Geography

Soil Formation, Profile & Characteristics

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Soil Formation, Profile & Characteristics

This article deals with ‘Soil Formation, Profile & Characteristics ’ This is part of our series on ‘Geography’ which is an important pillar of the GS-1 syllabus. For more articles, you can click here

Introduction

  • Soil is the uppermost layer of the earth’s crust which can support plant life, and is usually composed of minerals, organic matter, living organisms, air and water.
  • Naturally occurring soil is influenced by the following factors
Parent rock Climate
Relief Physical, Chemical & Biological agents
Land use practice Time

How is Soil formed?

  • Soil formation begins with volcanic sedimentary or metamorphic rock material and can be seen in operation at an early stage on a recently formed volcanic island. 
  • Rock is colonized by plants, suited to bare rocks like lichens and mosses, happens. 
  • It is followed by the decay of plant material and the development of a thin organic layer on the rock.
  • Wind, rain, snow and freezing cause erosion and rock fracturing, leading to more colonization and physical breakdown of the rock materials.
  • After thousands of years, the upper layer of rocks will be converted into soils of many types.

Soil Profile

Soil development begins with the colonization of parent rock by plants and animals. Due to various factors of erosion and transportation, different layers with different physical and chemical properties are formed. These are known as soil profile or horizons.

Soil Formation, Profile & Characteristics

O-Horizon

  • O-horizon is very common to surfaces with lots of vegetative cover. It is the layer made up of organic materials such as dead leaves and surface organisms, twigs and fallen trees.

A-Horizon

  • A-Horizon is called Top Soil.
  • It is rich in minerals as well as humus.
  • Humus is generated by the decay of organic matter in the O horizon is carried downward by percolating water to enrich the A horizon.
  • A horizon is dark because of a concentration of decomposed organic matter.

E-Horizon

  • E-Horizon is usually lighter in colour
  • This layer is rich in nutrients which are leached downwards from A and O horizons.

B-Horizon

  • It is called Subsoil.
  • It lies below the E-horizon 
  • Most of the nutrients taken from the A and E horizons are deposited in this zone of accumulation.
  • B horizon generally has little humus.

C-Horizon

  • C-Horizon is the weathered parent rock.
  • This layer is the first step in the development of soil and eventually gives rise to the top two layers. 

R-Horizon

  • It is the unweathered parent rock.

Factors affecting Soil formation

Parent Rocks

  • Soil is formed by the erosion of the parent rock. Hence, soil inherits many properties from the parent material.
  • E.g., In Deccan Plateau, Black coloured soil is found as it is derived from lava rocks. At the same time, the alluvial soil of the Northern plains is different from in-situ rocks as its parent rocks are Himalayan rocks.

Climate

Soil formation also depends on how long these have been affected by a particular climate. E.g.,

  1. Precipitation impacts the soil in the following ways
    • In regions receiving high precipitation, nutrients leach downward, reducing soil fertility (lateritization and podzolization).
    • Salts accumulate in the soil in arid regions due to excessive evaporation and capillary action. 
  2. Temperature directly affects the activity of soil microorganisms. Hence, 
    • In the cool regions (between 0 to 10 °C), there is retarded microorganism activity. Thus, the decomposition of organic material occurs at a lower rate, and thick O-Horizon forms due to the accumulation of organic matter. This organic material turns to humus, which percolates downwards, resulting in organic matter in A Horizon as well. 
    • In warm & wet tropics, microorganisms rapidly decompose the organic material. Hence, O-Horizon cannot develop properly, and the whole posit profile lacks organic matter.
  3. The density of vegetation depends on the climate of the region, which impacts soil formation. 
    1. Dense vegetation in a wet climate
      • The dense vegetative cover protects soil from being removed through erosion by running water or wind. Hence, a thick layer of soil develops in these regions.
      • Forests form a protective canopy which prevents heat and rain from directly impacting soil.
      • In areas of dense vegetation, the moisture content in the soil is high due to the action of roots 
    2. Sparse vegetation in an arid climate
      • In the case of sparse vegetation, soil evaporation will be more than in the case of thick protective vegetation. This evaporation, in turn, increases the movement of capillary water toward the surface leading to higher soil salinity.

Relief

  • The run-off is fast in hilly areas with steep slopes, and the soil keeps sliding. Hence, soil horizons are thick on gentle slopes and thin on steep slopes.
  • Along with that, slopes that face away from the Sun have cool-moist soil as they are sheltered from direct insulation. On the other hand, slopes that face the Sun receive direct solar rays, resulting in increased evapotranspiration. 

Biota

  • Vegetation is an important factor as
    1. It acts as a source of organic matter and humus in the soil. Hence, some of America’s richest soils developed in the Middle West prairies under a thick grass cover.
    2. Roots of vegetation help in breaking the rocks
    3. Legumes and certain other plants help in the fixation of atmospheric nitrogen in the soil 
  • Many organisms, from bacteria to burrowing animals, are found in soil. E.g., Earthworms continuously repair the soil by burrowing and moving it through their intestines. They ingest large amounts of decaying leaf matter, carry it down from the surface, and incorporate it into the mineral soil horizons.

Time

  • Time is of great importance in the development of soil. Humus and organic matter are added to the soil every year, and soil fertility continues to increase. However, the process continues for thousands and thousands of years before good-quality soil is formed.

Transportation of Minerals in Soil 

Laterization

  • Laterization is a soil-forming regime that occurs in humid tropical areas with high temperatures and abundant precipitation.
  • The soil in this type of climate does not have an O-horizon (because of the rapid decomposition of organic material by microorganisms), and most of the minerals and silica of A horizon are leached downwards except for iron and aluminium compounds, which are insoluble primarily because of the absence of organic acids. 
  • B horizon of Laterite soils is enriched in all the leached materials like silica.
  • Lateritic soils are generally reddish in colour due to the presence of iron oxides
Laterization

Podzolization

  • Podzolization occurs mainly in the high middle latitudes where the climate is moist and cool.
  • The soil in this type of climate has a thick O-horizon because, due to low temperatures, microorganism activity is reduced enough that humus accumulates. When water percolates downwards through the O-Horizon, it becomes acidic due to the formation of an Organic Acidic solution.
  • Leaching by organic acidic solutions removes the soluble bases and aluminium and iron compounds from the A horizon leaving behind silica. The remaining silica gives a distinctive ash-grey colour.
Podzolization

Calcification

  • In contrast to laterization and podzolization, which require humid climates, this occurs in arid regions with high temperatures where evaporation significantly exceeds precipitation.
  • In arid regions, B horizon has high levels of Calcium. When water is evaporated from the upper layers of soil in these regions, water from the lower layers of soil mixed with Calcium comes up by capillary action. Hence, the proportion of calcium salts increases and soil salinity increases. 

