VisionIAS - Video Classroom Lecture

Geography Class 01

Introduction (5:07 PM)

Topics to be covered

Earth’s twin movements- rotation and revolution
Effects of rotation
Effects of revolution
Earth’s tilt
Latitudes and Longitudes
Importance and usage of latitudes and longitudes
International Date Line (IDL)
Time zones
Indian Standard Time (IST)
Daylight saving time

Rotation

Earth spins around an imaginary line called its axis.
This spin or "rotation" happens roughly every 24 hours.

Effects of Rotation:

Apparent Movement of Celestial Bodies: The Sun appears to rise in the east and set in the west due to Earth's rotation.
Day and Night: As Earth rotates, different parts of the planet receive sunlight, resulting in daylight.
Simultaneously, the areas facing away from the Sun experience darkness or nighttime.
The "circle of illumination" is a term used in astronomy and geography to describe the dividing line between the daylit side and the night side of a celestial body, such as a planet or moon

Revolution

Revolution refers to the Earth's elliptical (oval-shaped) orbit around the Sun.
Duration: Earth completes its orbit around the Sun in about 365.25 days, which we round off to 365 days (1 year) for convenience.
The extra 0.25 days accumulate, and every fourth year, we add an extra day to our calendar, known as a leap year.

The Earth's Tilt and its Significance

Earth's axis is not upright; it is tilted from the perpendicular to the plane of its orbit at an angle of about 5°.

Effects of Revolution & Earth’s Tilt:

Changing Seasons: As Earth orbits the Sun, the tilt of its axis means different parts of the planet receive varying amounts of sunlight throughout the year. This variation in sunlight causes our seasons.
Varying Lengths of Day and Night: During its revolution, the Earth's tilt also leads to longer days in some seasons and shorter days in others, depending on one's location
Solstices: Days when the Sun's rays are directly overhead at the Tropics of Cancer or Capricorn, resulting in the longest and shortest days of the year
Summer Solstice (June 21st): Sun's rays directly overhead at the Tropic of Cancer, the longest day of the year in the Northern Hemisphere.
Winter Solstice (December 22nd): Sun's rays directly overhead at the Tropic of Capricorn, the shortest day of the year in the Northern Hemisphere.
Equinoxes: Days when the Sun's rays are directly overhead at the Equator, leading to equal lengths of day and night.
Vernal Equinox (March 21st): Sun's rays directly overhead at the Equator, leading to equal day and night lengths (spring equinox in the Northern Hemisphere).
Autumnal Equinox (September 23rd): Sun's rays directly overhead at the Equator, leading to equal day and night lengths (fall equinox in the Northern Hemisphere).

Latitudes and Longitudes

Geographical coordinates are a system used to pinpoint any location on Earth's surface using two numerical values – latitude and longitude.
Latitude: These are imaginary horizontal lines that circle the Earth and measure the distance north or south of the Equator (0°).
The North Pole is 90° N and the South Pole is 90° S.
Tropics: Two significant latitudes are the Tropic of Cancer (23.5° N) and the Tropic of Capricorn (23.5° S). These indicate the farthest points where the Sun can be directly overhead.
Arctic & Antarctic Circles: At 66.5° N and 66.5° S respectively, they mark the limits of the polar day and night.
Longitude: These are imaginary vertical lines that run from the North Pole to the South Pole.
They measure the distance east or west of the Prime Meridian (0°) which runs through Greenwich, London.
The Equator and Prime Meridian: While the Equator is the largest latitude circle, the Prime Meridian in Greenwich, England, serves as the zero-reference line for longitudes.
Great circle: A great circle is the largest circle that can be drawn on the surface of a sphere.
In terms of the "number of longitudes":
There are 360 degrees of longitude in total, going all the way around the Earth.
East of the Prime Meridian, longitudes are measured from 0° to 180° East.
West of the Prime Meridian, longitudes are measured from 0° to 180° West.
The Arctic Circle marks the southernmost latitude at which, on the winter solstice, the Sun will not rise all day, and on the summer solstice, the Sun will not set.

