Exam Notes
Asia: Location, Political and Physical Features
Asia is the largest continent, occupying about one-third of the world's total land area, approximately 30% of Earth's total land area. It plays a crucial role in global climate patterns, biodiversity, and resource distribution.
It lies mostly in the northern and eastern hemispheres, often referred to with Europe as Eurasia, a vast landmass sharing cultural and historical contexts. The exact boundary between Europe and Asia is a topic of ongoing discussion, often based on cultural, historical, and geographical factors.
It stretches between latitudes 10°S-80°N and longitudes 25°E-170°W, covering approximately 45.03 million sq. km. This extensive range contributes to a wide array of climates, landscapes, and ecosystems, from tropical rainforests to arctic tundra.
Asia has the largest population, estimated at 4.7 billion in mid-2021, about 60% of the world's total. This population is distributed unevenly, with high concentrations in East, South, and Southeast Asia and sparse populations in Central and North Asia.
It is separated from Europe by the Ural Mountains, the Caspian Sea in the west, and the Caucasus Mountains in the southwest. These geographical features form a conventional boundary, but the cultural and historical interactions blur the distinction between the two continents.
The Arctic Ocean lies to the north, the Pacific Ocean to the east, and the Indian Ocean to the south. These oceans significantly influence Asia’s climate, weather patterns, and maritime activities.
East-west extent is 9,700 km, with an 11-hour time difference between the Anatolian Plateau and the Pacific Coast. This vast longitudinal span results in diverse time zones and varied daily life experiences.
There are 48 independent countries in Asia, varying in size from Russia, China, and India to Singapore, the Maldives, and Bahrain. These countries exhibit a wide range of political systems, economic development levels, and cultural identities.
Some countries, like Japan, the Philippines, and Indonesia, consist of island groups or archipelagoes. These island nations have unique cultural and geographical characteristics shaped by their maritime environment.
Many Asian countries gained independence after World War II and the partition of the Indian peninsula in 1947. These historical events led to significant political and social transformations, shaping modern Asia.
In 1991, the USSR broke up into several independent republics, some now in Europe and some in Asia. This dissolution altered the geopolitical landscape, creating new nations and redefining regional dynamics.
Asia at a Glance:
Latitudinal extent: 10°S-80°N
Longitudinal extent: 25°E-170°W
Widest distance: 8,690 km (North-South), 9,700 km (East-West)
Length of coastline: 129,077 km
Number of countries: 48
Largest country: Russia
Smallest country: The Maldives
Most industrialized country: Japan
Highest elevation: Mt. Everest (8848.86 m)
Highest plateau: Plateau of Tibet
Lowest point: Dead Sea (400 m below sea level)
Deepest sea: South China Sea
Deepest lake: Lake Baikal
Longest strait: Strait of Malacca
Coldest place: Verkhoyansk, Russia (-70°C)
Warmest place: Dasht-e-Lut, Iran (70.7°C surface temperature in 2021)
Regional Divisions of Asia:
Asian countries are grouped based on their locations:
East Asia: Includes China, North and South Korea, Japan, and Mongolia; varied vegetation, busy cities like Tokyo, Beijing, Shanghai, and Hong Kong; population around 1.6 billion. China, with over 1.4 billion people, is the world's most populous country and a major economic power. Japan is known for its technological advancements and cultural heritage.
North Asia: Comprises the Asian part of Russia, including Siberia and the Russian Far East; divided by the Ural Mountains; long, severe winters; sparsely populated (about 38 million). Siberia is rich in natural resources, including oil, gas, and minerals, but its harsh climate poses challenges for development.
Central Asia: Landlocked countries, including Kazakhstan, Uzbekistan, Kyrgyzstan, Tajikistan, Turkmenistan, and Afghanistan; extends from the Caspian Sea to western China; 60% deserts, 40% grasslands; Altai Mountains in the east; Amu Darya and Syr Darya rivers; population about 67.3 million. These countries have strategic importance due to their location and natural resources, but they also face issues related to political stability and economic development.
South-East Asia: Northern mainland part includes Vietnam, Laos, Cambodia, Thailand, and Myanmar; southern island part includes Malaysia, Singapore, Brunei, Indonesia, East Timor, and the Philippines; tropical rainforests and wildlife; population about 1,823 million. This region is known for its diverse cultures, vibrant economies, and strategic location along major trade routes.
South Asia: Includes India, Pakistan, Nepal, Sri Lanka, Bhutan, Maldives, and Bangladesh; bounded by the Himalayan Mountains, the Bay of Bengal, the Arabian Sea, and the Indian Ocean; densely populated (around 1.8 billion); diverse natural vegetation and wildlife. India is the largest country in this region and a rising global power, while the others have unique cultural and geographical characteristics.