Characteristics of Soil

1. Colour

  • Soil colour might not be the most important attribute of soil, but it is certainly the most visible.
  • A soil’s colour offers a clue to its physical and chemical characteristics
  • E.g.: 
    1. Humus is black or brown, and soils with a high humus content tend to be dark. As soil’s humus content decreases because of either low organic activity or its loss by high microbiological activities, soil colours gradually fade to light brown or grey.
    2. Reddish soil usually indicates that iron is present in the soil.
    3. In cold-moist climates, a light grey soil indicates that iron has been leached out, leaving oxides of silicon  

2. Texture

oil texture refers to the size of grains that make up soil. Soil grains can be of the following types

Clayey Grains have a diameter of less than 0.002 millimetres
Silt Grains have a diameter between 0.002 to 0.05 millimetres
Sandy Grains have a diameter between 0.05 to 2.0 millimetres
Gravel / Pebble Grains have a diameter above 5 millimetres

Soil texture helps determine a soil’s capacity to retain the moisture and air necessary for plant growth. 

  1. Soils with a higher proportion of larger grains (i.e. sandy soils) have many small passages between touching mineral grains, which allow water to seep downwards. They are well aerated as the space between the grains is occupied by air. But they allow water to seep through so quickly that plants cannot use it. 
  2. Clay soils present the opposite problem. They have fine particles, resulting in smaller passages and spaces, so water penetrates slowly, and soils become waterlogged. But at the same time, they are deficient in air

Soils can be classified based on their proportion of sand, silt, and clay. Loam soils occupy the central areas of the triangular diagram. Loam is soil that contains a proportion of each of the three grades and, as a result, is most effective at storing moisture and air. This mixture is often added to gardens because it is particularly suitable for plant growth. Depending on which grade is dominant, loams can be further classified as sandy, silty, or clay-rich.

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3. Soil Structure

  • oil structure refers to the way soil grains are clumped together into larger masses called peds.
  • Along with soil texture, soil structure also determines the permeability of water. Soils with the same texture but different structures can have different water permeability. 
  • Soil structure can be of the following type
Granular structure  – Small peds, shaped roughly like spheres, give the soil a granular structure.
– They are loosely packed and found in the surface layers, along with organic material and roots.
Blocky Structure – Larger peds form an angular, blocky structure
– These are typical of B-horizons
Palty structure Platy structure tends to indicate compaction of the soil by animals or human activities 
Columnar structure A columnar structure can occur in arid or sandy soils.
Soil Structure

4. Soil Acidity and Alkalinity

  • Soil pH is an important indicator of soil fertility as soil acidity, or alkalinity helps determine nutrient availability for plant growth.

Why is soil acidity important for the fertility of soil?

  • Since plants receive virtually all their nutrients in solution, they can only absorb nutrients dissolved in liquid. However, if the soil moisture lacks some degree of acidity or is basicity, soil water has little ability to dissolve these nutrients. As a result, even though nutrients are in the soil, plants may not have access to them. 
  • To correct alkalinity, which is common in the soils of arid regions, farmers can flush the soil with irrigation water. 
  • Strongly acidic soils are also detrimental to plant growth. In acidic soils, soil moisture dissolves nutrients, but they may be leached away before plant roots can absorb them. Soil acidity can be corrected by adding lime to the soil.

Plantation Crops of India

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Last Updated: Jan 2025 (Plantation Crops of India)

Plantation Crops of India

This article deals with ‘Plantation Crops of India  ’ This is part of our series on ‘Geography’, which is an important pillar of the GS-1 syllabus. For more articles, you can click here.

Introduction

  • Plantation crops are grown for the purpose of export. In India, they are generally grown in large estates on sloping hills.
  • The main plantation crops grown in India are tea, coffee, rubber, and spices. 

1. Tea

  • Tea is an evergreen plant that mainly grows in tropical and subtropical climates.
  • Tea is made from dried leaves of the tea plant. When added to boiling water, the theine in it serves as a stimulant.
  • There are at least 6 different types of Tea
    1. White Tea: Wilted and unoxidized
    2. Yellow Tea: Unwilted and unoxidized
    3. Green Tea: Unwilted and unoxidized
    4. Oolong Tea: Wilted, bruised and partially oxidized
    5. Black Tea: Wilted /sometimes crushed
    6. Post-fermented: Allowed to ferment / compost.

History

  • Although Tea is said to be indigenous to China, Major Robert Bruce noted in 1823 that tea bushes grew freely on the slopes of upper Assam’s hills.
  • In 1840, tea seeds were smuggled out of China, and commercial tea plantations were set up in the Brahmaputra valley. 
  • Presently, India is second largest producer and the fourth largest tea-exporter in the world.
  • Tea industry employs 1.16 million people directly.

Conditions required for growing Tea

Temperature The ideal temperature for its growth is 20-30°C. But temperatures above 35°C and below 10°C harm the bushes.
Annual Rainfall 150-300 cm well distributed throughout the year.
Specific factors – Heavy dew and morning fog favour the rapid development of young leaves.
– Tea is a shade-loving plant and develops rapidly when planted with shady trees.
– Although Tea requires heavy rainfall, stagnant water is detrimental to its roots. Therefore, it is grown on hill slopes where water drains away easily. But nevertheless, if drainage is good, it grows equally well in the valley.
Soil Well drained, rich in humus and iron content soils.
Labour required Tea is labour intensive crop. Cheap and skilled labour is required at the time of plucking the tea leaves. 

Producer States

In India, it is mainly grown in 

  • North East India (Assam (51%) and Darjeeling hills of West Bengal (22%))
  • South India (Nilgiri hills, Cardamom, Palani and Anaimalai Hills) 
  • North-West India (Kangra Valley and Mandi of Himachal Pradesh and Dehradun, Almora and Garhwal district of Uttarakhand)

Note: Green Tea is produced in the Kangra Valley of Himachal Pradesh.

Plantation Crops of India

Side Topic: Darjeeling Tea

  • Darjeeling Tea of India is famous worldwide for its unique aroma and taste.
  • It has the GI Tag (in fact, it was the first product from India which was granted the GI Tag).

2. Coffee

  • Coffee is a brewed beverage made from roasted coffee beans.
  • The genus ‘Coffea’ is native to Tropical Africa.
  • There are two main varieties of coffee. They are
    1. Arabica (High quality): 49% of the area under coffee cultivation in India is Arabica 
    2. Robusta (Inferior quality): 51% of the area under coffee cultivation in India is Robusta

History

  • The history of coffee in India dates back to around 1600 AD when the Indian Sufi saint named Baba Budan went on a pilgrimage to Mecca. He took seeds of coffee from Mocha, a port city in Yemen, and after returning from his pilgrimage, planted seven seeds of Mocha in his courtyard in Chikmagalur. The coffee plants gradually spread to hills now known as Baba Budan Hills. 

Conditions required for growing Coffee 

The coffee plant requires very specific conditions.