Importance and Usage of Latitudes and Longitudes

Mapping & Navigation: For centuries, sailors and explorers have utilized latitudes and longitudes for precise navigation on seas.
Climate & Agriculture: Latitude influences the amount of sunlight a region receives, affecting its climate.
Understanding latitude helps in predicting weather and determining suitable crops.
Study of Earth: Longitude and latitude grids assist researchers in understanding geological events like earthquakes by identifying their epicenters.
Standard Time Determination: Local time is based on the meridians.
Every 15° of longitude equals a time difference of one hour

Time Zones:

A time zone is an area that observes a uniform standard time for legal, commercial, and social purposes.
Time zones tend to follow the boundaries between countries and their subdivisions instead of strictly following longitude.
The Earth is divided into 24 time zones, each one covering 15° of longitude.
This system was adopted to ensure that when it's noon in a particular zone, the Sun is at its highest point in that zone's sky.
France- 12, Russia, USA-11
Greenwich Mean Time (GMT): The Prime Meridian time in Greenwich, London, was considered the standard reference time.
When the sun is at its highest point exactly above Greenwich, it is 12 noon GMT.
Coordinated Universal Time (UTC): GMT is based on astronomical observations while coordinated universal time (UTC) is based on atomic clocks. (Caesium 133)
A leap second is a second added to Coordinated Universal Time (UTC) in order to keep it synchronized with astronomical time.
The practice of adding leap seconds to clocks started in 1972. (Plan to abandon it from 2035)
Indian Standard Time (IST): Indian Standard Time (IST) is the time observed throughout India and Sri Lanka.
IST is 5 hours and 30 minutes ahead of Coordinated Universal Time (UTC+5:30).
The IST time zone is based on the Allahabad Observatory, near the city of Allahabad in the state of Uttar Pradesh, India.
The reference longitude for IST is 5°E.
In India, the Tropic of Cancer passes through 8 states-
Rajasthan, Gujarat, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal, Tripura and Mizoram.
The Indian Standard Meridian passes through 5 states-
Uttar Pradesh (UP)
Madhya Pradesh (MP)
Chhattisgarh
Odisha
Andhra Pradesh

Daylight saving time (DST)

It is a process of advancing clocks to extend daylight time in warmer months.
Because of this, the darkness appears at a later clock time.
The significance of DST is numerous such as - energy conservation, reduction in electricity costs, and thus reduction in greenhouse gas emissions leading towards achieving SDGs.
However, there are concerns about its impact on sleep patterns, health, and daily routines, thus it depends upon individual country’s preferences.

Map and Spatial Understanding (6:00 PM)

Table of Contents

Map and its types
Distinction between a Map and a Globe
Maps - What to focus on?
Plains, Plateaus, and Mountains
Strait and Isthmus
Human Environment: Settlement, Transport and Communication
Settlements; Classification; Rural and Urban Settlements
Transport - Roadways, Railways, Waterways, Airways
Communication
A map is a representation, usually on a flat surface, of the whole or part of an area.

Types of Maps:

Physical Maps: Display the natural features of the earth, such as mountains, plateaus, plains, rivers, oceans, etc.
They use color variations to depict different landforms; for instance, green may be used for plains, brown for mountains, and blue for water bodies.
Political Maps: Show boundaries of countries, states, and districts.
They also depict the location of cities, towns, and villages.
Thematic Maps: Designed to display specific themes.
They could be agricultural maps showing crop patterns, industrial maps depicting industrial areas, or even demographic maps illustrating population distribution.
Topographic Maps: These are detailed and accurate representations of features appearing on the Earth's surface.
They depict natural as well as artificial features like rivers, settlements, roads, etc.
Topographic maps also utilize contour lines to show the shape and elevation of an area.