West Asia: Includes Armenia, UAE, Yemen, Azerbaijan, Bahrain, Lebanon, Oman, Cyprus, Syria, Turkiye, Georgia, Iran, Israel, Jordan, Kuwait, Qatar, and Saudi Arabia; population about 257.23 million; not densely populated; inhospitable climate. This region is strategically important due to its oil reserves and geopolitical dynamics.
Physical Features of Asia
Asia is divided into five physical regions:
The Northern Lowlands
The Central Fold Mountains and Inter-montane Plateaux
The Southern Plateaux
The Great River Valleys
The Island Chains
The Northern Lowlands
Extends from the Ural Mountains to the Bering Strait.
Triangular shape, widest in the west.
Lies between the Arctic Ocean and the Central Mountains.
Known as the Great Siberian Plain, marshy and swampy. The West Siberian Plain is one of the world's largest regions of continuous flatland.
Formed by rivers Ob, Yenisey, and Lena flowing into the Arctic Ocean. These rivers play a vital role in the region's hydrology and ecology.
Includes the Turan Plain, drained by the Amu Darya and Syr Darya rivers. The Aral Sea, once a major feature of this plain, has significantly reduced in size due to water diversion projects.
The Central Fold Mountains and Inter-montane Plateaux
Complex system of fold mountain ranges and plateaus south of the Northern Lowlands.
Mountain ranges meet at the Pamir Knot. The Pamir Knot is a complex orographic feature where several major mountain ranges converge.
Major ranges radiate outwards, including the Kunlun and Tien Shan mountains to the east and north.
The Himalayas extend southeast as a wide arc across northern India, turning south into Myanmar as the Arakan Yoma Range. The Himalayas are the highest mountain range in the world, containing many of the world's tallest peaks.
The Karakoram Range extends southeast from the Pamir Knot, between the Kunlun and Himalayas. K2, the second-highest peak in the world, is located in this range.
The Plateau of Tibet is an inter-montane plateau between the Kunlun and Himalayas, also called the 'roof of the world' with an average height of 4,880 m above sea level. The Plateau of Tibet has a significant impact on Asia's climate and hydrology, influencing monsoon patterns and river systems.
Hindu Kush Range continues westward as the Elburz Mountains.
Sulaiman Range radiates southwest from the Pamirs, continuing as the Kirthar and Zagros ranges.
These mountains enclose the Plateau of Iran, converging at the Armenian Knot.
The Pontic and Taurus ranges radiate westward from the Armenian Knot, enclosing the Plateau of Anatolia.
The Altai, Yablonovy, and Stanovoy mountain ranges extend northeast beyond the Tien Shan.
The Khingan mountains extend north-south, parallel to the coast north of the Huang He Basin.
The Southern Plateaux
Includes the Arabian Plateau, the Deccan Plateau, and the Shan and Yunnan Plateaux.
Regions of old, hard crystalline rocks at some height above sea level, with undulating and gently sloping surfaces.
The Arabian Plateau is steeper in the west, sloping eastward towards the Persian Gulf; dry with no rivers. The Arabian Plateau is predominantly desert, with limited freshwater resources.
The Deccan Plateau of India lies between the Western Ghats and the Eastern Ghats; steeper in the west, sloping towards the Bay of Bengal; crossed by rivers. The Deccan Plateau is rich in minerals and has a diverse range of ecosystems.
shan Plateau in Myanmar and the Yunnan Plateau in China are drained by the Salween, Mekong, and Si Kiang rivers. These rivers are vital for agriculture and transportation in Southeast Asia.
The Great River Valleys
Large rivers rise in the mountains and plateaus, snow-fed and perennial.
Fertile and densely populated valleys.
Larger river valleys built by the Tigris, Euphrates, Indus, Ganga, Brahmaputra, Chao Phraya or Menam, Chang Jiang or Yangtze, Huang He and Si Kiang rivers.
Small plains formed along Irrawaddy, Salween, Mekong and Amur rivers.
The Mesopotamian plains in Iraq consist of the land between the Tigris and Euphrates rivers. This region is considered the cradle of civilization and has a rich history.
The Indus River and its five tributaries built the fertile plains of Pakistan and Punjab in India. The Indus Valley Civilization, one of the world's oldest urban civilizations, thrived in this region.
The Ganga-Brahmaputra Plains are spread across north India and Bangladesh. This is one of the most densely populated regions in the world and is highly productive for agriculture.