Temperature Varying between 20-27°C (It requires a high temperature and humid climate for rapid growth but a cold and dry climate for ripening of berries)
Rainfall Abundant rainfall between 100 to 200 cm
Specific conditions – Direct sunlight is harmful to coffee plants. Therefore, these are planted in the shade of taller trees, such as bananas. 
– They require well-drained land, as stagnant water is harmful to coffee plants. Hence, it is grown on slopes receiving orographic rainfall and having a height between 600 m to 1,800 m because these are well-drained and cooler. 
Labour required Large labour is required because coffee is to be hand-picked.

Producer States

  • India is the 8th largest producer of coffee globally. (Brazil is the largest producer contributing to 40% of global production).
  • India produces 2.5 % of the world’s coffee. 
  • Karnataka (71%), Kerala (22%) and Tamil Nadu (7%) are the leading producers of coffee in India. 
  • In 2024, Coffee exports from India has gone above $1 billion compared to $460 million in 2021. European Union followed by UAE and US are the major importers of Indian Coffee.
Coffee growing areas of India

3. Rubber

  • Rubber is a coherent elastic solid obtained from latex. 
  • A rubber tree is a quick-growing tall tree acquiring 20-30 m height in 5 to 7 years after planting.
  • Rubber is used for various purposes like tyres, tubes, erasers and industrial products.
  • The first rubber plantations in India were set up in 1895 on the hill slopes of Kerala. 

Conditions required for growing Rubber 

Temperature High temperature between 25 to 35°C
Rainfall High rainfall of above 200 cm, distributed around the year
Soil – Deep well, drained loamy soils on the hill slopes at an elevation ranging from 300 to 450 m above sea level. But yield starts to decline at higher elevations, and no rubber plantations are found above 700 m.  
– Soil should be acidic, with a pH in the range of 4.5 to 6.0.
– Soil should be deficient in phosphorus.
Specific conditions Daily rain followed by a strong sun is beneficial.
Labour required Large labour is required for making a cut and collecting rubber milk. Hence, cheap and abundant labour must be available.

Producer States

In India, it is produced in Kerala (92%), Tamil Nadu (3%), Kerala (2%) and Andaman and Nicobar (~2%).

Rubber growing areas of India

4. Spices

  • India has been world-famous for its spices since ancient times. 
  • These spices are mostly used for flavouring cooked food and for preparing medicines, dyes etc. 
  • Pepper, chillies, turmeric, ginger, cardamom, clove and areca nut are the major spices cultivated in India. 
  • Kerala is the leading producer of spices in India.  

Cash Crops of India

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Last Updated: Jan 2025 (Cash Crops of India)

Cash Crops of India

This article deals with ‘Cash Crops of India ’ This is part of our series on ‘Geography’, which is an important pillar of the GS-1 syllabus. For more articles, you can click here.

Introduction

  • The crops which are cultivated for commercial purposes are called cash crops.
  • These crops include sugarcane, tobacco, fibre crops (cotton and jute), tea, coffee and oilseeds.

Sugarcane

  • Sugarcane is India’s most important cash crop, and India is the second largest producer of sugarcane globally.
  • This crop provides the raw material for the sugar industry.
  • Besides providing sugar, gur and khandsari, it supplies molasses for the alcohol industry and bagasse for the paper industry.

Conditions required for growing Sugarcane 

Temperature High temperature between 21 to 27°C  
Annual Rainfall Humid climate with rainfall between 75 to 150 cm  
Specific conditions – In the latter half, the temperature around 20 °C and the open sky help in acquiring juice and thickening.
– While too heavy rainfall results in low sugar content, deficiency in rainfall produces a fibrous crop
– A short cool, dry winter during ripening and harvesting are ideal. 
– Frost is detrimental to sugarcane, and it must be harvested before frost season.   
Soil – Deep rich loamy soil is ideal.
– Soil that can retain moisture.
– Soil should be rich in nitrogen, calcium and phosphorous.
– Sugarcane exhausts soil fertility quickly and extensively, and its cultivation requires heavy doses of manures and fertilizers.  
Labour required – It is a labour-intensive crop.
– Cheap and abundant labour is a prerequisite.

Producer States

At the state level, Uttar Pradesh is the leading producer of sugarcane, followed by Maharashtra, Karnataka, Tamil Nadu, Gujarat, Punjab, Haryana and parts of MP and Bihar.

Cash Crops of India

Traditionally sugarcane areas were northern plains, especially UP. But its cultivation has gradually shifted towards the south.  The reason for this is the fact that North Indian sugarcane is :

  • Subtropical variety 
  • Low sugar content 
  • Sugar factories are shut in winter as sugarcane is grown only in summer.  

Hence, when irrigation developed in the southern states, the sugarcane industry developed there as well.

2. Cotton

  • Cotton is the most important cash crop in India. 
  • It provides raw materials to India’s most significant industry, i.e. Textile Industry. 
  • Besides the cotton fibre, its seed acts as raw material in the Vanaspati industry. Additionally, cotton seed can be used as fodder for milch cattle.
  • India ranks second next to China in the production of cotton.

Conditions required for growing Cotton 

Cotton is a tropical and subtropical crop requiring uniformly high temperatures. Conditions for its growth are 

Temperature – Uniformly high temperatures between 21 to 30° C
– Its growth is retarded when the temperature falls below 20°C.
– Frost is its enemy, and it is grown in areas having at least 210 frost-free days.
Annual Rainfall – Modest requirements varying between 50 to 100 cm
– However, it is successfully grown in areas with lesser rainfall with irrigation’s help.
– Moist and heavy rainfall during boll opening and picking is detrimental as plants become vulnerable to pests and diseases. 
Soil – Best suited soil is the Black soil of the Deccan and Malwa plateaus.
– It can also grow in the alluvial soils of the Northern Plains and Laterite soils of Peninsular India.
– Cotton quickly exhausts the fertility of the soil. Hence, regular application of manure and fertilizer is necessary.
Labour required Cotton picking is not yet mechanized and requires cheap and efficient labour.

Varieties of Cotton

There are three main varieties of cotton grown in India. 

1. Long Staple Cotton

  • It has the longest fibre, with lengths varying from 24 to 27 mm.
  • The fibre is long, fine and shining and is used for making fine and superior-quality cloth.
  • 50% of the total cotton produced in India is of this variety.
  • It is grown in Punjab, Haryana, Maharashtra, Tamil Nadu, MP, Gujarat and Andhra Pradesh.

2. Medium Staple Cotton

  • The length of its fibre is between 20 to 24 mm.
  • 44% of the total cotton produced in India is of this variety.
  • It is grown in Punjab, Tamil Nadu, Madhya Pradesh, UP, Karnataka and Maharashtra.

3. Short Staple Cotton

  • It is an inferior variety whose length is less than 20 mm. 
  • About 6% of the cotton grown in India is of this type.