Distinction between a Map and a Globe

Map: Flat Representation: Maps can be easily carried and can represent a small locality to the entire world.
Detailing: Maps can provide an intricate view of an area, depending on their scale.
Globe: Spherical Representation: A small spherical model of the Earth. It provides an accurate view of continents, oceans, and countries.
Broad Overview: Globes show an overview of the world's features but lack detailed representation.

Maps - What to focus on?

Continents: Large landmasses like Asia, Africa, North America, etc.
Oceans: Major water bodies such as the Pacific, Atlantic, Indian, etc.
Seas: Smaller than oceans but significant, e.g., the Mediterranean Sea, Caribbean Sea, etc.
Countries: Political boundaries delineating nations.
Capital Cities: Major cities which serve as administrative centers for countries.
Rivers: Important waterways like the Amazon, Nile, Mississippi, etc.
Mountains and Mountain Ranges: E.g., the Himalayas, the Rockies, etc.
Lakes: Large freshwater bodies like Lake Victoria, Great Lakes, etc.
Islands: Land masses surrounded by water but smaller than continents.
Deserts: Arid regions such as the Sahara, the Arabian Desert, etc.
Forests: Significant forested regions, often denoted in green, e.g., the Amazon Rainforest.
Latitudinal and Longitudinal Lines: Gridlines that help locate positions (Latitude runs east-west, but measures north-south; Longitude runs north-south but measures east-west).
Equator, Prime Meridian, Tropic of Cancer, and Tropic of Capricorn: Important lines of reference on the globe.

Plains, Plateaus, and Mountains

Plains are large stretches of flat land.

Types of plains:

Alluvial plain: These are created by the deposition of Fertile sediments called Alluvium by rivers and Streams. Example- Indo-Gangetic plains.
Coastal plains: They are formed due to the deposition of sediments carried by rivers as they enter the ocean.
Example- Eastern Coastal Plain and Western Coastal Plain of India.
Structural plain- These are the plains located in the interior of continents and are characterized by the absence of Tectonic activities.
Example- Great plains of North America.
Desert plains- These are created due to erosional activities in Desert areas. They are also called Pedi-plains.
Example- Sahara
Mountains: Elevated landforms higher than the surrounding area, often with steep slopes.
There are three types of mountains- Fold Mountains, Block Mountains, and the Volcanic Mountains.
Fold mountains include:
The Aravali range in India
Himalayan Mountains in Asia
the Alps in Europe
the Andes in South America
the Rockies in North America
the Urals in Russia
Block Mountains: Vindhyas, Satpuras, Black Forest in Germany, Vosges mountain in Germany
Volcanic Mountains: Barren Island, Narcondam Island, Mt.Kilimanjaro in Tanzania, Africa, and Mt.Fujiyama in Japan, Mount St. Helens in North America, Mount Pinatubo in the Philippines, Mount Kea and Mount Loa in Hawaii.

Strait and Isthmus

A strait is a narrow body of water that connects two larger bodies of water.
An isthmus is a narrow strip of land that connects two larger land areas, typically with bodies of water on either side.
It's essentially the land counterpart of a strait, which is a narrow passage of water connecting two larger bodies of water.

Human Environment: Settlement, Transport and Communication

Settlements refer to clusters of dwellings of any type or size where human beings live.
They are organized depending on various factors which influence their size and social structure.

Classification of Settlements:

Based on Size:
Hamlet: A small village.
Village: A clustered human settlement or community, larger than a hamlet but smaller than a town, often rural.
Town: A populated area with fixed boundaries and a local government.
City: A large town, especially one with significant importance in terms of culture, economics, and governance.
Metropolis: A very large and important city, which is a significant cultural, political, or economic center.
Based on Occupation:
Agricultural: Settlements primarily engaged in farming and related activities.
Industrial: Areas where the majority of the population is engaged in industries and manufacturing units.
Trade and Services: Places where people are primarily involved in trading goods and services, which can include urban centers with markets or ports.
Based on Location:
Coastal: Settlements near the sea or ocean.
Forested: Settlements in or around forested regions.
Desert: Settlements in arid regions with scarce vegetation.
Hill: Settlements located in hilly or mountainous regions