The three big rivers Huang He, Chang Jiang, and Si Kiang build the large plains in China. These rivers are essential for China's agricultural production and economic development.
The Manchurian Plain is formed by river Amur and the plains of Indo-China are formed by the rivers Mekong and Menam.
River Irrawaddy forms a large plain in Myanmar.
The Island Chains
Series of island chains lies to the east and southeast of mainland Asia.
From the tip of the Kamchatka Peninsula, the Kuril Islands, the Japanese Islands, the Ryukyu Islands, the Philippines, and the Indonesian Islands.
The Andaman and Nicobar Islands, Sri Lanka, the Maldives, and the Lakshadweep Islands are in South Asia.
Asia Climate and Natural Vegetation
Factors Affecting Climate
The climate of Asia varies greatly from north to south and east to west, affecting vegetation and wildlife. Asian climates range from Arctic conditions in Siberia to tropical conditions in Southeast Asia, resulting in a wide array of biomes and species.
Variations occur from place to place and season to season. These variations influence agricultural practices, water resource management, and human settlement patterns.
Factors affecting climate:
Longitudinal and Latitudinal extent: Asia is the largest continent, stretching across the torrid, temperate, and frigid zones. This extensive spread leads to diverse climate zones, including equatorial, monsoon, desert, temperate, and arctic climates.
Distance from the Sea: Interior parts experience extreme conditions and continental climate; coastal areas have equable or maritime climate. Coastal regions benefit from the moderating influence of the ocean, resulting in milder temperatures and higher humidity, while inland areas experience greater temperature fluctuations.
Relief Features: Mountain ranges in an east-west direction form barriers to moisture-bearing winds and cold winds. The Himalayas, for example, block cold air from Central Asia, leading to warmer temperatures in South Asia.
Mountains create rain shadows, leading to variations in precipitation and temperature. The windward slopes of mountains receive heavy rainfall, while the leeward side remains dry, creating arid conditions.
Plateaus and plains have distinct climatic characteristics (e.g., cold Tibetan Plateau). The Tibetan Plateau, with its high elevation, experiences extremely cold temperatures and low oxygen levels.
Coastal regions benefit from moderating effects of nearby bodies of water. The proximity to oceans or large lakes moderates temperature extremes and increases humidity.
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Monsoon Wind: Critical climatic factor in South and Southeast Asia; seasonal wind patterns influenced by temperature contrasts bring heavy rainfall in the wet season and dry conditions in the dry season. The monsoon is vital for agriculture and water resources in these regions but can also cause devastating floods.
Ocean Currents: The cold Oya Siwo and the warm Kuro Siwo affect the temperatures of coastal regions of Japan. These currents influence sea temperatures, marine ecosystems, and weather patterns.
Mixing of these currents provides suitable temperatures for fish breeding. This mixing supports rich marine biodiversity and productive fisheries.
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Quick Facts
Asia has very hot and very cold places and the wettest and driest places in the world. This climate diversity supports a wide range of ecosystems and species.
Mawsynram in India: annual rainfall of about 1,187 cm.
Arabian and Gobi Deserts and Tibet: rainfall less than 25 cm.
Summer Conditions
From April to June, the sun's rays fall directly over the northern hemisphere.
Most of Asia is warm, with an average temperature of about 32°C, except the extreme northern parts.
The world's highest surface temperature (71°C) has been recorded in Dasht-e Lut in Iran.
Hot air rises, creating a low-pressure area, leading to the movement of warm, moisture-laden onshore winds (monsoons).
Monsoons cause heavy rainfall in southern Asia and some parts of Japan.
Winter Conditions
From October to March, Asia experiences winter.
Temperatures fall to 0°C and below in many parts of northern Asia.
Verkhoyansk in Russia: average temperature of -51°C in January.
Cold, heavy air causes high pressure, leading to movement of cold air from land to sea.
Most of Asia receives no winter rainfall, except southeast Asia, Japan, south-eastern India, and parts of northern Sri Lanka.
South-west Asia receives winter rainfall from temperate cyclones originating over the Mediterranean Sea.
Types of Climate
Equatorial Climate: Near the equator; high temperatures (28-30°C) and rainfall all year round; very low annual range of temperature; convectional rainfall almost daily; dense hardwood forests with broadleaved tree species (mahogany, ebony, rosewood, cinchona, coconut, rubber); lianas, creepers, climbers, tall grass, ferns, and bamboo; arboreal animals, reptiles, insects; large animals only in the outskirts.