Producer States

Leading producer states include Gujarat (35%), Maharashtra (21%), Andhra (14%), Haryana (8%), Punjab (7%), MP (6%), Rajasthan (4%) and Karnataka (3%).

Cotton Growing Areas in India

3. Jute

  • Jute, also known as ‘Golden Fibre’, is an important cash crop.
  • It provides the raw material for the Jute industry. It is used to manufacture gunny bags, carpets, hessian, ropes and strings, rugs, clothes, tarpaulins, upholstery etc. 
  • It has high tensile strength and low extensibility and ensures better breathability of fabrics.
  • It is 100% bio-degradable and recyclable and thus environmentally friendly. 

Conditions required for growing Jute 

It is a tropical fibre crop and requires the following conditions

Temperature High temperature varying between 24 to 35°C 
Annual Rainfall – Heavy rainfall of 120 to 150 cm with 80 to 90% relative humidity
– A large quantity of water is required to grow the jute crop and process the fibre after the crop is harvested. 
Soil – Light sandy and clayey loams.
– Jute rapidly exhausts the fertility of the soil, and the soil must be replenished annually by the silt-laden flood water of the rivers. 
Labour required A large supply of cheap labour is required to grow and process jute fibre.

Producer States

  • India suffered a great setback during the partition of India in 1947 because 75% of the jute growing areas went to Bangladesh while the jute mills remained in India. The government has made great efforts to increase the production and area under jute in India.
  • The main producer states in India include West Bengal (80% production), Bihar, Assam and Odisha.
Jute Growing Areas in India

4. Oil Seeds

  • Oilseeds are a very important group of the commercial crop in India, and oil extracted from oilseeds is an important item of our diet and used as raw material for many items like paints, varnishes, hydrogenated oil, soap, perfumery, lubricants etc.
  • Oil cake, the residue after oil is extracted from the oilseed, is used as cattle feed and manure. 
  • India is the largest producer of oilseeds in the world. But production of oilseed has always fallen short of our demand, and there has always been a need to import oilseeds. 
  • Nine major oilseeds grown in India are groundnut, sesamum, rapeseed and mustard, linseed, safflower, castor seed, sunflower and soybean. 

Groundnut

  • It is the most important oilseed in India.
  • India is the second largest producer.
  • It constitutes 50% of the oilseed production of India.
  • It contains 40-50% oil.
  • Use: Mainly as edible oil. It can also be eaten in raw form. Its oil cake is used as cattle feed.
  • It synthesizes atmospheric nitrogen and increases the fertility of the soil.
  • It requires 20-30°C temperature, 50-75 cm rainfall and well-drained light sandy loan, red, yellow and black cotton soil.
  • It is mainly grown in Andhra Pradesh, Tamil Nadu, Gujarat, Rajasthan, Karnataka and Maharashtra.

Sesamum (Til)

  • India has the world’s largest area under sesamum.
  • It contains 45-50% oil.
  • Use: Mainly as edible oil. Sesamum seeds can also be eaten in a fried form mixed with sugar or gur. Its oil cake is used as cattle feed.
  • It grows well in areas having 21-23°C temperature, 45-50 cm rainfall and well-drained light loamy soils. 
  • Sesamum is grown in all parts of the country, but West Bengal is the largest producer producing 33% of the produce. Other significant producers are Gujarat, Rajasthan, Maharashtra, Tamil Nadu and Karnataka. 

Mustard and Rapeseed

  • It is the most important oilseed next to groundnut.
  • It contains 25-45% oil.
  • Use: Mainly used as edible oil. Its oil is also used for pickles, lubricants and toiletries. Its oil cake is used as cattle feed.
  • Like wheat and gram, they thrive only in the cool climate of the Satluj-Ganga plain.
  • Its major producers include Rajasthan (46%), Haryana, MP, YP, West Bengal, Gujarat, Punjab etc. 

5. Tobacco

  • Tobacco was brought to India by the Portuguese in 1508. since then, its cultivation has spread to different parts of the country. At present, India is the major producer of tobacco in the world.
  • Apart from oral consumption, tobacco is mainly used for cigarettes, bidi, cigars and hookah. It is also used in the production of insecticides. 
  • There are two varieties of tobacco. These include
    1. Nicotiana Tabacum: High-quality tobacco used in cigarettes, cigar bidi, chewing, hookah and pipe. 90% of tobacco grown in India is of this variety. 
    2. Nicotiana Rustica: Inferior and short quality used in hookah, chewing and snuff. 10% of tobacco grown in India is of this variety.

Conditions required for growing Tobacco 

Conditions for the growth of tobacco includes

Temperature Wide range varying from 16 to 35°C.
Annual Rainfall From 50 to 100 cm of rainfall. But the rainfall should be well distributed throughout the year. Irrigation is required if the rainfall is low or erratic.
Specific factors Frost is injurious to its growth.
Soil Well-drained sandy loam, not too rich in organic matter.
Labour required Cheap and abundant labour is required at all stages of cultivation.

Producer States

It is grown in 15 states of India. But 66% of production comes from Gujarat and Andhra Pradesh. 

Tobacco growing areas in India

Food Crops of India

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Last Updated: Jan 2025 (Food Crops of India)

Food Crops of India

This article deals with ‘Food Crops of India ’ This is part of our series on ‘Geography’ which is an important pillar of the GS-1 syllabus. For more articles, you can click here

Introduction

  • Due to its large population and limited land, Indian agriculture is largely dominated by food crops.
  • Food crops include cereals and pulses, amongst which rice, wheat, jowar, bajra, maize, barley, ragi, gram and tur are important.

1. Rice

  • Rice is an indigenous crop and staple food of the majority of Indians.
  • After China, India is the second-largest rice producer in the world.

Conditions required for growing Rice

Temperature It is a tropical crop, growing with mean temperatures of 24°C.
Annual Rainfall Require high rainfall above 150 cm. It can be grown with the help of irrigation facilities in low-rainfall areas
Soil Deep fertile clayey, or loamy soils
Labour required Labour-intensive crop requiring an abundant supply of cheap labour
Important Varieties IR-8, Jaya, Padma, Hamsa, Krishna, Sabarmati, IET 1039, CR Dhan 205, AR Dhan 306, CRR 451 etc.

Producer States 

  • West Bengal (largest producer in India), UP, Punjab, Tamil Nadu, Bihar, Andhra, Odisha, Assam, & Haryana.
Food Crops of India

Issues associated with its cultivation

  • Due to the increased use of High Yielding Variety (HYV) seeds (CR Dhan 205, AR Dhan 306, CRR 451 etc.), many indigenous varieties have disappeared.
  • It is a water-guzzling crop grown in arid regions like Punjab and Haryana with the help of tubewell irrigation. It has led to a rapid downfall in the groundwater level.

