
● River follows its initial path irrespective of the changes in topography.
● Classified into antecedent and superimposed.
● Rivers in both drainage types flow through a highly sloping surface.
○ Antecedent Drainage or Inconsequent Drainage:

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