Tropical Monsoon Climate: Distinct seasons - hot wet summers and cool dry winters; summer rainfall caused by monsoon winds; heavier rainfall in coastal regions and windward slopes; experienced in India, Pakistan, Bangladesh, Myanmar, Thailand, Vietnam, Laos, Cambodia, and southern China; tropical deciduous forests (monsoon forests) with hardwood, broad-leaved trees (teak, sal, shisham, mango); grasses and thorny bushes in drier regions; elephants, rhinoceros, bears, deer, apes, lions, tigers, leopards.
Tropical or Hot Desert Climate: Prevails in Arabia, Iran, and the Thar Desert; very hot dry summers and very cold winters; high daily and annual ranges of temperature; less than 25 cm of rainfall annually; scarce vegetation; thorny bushes, shrubs, cacti, clumps of dry grasses; date palms in the oases; camels, horses, mules, gazelles, insects, and lizards.
Warm Temperate Eastern Margin or China-type Climate: Similar to the monsoon type, but winters are colder; snowfall in winter, rainfall in summer; experienced along the east coast of Asia in the warm temperate latitudes; mixed forests with evergreen and deciduous trees (oak, camellia, magnolia, chestnut, camphor, beech, fir); bamboo and mulberry shrubs; monkeys, foxes, birds.
Temperate or Mid-latitude Desert Climate: Found in the interior of the continent and on high plateaux (Gobi Desert and Plateau of Tibet); very little rainfall; very cold winters with temperatures below freezing point; hot summers; barren region with scattered tufts of coarse, short grasses and stunted, thorny bushes; lizards, insects, rodents, yak.
Mediterranean Climate: Characterized by warm, dry summers and cool, wet winters; found in west Asia (Syria, Turkey, Lebanon, and Israel); natural vegetation adapted to drought-like conditions; long roots and spongy barks; evergreen vegetation (laurel and acacia), oak, chestnut, walnut, olive trees; grain farms or orchards; domesticated animals.
Temperate Grassland or Steppe Climate: Occurs around the Caspian Sea region of Russia and in eastern Mongolia; extreme climatic conditions; hot and dry summers, cold and dry winters; little rainfall (25 to 75 cm annually); short grasses and low bushes; converted into farmlands or used for livestock rearing; antelope, horses, mules, wolves, Bactrian camel.
Cool Temperate Eastern Margin Climate: Experienced in eastern coastal regions, including eastern Siberia, North China, Manchuria, parts of Korea, and northern Japan; cold, very dry winters, and very warm, exceptionally wet summers; Heavy rainfall, warm summers, damp air and fog favor the growth of trees.
Cold Temperate Climate: evergreen softwood trees (pine, fir, spruce, larch, cedar); coniferous trees; sable, fox, bear, mink, lynx, squirrel.
India Location, Extent, Political and Physical Features
Location and Extent
India lies entirely in the northern and eastern hemispheres. Its mainland extends from 8°4'N to 37°6'N latitudes and 68°7'E to 97°25'E longitudes. The southernmost point is the Indira Point.
The Tropic of Cancer passes through India, dividing it into two parts. It influences the thermal environment of India, with the northern part experiencing a wider range of temperatures.
The 82½°E longitude is the Standard Meridian for India. Local time is uniform across the country, reducing the inconvenience of time differences.
Approximate area: 3.3 million sq. km. It is the seventh-largest country in the world by land area.
Neighboring countries: Pakistan, Afghanistan, China, Nepal, Myanmar, Bangladesh, Bhutan, and Sri Lanka. India shares land borders with these countries, influencing India’s foreign policy, trade, and cultural exchange.
Sri Lanka is separated from India by the Palk Strait and the Gulf of Mannar. These water bodies have historical and strategic importance, governing maritime boundaries and navigation.
The Maldives is located close to the Lakshadweep Islands. This proximity strengthens maritime cooperation and cultural ties.
India at a Glance
Latitudinal extent: 8°4'N-37°6'N
Longitudinal extent: 68°7'E-97°25'E
Area: 32,87,263 sq. km
North-south extent: 3,214 km
East-west distance: 2,933 km
Length of land frontier: 15,200 km
Length of coastline: 7,516.6 km
Number of states: 28
Number of union territories: 8
Capital: New Delhi
Political Divisions of India
India is divided into 28 states and 8 centrally administered union territories. States have their own elected governments, while union territories are administered by the central government.
The states were reorganized after Independence on the basis of language. Linguistic reorganization aimed to create administrative units aligned with cultural and linguistic regions.
Physiographic Divisions of India
India can be divided into six main physical divisions:
The Northern Mountains
The Great Northern Plains
The Peninsular Plateau
The Coastal Plains
The Thar Desert
The Islands
The Northern Mountains
Consist of the Himalayas and the hills of northeast India.