2. Wheat

  • Wheat is the country’s second most important food crop, after rice.
  • India ranks 5th in the production of wheat in the world. 

Conditions required for growing Wheat 

Temperature Wheat requires a cold and moist climate at the time of sowing and a warm and dry climate at the time of ripening (10-15°C at the time of sowing and 20-25°C at the time of ripening of grains.)  
Rainfall – Requires less rainfall than rice ranging between 50 to 75 cm
– Western disturbances in North India significantly help wheat production by providing the required moisture in a cold climate.
– In drier regions, it can be grown with the help of irrigation.
Soils Well-drained clayey or loamy soil
Important varieties Sonalika, Kalyan, Sona, Sabarmati, Lerma, Roso, Heera, Shera, Sonara-64.

Producer States

  • Over 85% of India’s wheat production comes from 5 states, namely Uttar Pradesh (highest producer), Punjab (highest yield per hectare), Haryana, Rajasthan and Madhya Pradesh. 
  • Apart from these regions, the black soil tract of the Deccan covering parts of Maharashtra and Gujarat also grows wheat.
Wheat growing regions of India

3. Millets – Bajra, Jowar and Ragi

  • In this too,
    • Bajra is grown mainly in North India.
    • Jowar is grown mainly in Peninsular India 
    • Ragi is grown mainly in South India.
  • Millets have high nutritional value. 

Bajra

  • It is a coarse grain and forms the staple food for poor people. Its stalks are used as fodder for cattle and for thatching purposes.
  • Bajra is a crop in warm and dry regions.

Conditions required for growing Bajra 

Temperature  High temperatures ranging between 25 to 30°C
Rainfall They can grow well in low rainfall of up to 45 cm.
Soils Sandy soils and shallow black soil

Major Producers

  • It includes
    1. Arid regions like Rajasthan (the largest producer)
    2. Rain shadow regions of Maharashtra, Madhya Pradesh and Gujarat.  
  • Note: In Punjab, millets, especially Bajra, were grown earlier. But with the development of irrigation facilities, farmers of Punjab have adopted highly productive crops like wheat and rice in place of low-productive crops like Bajra. Therefore, a sharp decline has been noticed in the cropped area under crops like Bajra in the last few decades.

Jowar

  • Jowar is the third important food crop of our country. 
  • Although a coarse grain, it is rich in carbohydrates, protein, minerals, and vitamins. Hence, it provides cheap food to a large section of the poor population.

Conditions required for growing Jowar 

Jowar has a tendency to grow even in adverse climatic conditions. Basically, they are warm and dry climate crops.

Temperature It grows in high temperatures within a wide range of 20 to 32°C.
Rainfall It can grow well even in low rainfall of up to 30 cm.
Soils Black and Red soil

Major Producers

  • Jowar is essentially a crop of Peninsular India.
  • Maharashtra, Karnataka, and Madhya Pradesh are the leading producers of Jowar

Ragi

  • Ragi is a coarse grain but very rich in iron, calcium, other micro-nutrients and roughage.

Conditions required for growing Ragi 

They grow well in warm and dry climates. 

Temperature They grow in a warm climate
Rainfall They grow well in arid regions
Soils Red, Sandy, Loamy and Shallow Black soils.

Major Producers

  •  Karnataka is the largest producer of Ragi, followed by Tamil Nadu.

Benefits of Millets

Considering the benefits of Millets, FAO has decided to celebrate 2023 as the ‘UN International Year of Millets‘.

1. Climate Smart

  • They are climate-smart and can tolerate warm climates and droughts.
    • Millets are photo-insensitive as they don’t require specific photoperiod for flowering.
    • Millets are thermophilic as they can thrive in high temperatures and xerophilic (i.e. can survive in limited water)
  • Millets have less water requirement as compared to other crops due to an efficient root system
  • Millets are less affected by diseases and pests.
  • Carbon Sequestration: Millets are C4 Carbon Sequestration crops contributing to the reduction of CO2 in the atmosphere.

2. Nutrition

  • Millets are rich in vitamins, calcium, iron, potassium, magnesium, and zinc, which can reduce the malnourishment and hunger problem in India.
  • Millets have a low glycaemic index. They are beneficial to highly diabetic people.  
  • Millets are gluten-free. Hence, they are beneficial to gluten-intolerant people.

3. Positive Externality

  • Millets have an excellent ability to sequester carbon and assist in climate adaptation.  
  • It can get proper nutrients from Organic Fertilisers. Chemical fertilizers are not required.

4. Productivity

  • Millets have a short growing period of 65 days. It allows multiple cropping, thus helping farmers to increase their incomes.

5. Cultural Aspect

  • Millets are traditionally associated with the cultivation practice of tribals, e.g. Karnataka Ragi Habba (Festival).
  • Millets have a long history in the Indian subcontinent, and their reference can be found in poetry, ayurvedic recipes etc. Hence, millets are interwoven into the socio-cultural fabric of numerous regions of India.

6. Export Potential

  • Millet has great export potential as millet is the staple food in most of Africa. From 2013-18, India exported 15.4% of the world’s Bajra.

7. More from Less

  • Millets do not require
    • High mechanization
    • Fertilizers 
    • Large supply of water
    • Pesticides and insecticides
  • Hence, it can increase the real income of farmers because input cost is low. 

Challenges

  • Unfavourable agricultural Policy: Crop loans, subsidies, and Public Distribution System (PDS) are favourable for crops such as Rice, Wheat etc. which acts as a disincentive towards cultivating Millet.
  • Dietary Habits– Due to increasing urbanization and industrialization, people are converging towards consuming Rice and Wheat (India Council of Agricultural Research 2014.) 
  • Lack of Awareness about the socioeconomic and nutritional benefits of Millet distorts its demand and supply. Moreover, Millets have a ‘poor man’s food’ tag, further reducing their consumption. 

Efforts to promote Millets

  1. 2018 was declared the National Year of Millets.
  2. Millets are part of the National Food Security Mission (NFSM).
  3. Millets are included under Poshan Abhiyan 2.0 and Saksham Anganwadi.
  4. India has more than 500 StartUps which are involved in Millet Value Chain. Indian Institute of Millet Research is incubating 250 Millet StartUps under Rashtriya Krishi Vikas Yojana-RAFTAAR. 
  5. FAO celebrated 2023 as the ‘UN International Year of Millets‘.

Pulses

  • India is world’s top producer & consumer of pulses. But even after that, India is not self-sufficient in the case of Pulses.
Pulses production in India
  • Major pulses that are grown in India: are tur, urad, moong, masur, peas and gram.
  • Pulses can be grown in all parts of the country except the heavy rainfall areas. 