Rural Settlement- Types in India:

Clustered, agglomerated, or nucleated,
Semi-clustered or fragmented,
Hamleted, and
Dispersed or isolated.
The clustered rural settlement is a compact or closely built-up area of houses. In this type of village, the general living area is distinct and separated from the surrounding farms, barns, and pastures.
The closely built-up area and its intervening streets present some recognizable pattern or geometric shape, such as rectangular, radial, linear, etc.
Such settlements are generally found in fertile alluvial plains and in the northeastern states.
In Rajasthan, scarcity of water has necessitated compact settlement for maximum utilization of available water resources.

Semi-clustered or fragmented settlements.

In this case, one or more sections of the village society choose or is forced to live a little away from the main cluster or village.
In such cases, generally, the land-owning and dominant community occupies the central part of the main village, whereas people of lower strata of society and menial workers settle on the outer flanks of the village.
Such settlements are widespread in the Gujarat plain and some parts of Rajasthan.

Hamleted Settlements

Sometimes settlement is fragmented into several units physically separated from each other bearing a common name.
These units are locally called panna, para, palli, nagla, dhani, etc. in various parts of the country.
This segmentation of a large village is often motivated by social and ethnic factors.
Such villages are more frequently found in the middle and lower Ganga plain, Chhattisgarh, and lower valleys of the Himalayas.
The dispersed or isolated settlement pattern in India appears in the form of isolated huts or hamlets of a few huts in remote jungles, or on small hills with farms or pastures on the slopes.
Extreme dispersion of settlement is often caused by the extremely fragmented nature of the terrain and land resource base of habitable areas.
Many areas of Meghalaya, Uttaranchal, Himachal Pradesh, and Kerala have this type of settlement.

Urban Settlements

Evolution of Towns in India

Ancient Towns: There are a number of towns in India that have a historical background spanning over 2000 years.
Most of them developed as religious and cultural centers.
Varanasi is one of the important towns among these.
Prayag (Allahabad), Pataliputra (Patna), and Madurai are some other examples of ancient towns in the country.
Medieval Towns: About 100 of the existing towns have their roots in the medieval period.
Most of them developed as headquarters of kingdoms.
These are fort towns which came up on the ruins of ancient towns.
Important among them are Delhi, Hyderabad, Jaipur, Lucknow, Agra and Nagpur.
Modern Towns: The British and other Europeans have developed a number of towns in India.
Starting their foothold on coastal locations, they first developed some trading ports such as Surat, Daman, Goa, Pondicherry, etc.
The British later consolidated their hold around three principal nodes – Mumbai (Bombay), Chennai (Madras), and Kolkata (Calcutta) – and built them in the British style.
For the Census of India 2011, the definition of urban area is as follows;
All places with a municipality, corporation, cantonment board or notified town area committee, etc. (Statutory Towns)
All other places which satisfied the following criteria:
A minimum population of 5,000;
At least 75 percent of the male main working population engaged in non-agricultural pursuits; and
A density of population of at least 400 persons per sq. km.
The Census of India classifies urban centers into six classes
The Metropolitan cities are those Indian cities having a population of more than 4 million.
A megacity is usually defined as a metropolitan area with a total population in excess of 10 million people