The Himalayas extend from Nanga Parbat to Namcha Barwa, covering a distance of over 2,400 km. The Himalayas are a young fold mountain range formed by the collision of the Indo-Australian and Eurasian plates.
The width varies between 15 and 400 km. The varying width influences the climate, vegetation, and accessibility of different Himalayan regions.
The three main ranges are:
The Greater Himalayas (Himadri)
The Lesser Himalayas (Himachal)
The Outer Himalayas (Shiwalik)
There are passes such as Shipki La, Thaga La, Nathu La, and Jelep La. These passes facilitate trade, migration, and strategic movement across the Himalayas.
Hills of the northeast are the Purvanchal ranges. These are an extension of the Himalayan range, characterized by dense forests and diverse ethnic groups.
The Great Northern Plains
Lie between the Northern Mountains and the Peninsular Plateau.
Extend from Punjab to the Brahmaputra Valley for a length of about 2,400 km. This plain is one of the most fertile and densely populated regions in the world.
Formed by sediments deposited by the Indus, the Ganga, and the Brahmaputra rivers. The alluvial soil is rich in nutrients, making it ideal for agriculture.
The alluvial soil is very fertile.
Divided into the Ganga Plains, the Punjab Plains, and the Brahmaputra Valley.
The Peninsular Plateau
An ancient land mass of hard crystalline rocks. It is one of the oldest and most stable landforms in India.
Triangular in shape.
Extends from the Aravalli Range to the Chota Nagpur Plateau. The Aravalli Range is one of the oldest fold mountain ranges in the world.
Divided by the river Narmada into the Malwa Plateau and the Deccan Plateau. The Narmada River flows in a rift valley, distinguishing the geological structure of the region.
The Coastal Plains
On either side of the Peninsular Plateau, with the Arabian Sea to the west and the Bay of Bengal to the east.
Divided into the Western Coastal Plains and the Eastern Coastal Plains. The Western Coastal Plains are narrower and more rugged than the Eastern Coastal Plains.
The Thar Desert
Vast, sandy low-lying plain with sandy ridges and shifting sand dunes. It is also known as the Great Indian Desert.
Lies mainly between the Aravallis in the east and the Sind Desert of Pakistan in the west.
Receives very little rain, less than 25 cm annually. It is one of the most densely populated deserts in the world.
The Island Groups
Two groups of islands:
The Andaman and Nicobar Islands in the Bay of Bengal. These are volcanic islands, characterized by dense tropical forests.
The Lakshadweep Islands in the Arabian Sea. These are coral islands, known for their beautiful beaches and marine biodiversity.
Drainage
The rivers of India are divided into the north Indian rivers (Himalayan rivers) and the south Indian rivers (peninsular rivers).
The North Indian Rivers (Himalayan Rivers)
The three important rivers are the Ganga, the Indus, and the Brahmaputra. These rivers are snow-fed and perennial, playing a crucial role in irrigation and water supply.
The South Indian Rivers (Peninsular Rivers)
The leading rivers of south India are the Mahanadi, the Godavari, the Krishna, the Kaveri, the Narmada and the Tapi. Most of these rivers are rain-fed and seasonal.
India-Climate, Flora and Fauna
Climate
India has a great variety of physical features and a tropical monsoon climate.
The Tropic of Cancer divides India into two nearly equal parts. This division influences the distribution of temperature and rainfall across the country.
Factors affecting the climate of India:
Latitude
Height above sea level
Northern mountains
Distance from the sea
Seasons
The climate of India is characterized by the following four main seasons:
The Hot Dry Season or the Summer season-March to May
The Hot Wet Season or the Rainy season-June to October
The Retreating Monsoons-October to November.
The Cool Dry Season or the Winter season-November/December to February
Rainfall
Rainfall in India is related to the winds and the relief features of the land. The monsoon winds bring most of the rainfall to India.
Importance of Monsoon
India has a tropical monsoon climate.
Monsoons bring rain to the whole of India. Agriculture and water resources in India are heavily dependent on the monsoon.
Vegetation
There is a great variety of vegetation and forest types in India. The diverse climate and relief features support a wide range of vegetation.
Vegetation in India can be divided into the following types:
Based on variation of rainfall:
Tropical evergreen forests
Tropical deciduous forests
Desert forests/Thorn forest/scrub
Based on variation of relief:
Tidal forests
Mountain forests
Wildlife
A great variety of animals are found in different parts of the country. India is one of the most biodiverse countries in the world.
The tiger is the national animal of India. It symbolizes India’s rich wildlife and conservation efforts.
The Asiatic lion is found in the Gir forests of Gujarat. Gir Forest is the only