The share of different pulses in total pulse production 

Pulse Share Major producers
Gram / Chana 45% Madhya Pradesh, Rajasthan and Maharashtra
Tur / Arhar 15% Maharashtra, Karnataka and Madhya Pradesh
Urad 10% UP, Andhra Pradesh and Maharashtra
Moong 10% Rajasthan, Maharashtra and Andhra Pradesh
Masur 5% UP, Madhya Pradesh and Bihar
Others 15%  

The area under pulses has decreased in the country. The main reason is the area under pulses is being shifted to the more profitable crops like rice and wheat after the green revolution.

Importance of Pulses

  • Pulses are rich in vegetable protein. Since most Indians are vegetarians. Hence, pulses are the primary source of protein for a majority of people
  • Pulses are leguminous crops which can fix atmospheric nitrogen in the soil and hence are usually rotated with other crops.

Government Initiatives to promote Pulse Production

  1. National Food Security Mission (NFSM)-Pulses: Aims to Increase Pulses production by 3 Million tonnes 
  2. Increase in MSP of Pulses 
  3. Price Support Scheme (PSS) under PM-AASHA 
  4. Creation of Buffer Stock of Pulses by NAFED. 
  5. Price Stabilization Fund Scheme to check volatility in the prices. 

Aviation

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Last Update: Feb 2025 (Aviation)

Aviation

This article deals with ‘Aviation – UPSC.’ This is part of our series on ‘Economics’ which is an important pillar of the GS-3 syllabus. For more articles, you can click here.

Introduction

  • India’s domestic passengers have almost doubled in the last 5 years owing to the UDAN scheme
  • In 2020, the number of airports in India reached the 100 mark.
  • India has become the 3rd largest domestic aviation market in the world (after USA and China).
  • Aviation sector generates 70 lakh jobs and $35 billion in India’s GDP.

Potential of Civil Aviation Sector

  • The geographical, economic and demographic conditions are such that India can be on the third-largest number of airline passengers. These favourable conditions are listed below.
    • India’s geographical location in the middle of the Eastern and Western Hemisphere
    • India has a robust middle class of about 35 cr Indians. 
    • Rising income due to India being one of the fastest-growing economies globally
    • High tourism potential
  • But strict and outdated regulations have not allowed the sector to achieve its potential.

Aviation Challenges

Aviation

1. Infrastructure Constraints

  • The civil aviation infrastructure, especially in the metros such as Delhi, Mumbai etc., has been operating at saturated levels. Therefore, the government will have to attract large investments in building new and upgrading the existing infrastructure.

2. Aviation Turbine Fuel (ATF)

  • The taxation on Aviation Turbine Fuel (ATF) in India is high. Hence, ATF is priced 60% higher in India compared to the global average. Given the fact that ATF accounts for 40% of the operating costs of airlines, it puts Indian airlines under considerable pressure.

3. Lack of Skilled Workers

  • Given the growth of the aviation sector, India will need 0.25 skilled workers in the aviation sector over the next decade.

4. Limited Capacity of Airlines

  • 90% of traffic is concentrated in the metro cities. Although the potential consumer base is large, airlines have not been able to tap it.

5. Predatory Pricing

  • Indian airlines indulge in Predatory pricing, i.e. sell their tickets at very low prices to bleed the competitors out of business. But in the process, they bleed themselves and make substantial losses.

6. Aviation Safety

  • In India, there were 440 aviation safety violations in 2016 and 340 in 2017, which are quite high compared to global standards.

7. Other Challenges

  • High Airport Charges
  • High aircraft to man ratio

Airlines in India

Public SectorNo Public Sector Airline after Privatization of Indian Airlines
Private Sector – Air India = owned by Tata GroupB
– Jet Airways = Naresh Goyal
– Spicejet = Sun group (of Kalanidhi Maran)
– Interglobe Aviation (IndiGo)
– Go Airlines
Cargo Airlines – Deccan Cargo (Deccan 360) 
– Blue Aviation
– Express Logistics

New players in the Indian market

  • Air Asia (Tata 30%+ Malaysian Airline AirAsia 49% + Telstra 21%)
  • Akasa Airlines (started in 2023 and founded by Rakesh Jhunjhunwala)
  • Quickjet Cargo Airlines

Air India

  • Air India was formed after Air India & Indian Airlines merger in 2007. 
  • It has the largest fleet in India, including new planes. It controls 17% of the Indian Market.
  • But it suffered from a debt of over ₹50,000 Crore. Hence, the government wanted to privatize it. After large discussions, the Tata group has bought the airlines. 
  • In 2025, Air India has rolled out free Wi-Fi internet services on its domestic and international flights on select aircrafts.

Pawan Hans Helicopter ltd

  • It is a government-owned company started in 1985. 
  • Provides helicopter service to
    • ONGC’s offshore drilling platforms
    • Hilly and inaccessible areas
    • Amarnath Yatra
    • Emergency evacuation

Disinvestment of Air India

Timeline of Air India

1932 Tata Airlines begins offering air services in India
1946 Tata Airlines renamed as Air India (AI)
1953 Air Corporation Act passed, and Air India was nationalized along with 7 other private carriers.
1981 Vayudoot, a new carrier, established to act as a regional feeder airline
1986 To boost tourism, private air taxis were allowed to fly with riders.
1993 After suffering an annual loss of ₹200 crores, Vayudoot was merged with Indian Airlines, adding to its debt load.
1994 The Air Corporation Act was repealed, and private carriers were allowed to enter the market again.
2003 Naresh Chandra Committee report calls for the privatization of Indian Airlines and Air India but faces stiff opposition.
2005 Air India signs a purchase agreement for 50 Boeing aircrafts at the cost of ₹ 33,000 crores.
2007 Indian Airlines & Air India were merged to form the National Aviation Company of India Ltd.
2010 The company was renamed Air India
2011 CAG hauls up Air India and Civil Aviation Ministry for reckless purchase of aircrafts
2017 Air India losses mounted to ₹ 50,000 crores forcing the government to move towards privatization.
2021 Tata group bought Indian Airlines from the Government of India.

Debt Causes

Air India had a debt of ₹ 50,000 crores, accumulated for various reasons spanning decades. CAG Report of 2011 too has given detailed reasons for this 

  1. Unprofessionalism in management when compared to world-class airlines. 
  2. Massive fleet expansion 
  3. Free travels by VVIPs like Ministers and Officials
  4. In early 2005, Indian Airlines inducted planes despite no demand for them. These were funded by raising high-interest loans.  
  5. Liberalized policy on international routes like nonstop flights to the US was loss-making.

Pros of disinvestment of Air India

  • Indian Airlines is loss-making. Hence, keeping it afloat under government control would be wasting taxpayers’ money.  
  • The private sector has taken up, and private airlines already cater to over 85% of the air travel demand in the country.
  • It would bring professionalism in management.  
  • Government money that keeps Air India afloat would be better used to fund important social and infrastructure programs. 
  • It will help the government to spend its energy on core governance issues. 
  • The sale of Pawan Hans in 2016 revived the company owing to the infusion of professionalism and better management.