Functional Classification of Towns

Administrative towns: Towns supporting administrative headquarters of higher order are administrative towns, such as Chandigarh, New Delhi, Bhopal, Shillong, Guwahati, Imphal, Srinagar, Gandhinagar, Jaipur Chennai, etc.
Industrial towns: Industries constitute the prime motive force of these cities such as Mumbai, Salem, Coimbatore, Modinagar, Jamshedpur, Hugli, Bhilai, etc.
Transport Cities: They may be ports primarily engaged in export and import activities such as Kandla, Kochi, Kozhikode, Vishakhapatnam, etc., or hubs of inland transport such as Agra,
Commercial towns: Towns and cities specializing in trade and commerce are kept in this class. Kolkata, Saharanpur, Satna, etc. are some examples.
Mining towns: These towns have developed in mineral-rich areas such as Raniganj, Jharia, Digboi, Ankleshwar, Singrauli, etc.
Garrison Cantonment Towns These towns emerged as garrison towns such as Ambala, Jalandhar, Mhow, Babina, Udhampur, etc.
Educational towns: Starting as centers of education, some of the towns have grown into major campus towns such as Roorkee, Varanasi, Aligarh, Pilani, Allahabad, etc.
Religious and cultural towns: Varanasi, Mathura, Amritsar, Madurai, Puri, Ajmer, Pushkar, Tirupati, Kurukshetra, Haridwar, and Ujjain came to prominence due to their religious/cultural significance.
Tourist towns: Nainital, Mussoorie, Shimla, Pachmarhi, Jodhpur, Jaisalmer, Udagamandalam (Ooty), and Mount Abu are some of the tourist destinations.

Transport - Roadways, Railways, Waterways, Airways (6:40 PM)

Roadways

The National Highways constitute only two percent of the total road length but carry 40 percent of the road traffic.
State Highways are constructed and maintained by state governments. They join the state capitals with district headquarters and other important towns. These roads are connected to the National Highways.
States Highways constitute 3 percent of the total road length in the country
District roads are the connecting link between District Headquarters and the other important nodes in the district. They account for about 10 percent of the total road length of the country
National Highways are numbered as follows:
All north-south oriented highways will have even numbers increasing from the east to the west.
All east-west oriented highways will have odd numbers increasing from the north to the south.
All major Highways will be single-digit or double-digit in number

Roadways

Road Networks: Include local roads, highways, and expressways. They play a vital role in connecting rural and urban regions.
National Highways are numbered as follows:
All north-south oriented highways will have even numbers increasing from the east to the west.
All east-west oriented highways will have odd numbers increasing from the north to the south.
All major Highways will be single-digit or double-digit in number
The Golden Quadrilateral (GQ) is a major highway network in India that connects four of the most significant metropolitan cities: Delhi (North), Mumbai (West), Chennai (South), and Kolkata (East).
Other cities connected by this network include Ahmedabad, Bengaluru, Baleshwar (Balasore), Bhubaneswar, Cuttack, Berhampur, Durgapur, Jaipur, Kanpur, Pune, Kolhapur, Surat, Vijayawada, Ajmer, Vizag, Bodhgaya, Varanasi, Allahabad, Agra, Mathura, Dhanbad, Gandhinagar, Udaipur, and Vadodara

Bharatmala Project

Bharatmala Pariyojana (2015) is an umbrella program for the highways sector envisaged by the Ministry of Road Transport and Highways (MoRTH)
Under Phase-I of Bharatmala Pariyojana, the implementation of 34,800 km of national highways in 5 years (from 2017 to 2022) was approved at an estimated outlay of Rs. 5,35,000 crore.
Objectives
Connecting 550 Districts in the country through NH linkages.
Optimizing the efficiency of the movement of goods and people across the country.
Generating a large number of direct and indirect employment opportunities in the construction & infrastructure sector and also as part of the enhanced economic activity resulting from better road connectivity across the country.

Railways

The Diamond Quadrilateral (2014 origin) is a project initiated by the Government of India to connect the major cities with a high-speed rail network.
This ambitious project aims to establish a high-speed train corridor, similar in spirit to the Golden Quadrilateral for highways, connecting the four major metro cities of India: Delhi, Mumbai, Kolkata, and Chennai

Dedicated Freight Corridor (DFC)

It is a high-speed and high-capacity railway corridor that is exclusively meant for the transportation of freight, or in other words, goods and commodities.

Waterways

It includes rivers, canals, seas, and oceans
To promote Inland Water Transport (IWT) in the country, 111 waterways (including 5 existing and 106 new) have been declared as National Waterways (NWs) under the National Waterways Act, 2016.
The Inland Waterways Authority of India (IWAI) was constituted under the IWAI Act, 1985 for the development and regulation of inland waterways for shipping and navigation.