Cons of disinvestment of Air India

  • Many sectors and routes that private airlines may not find economical to operate are handled by Air India. E.g., Private Airlines give limited services to North East. 
  • Air India, which is a sovereign airline, is used by Government in emergency evacuations of Indian nationals from warzones.  

National Civil Aviation Policy, 2016

Key highlights of  Aviation Policy-2016 are as follows

1. 5/20 rule Scrapped

  • 5/20 rule, i.e. the requirement of 5 years of operation and a fleet of 20 aircraft before handling international flights, has been scrapped. 
  • But airlines will have to operate at least 20 aeroplanes or 20% of their planes (whichever is higher) on domestic routes. 

2. Improve Air connectivity to smaller cities 

  • The policy wants to improve air connectivity with smaller cities. 

3. Subsidized Tickets

  • Under the regional connectivity scheme, the maximum price that can be charged is Rs 2500 per hour.
  • A 2% levy is to be charged on all domestic and overseas tickets to subsidize airlines’ losses.

4. Infrastructure

  • Airports in Tier 2 and 3 cities will be operationalized on the ‘No Frills Model’. 

5. Open Skies Policy

  • Under the ‘Open Skies Policy’, foreign airlines can operate unrestricted and unlimited flights in and out of India. It will help India become a regional hub like Dubai and Hong Kong. 

6. Other important

  • Maintenance, Repair & Overhaul (MRO) don’t have to pay a royalty to airports where they operate, which will help make India an MRO hub. Royalty is up to 20% presently.  

Side Topic: No Frills Airport

  • No Frill Airports are the airports with lesser facilities like no escalators, no AC Lounges etc.
  • These Airports are made in small cities because airports providing high-end facilities are not feasible in Tier II & III Cities.
No Frills Airport

UDAN Scheme

Timeline

2017 Aviation Ministry announced a scheme named UDAN (Ude Desh ka Aam Naagrik) to increase air traffic to Tier II & Tier III cities. 
2018 Second phase of UDAN scheme announced.
2019 UDAN (International) scheme launched, under which Guwahati Airport will be connected to Bangkok and Dhaka shortly. 

Under Scheme

  • Capping the fare
    1. Airfare for an hour’s journey of about 500km is capped at ₹2,500. 
    2. In the case of helicopter operations, fares are capped at ₹2,500 for a 30-minute flight.
    3. Seaplanes have also been included in the scheme in the subsequent phases. 
  • Capping of airfare is applicable on half of the flight’s seats.
  • Centre provides subsidy support to airlines via a Viability Gap Fund (VGF), which obtains money by levying cess on non-regional routes. 
  • Airlines get three-year exclusive rights to operate regional flights. 
  • No airport charges for airlines as airline operators complain that airport expenses constitute 25% to 30% of operating costs.
  • The scheme will be operational for a period of 10 years. 

Importance

  • The scheme has brought Tier 2 and Tier 3 cities into the country’s aviation network. 
  • Positive Spillover Effect on Economy: The scheme will make businesses and trade more efficient, enable medical services and promote tourism.
  • Employment Generation: As per the International Civil Aviation Organisation, each job created in the aviation sector creates 6.1 jobs in the economy. 
  • This scheme can help in improving the health of the ailing Aviation Sector. Even if 1 middle-class family buy 1 air trip per year, the Aviation sector can sell 35 crore tickets. 

Issues

  • Misdirection of Subsidy 
    • Even without the subsidy, there was an increase in air flyers.  
    • The subsidy is given to Middle Class when it could better serve some Social Schemes aimed at Lower Class.
  • Against Laisse – Faire: Airlines are given exclusive rights for 3 years, and other airlines cant operate there even if they want to. 
  • Another levy for creating the Viability Gap Fund will impact the already overtaxed Aviation Sector. Taxes on ATF is already among the highest in the world.

NABH (Nextgen Airports for Bharat) Nirman initiative

Aim: Capacity augmentation of the airports because 25 busiest airports of India are operating beyond their capacity.  

What it will do?

  • Expansion of the airport capacity to handle a billion trips a year.  
  • Establish about 100 new airports in the next 15 years at an estimated Rs 4 lakh crore investment. 
  • Increase the economic and tourism activities in the smaller cities by connecting them with airline services.

Side Topic: Wi-Fi Internet Services in Airplane

  • In 2025, Air India rolled out free Wi-Fi internet services on its domestic and international flights on select aircraft.
  • Two technologies can be used, i.e. Air-to-Ground (ATG) technology, which relies on ground-based cellular towers,  and Satellite-based connectivity. Signals in both technologies are received by the special antennae installed on the aircraft, which are  then provided to the passengers using Wi-Fi routers.

FDI in Aviation

FDI in Aviation

Bodies related to Aviation Sector

Ministry of Civil Aviation

  • Ministry of Civil Aviation mainly looks after the Aviation sector in India 

Airport Authority of India

  • AAI is a PSU of Miniratna category. 
  • Sovereign Air traffic controller of India.
  • It manages international airports, domestic airports, and custom airports.

Directorate General of Civil Aviation (DGCA)

  • DGCA is the regulatory body of Civil Aviation. 
  • Its functions include 
    • Registrar of civil aircrafts
    • Laying down airworthiness requirement 
    • Gives license to pilots
    • Investigation of minor accidents 
    • Implements Chicago Convention

Bureau of Civil Aviation Security (BCAS)

  • Initially, it was a cell in DGCA setup in 1976 on the recommendation of the Pandey Committee after an aircraft hijack in 1976. It has been restructured now an independent department under the Ministry of civil aviation, after Kanishka Tragedy in 1985
  • BCAS is the regulator of the security of civil aviation. 
  • Under Aircraft Security Rules, 2022, BCAS can impose penalties of up to ₹1 crore on airports and airlines for violation of security measures. 

International Civil Aviation Organization (ICAO)

  • ICAO is a specialized agency of the UN and was set up under the provisions of the Chicago Convention of 1944.
  • It is headquartered in Montreal, Canada and India is a member of ICAO since its inception.
  • ICAO ensures the operation of airlines between different countries.

Railways

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Last Update: Feb 2025 (Railways)

Railways

This article deals with ‘Railways – UPSC.’ This is part of our series on ‘Economics’ which is an important pillar of the GS-3 syllabus. For more articles, you can click here.

General Information

Timeline

1853 First Train started in India (from  Mumbai to Thane (34kms))
1924-25 Rail budget was separated from general budget (based on the Acworth Committee Report of 1921)
2015 Bibek Debroy Committee on railway restructuring gave recommendations.
2016 India’s first Railway University opened in Vadodara, Gujarat
2017 Railway Budget was merged with General Budget.