Sagarmala Project

The Sagarmala Programme was approved by the Union Cabinet in 2015 which aims at holistic port infrastructure development along the 7,516-km long coastline through modernization, mechanization, and computerization.
It is under the Ministry of Ports, Shipping and Waterways (MoPSW)
The vision of the Sagarmala Programme is to reduce logistics costs for EXIM (Export-Import) and domestic trade with minimal infrastructure investment.
Sagarmala could boost India’s merchandise exports to USD 110 billion by 2025 and create an estimated 10 million new jobs (four million in direct employment).
Ports in India
Major ports
Minor ports

Types of port according to cargo handled:

(i) Industrial Ports: These ports specialize in bulk cargo like grain, sugar, ore, oil, chemicals, and similar materials.
(ii) Commercial Ports: These ports handle general cargo-packaged products and manufactured goods. These ports also handle passenger traffic.
(iii) Comprehensive Ports: Such ports handle bulk and general cargo in large volumes.
Types of port on the basis of location:
(i) Inland Ports: These ports are located away from the sea coast. They are linked to the sea through a river or a canal. Such ports are accessible to flat-bottom ships or barges.
For example, Manchester is linked with a canal; Memphis is located on the river Mississippi; Rhine has several ports like Mannheim and Duisburg; and Kolkata is located on the river Hoogli, a branch of the river Ganga.
(ii) Out Ports: These are deep water ports built away from the actual ports. These serve the parent ports by receiving those ships that are unable to approach them due to their large size. A classic combination, for example, is Athens and its outport Piraeus in Greece.

Types of port on the basis of specialized functions:

(i) Oil Ports: These ports deal in the processing and shipping of oil. Some of these are tanker ports and some are refinery ports. Maracaibo in Venezuela, Esskhira in Tunisia, and Tripoli in Lebanon are
tanker ports. Abadan on the Gulf of Persia is a refinery port.
(ii) Ports of Call: These are the ports that originally developed as calling points on main sea routes where ships used to anchor for refueling, watering, and taking food items. Later on, they developed into commercial ports. Aden, Honolulu, and Singapore are good examples.
(iii) Packet Station: These are also known as ferry ports. These packet stations are exclusively concerned with the transportation of passengers and mail across water bodies covering short
distances. These stations occur in pairs located in such a way that they face each other across the water body, e.g. Dover in England and Calais in France across the English Channel.
(iv) Entrepot Ports: These are collection centers where the goods are brought from different
countries for export. Singapore is an entrepot for Asia. Rotterdam for Europe, and Copenhagen for the Baltic region.
(v) Naval Ports: These are ports which have only strategic importance. These ports serve warships and have repair workshops for them. Kochi and Karwar are examples of such ports in India.

Airways

Indira Gandhi International Airport, New Delhi
Chhatrapati Shivaji Maharaj International Airport, Mumbai, Maharashtra
Kempegowda International Airport, Bengaluru, Karnataka
Chennai International Airport, Chennai, Tamil Nadu
Netaji Subhas Chandra Bose International Airport, Kolkata, West Bengal
Rajiv Gandhi International Airport, Hyderabad, Telangana
Cochin International Airport, Kochi, Kerala
Sardar Vallabhbhai Patel International Airport, Ahmedabad, Gujarat
Goa International Airport, Dabolim, Goa
Pune International Airport, Pune, Maharashtra
Trivandrum International Airport, Thiruvananthapuram, Kerala
Lokpriya Gopinath Bordoloi International Airport, Guwahati, Assam
Sri Guru Ram Dass Jee International Airport, Amritsar, Punjab
Biju Patnaik International Airport, Bhubaneswar, Odisha
Calicut International Airport, Kozhikode, Kerala

Topics for the next lecture - Atmosphere, Continent, Oceans