Share of Railways in the transportation of goods

In the US, 44% of goods are transported through railways, but in India share has been decreasing each passing year  (65% in 1970, 30% in 2007 & 25% in 2020)

Railways

Benefit of Railways wrt other modes of transport

  • Cheaper: The transportation cost of goods using railways is low (₹2/ton/km).
  • Low Carbon Footprint: Railways are a greener mode of transportation as they consume 20% less energy.
  • Integrate India with world markets: Railways can help to expand & integrate markets as they did in Europe and the USA. 
  • Spur economic activity: According to Economic Survey, 1 rupee invested in the railways increases GDP output by 5 rupees.

Railway gauge size

Gauge Size
Broad – 1,676 mm
– British used it to send raw material from Indian hinterland to port cities
Meter 1,000 mm 
Narrow 762 mm
Lift  610mm
  • Ranking track length in India: broad > meter > narrow
  • Under the Project uni-gauge, Railways has converted selected routes into broad gauge.

Railway Undertakings

Indian Railway has 14 undertakings. Important ones are 

  • IRCTC (provides catering services)
  • CONCOR (Container Corporation of India)
  • Railtel

Railway Zones

  • Indian Railway has 18 zones.
  • 18th Zone i.e. South Coast Railway Zone was created in 2025.
  • Zones Include
Northern Railways 1. Northern: New Delhi
2. North Western: Jaipur
3. North Central: Prayagraj
4. North Eastern: Gorakhpur
5. North East Frontier: Guwahati
Western Railways6. Western: Mumbai
7. West Central: Jabalpur
Central Railways8. Central: Mumbai
Eastern Railways9. Eastern: Kolkata
10. East Central: Hajipur
11. East Coast: Bhubaneshwar
12. Kolkata Metro: Kolkata
Southern Railways13. Southern: Chennai
14. South Western: Hubali
15. South Central: Secundrabad
16. South Coastal: Visakhapatnam
17. South East Central: Bilaspur
18. South Eastern: Kolkata

Statistics about Indian Railways

Statistics about Indian Railways
Operational Ratio of Indian Railways

UNESCO World Heritage: Indian railways

  1. Darjeeling Himalayan Railways
  2. Nilgiri Mountain Railways
  3. Kalka Simla Railway
  4. Chhatrapati Shivaji Terminus (Victoria Terminus) (It was designed by British architect FW Stevens in  Gothic Style)

National Rail Plan for India, 2030

Under this plan, the government of India wants to achieve the following

  1. Increase Indian railway’s share in freight transportation to 45% and average speed of freight transportation to 50% by 2030.
  2. Achieve 100% electrification of all train routes.
  3. Increase the speed of Delhi-Howrah and Delhi-Mumbai routes to 160 km/hr.
  4. Identify and develop new Dedicated Freight Corridors and High-Speed Rail Corridors.
  5. Improve the safety of railway tracks in India.

Railway Budget merged with General Budget

Railway Budget vs General Budget

  • 1924-25: British separated rail budget based on the recommendations of Acworth Committee (1921).
  • Indian constitution didn’t provide for a separate railway budget or budget in parts. But Parliamentary rules of procedure permitted it.
  • 2017: Railway Budget was merged with General Budget.

Arguments for merging Railway Budget with General Budget

  1. Economic Reasons:
    • Saving funds of financially starved Railways: Indian Railways need not pay the annual dividend of ₹10,000 crores to the Government. 
    • Railways will be better equipped to raise funds on the strength of the sovereign instead of being restricted to the Indian Railway Finance Corporation.
  2. The situation is different from 1924:  In 1924, the railway’s expenditure was more than the expenditure of all other administrative expenses. It has presently reduced to just 6% of total government spending.
  3. Any other country does not follow this system. 
  4. Politicization of Railways: This provision was used by politicians for populist reasons.   
  5. Bibek Debroy Committee too has suggested separating the railway budget from the general budget.

Why should there be a separate budget for the Railways?

  1. Indian Railways is different from other central ministries due to its size and scope. Whereas other ministries just spend, Railways is an operational ministry as it earns and spends. 
  2. Bibek Debroy Committee has recommended separating the railway budget from the general budget. But it wasn’t a standalone measure.

Metros / Mass Rapid Transit System (MRTS)

  • Rapid transit, also known as the metro or subway, is high-capacity public transport. Unlike buses & trams, they are electric & operate on an exclusive right-of-way. 
  • First Metros was started in Kolkata in 1984 from Dum Dum to Tollygunge. 

Benefits

  1. Reduced traffic density on the roads
  2. Reduced vehicular emission leading to decreased air pollution
  3. Reduced fatalities due to road accidents
  4. Reliable & safer journey
  5. Decreased fuel consumption
  6. Decreased vehicular operating cost

Metro Rail Policy, 2017

Metro Rail Policy, 2017

Indian Government has announced its Metro Rail Policy with PPP as the centre of the scheme. 

  • PPP is the centre of the scheme. The PPP component has been made mandatory for availing assistance from the central government.
  • The new policy mandates Transit Oriented Development (TOD).
  • Power to set up Fare Fixation Authorities has been vested with states. 
  • States can raise low-cost debt capital through the issuance of corporate bonds. 
  • Empowers state to charge a “betterment levy” in areas that will benefit from the metro rail projects. 

Problem with the Policy

  • The main problem is with the PPP model. PPP model has failed in Delhi Metro’s airport line — and is faltering in the Mumbai and Hyderabad metro rail projects. Due to various positive externalities of Metro, these projects must be subsidized by the government. In  Delhi Metro, the Centre and state government have footed much of the bills. Even E Sreedharan has opined that the PPP model is not suitable for Metros as private players expect more than 12% return from metro projects while no metro project can yield more than 3 per cent.

MetroLite or MetroNeo

  • MetroLite or MetroNeo is the model for Metros in smaller cities such as Nashville in the USA and Indian cities of Jammu, Coimbatore, Srinagar etc.
  • It was announced in the budget of 2021. 
  • These are a lighter version of conventional metro rail and can be set up at a lesser cost (2/3rd to 1/3rd cost of the normal metro).

Issues that Indian Railways is facing

1. Cross Subsidisation

  • Railways keep passenger tickets low –> Indian Railways suffer the loss of 23 paisa/passenger/km.
  • To compensate for the loss, Indian Railways keep freight prices higher.

2. Operating ratio of Indian Railways

  • The Operating Ratio of Indian Railways is just 98.4%, i.e. Indian Railways spend 98.4 rupees out of 100 rupees earned. Hence, only 1.6 rupees are left in surplus. 
  • It is a problem because Indian Railways left with no capital for expansion. 

3. Rail Safety / Large accidents

  • A large number of rail accidents such as derailments and collisions take place in India.

4. Congestion of Tracks

  • Indian railways has an overstretched  infrastructure  with 60 per cent plus routes being more than 100 per cent utilized,  leading to a reduction in the average speed of passenger and freight trains

5. Organisational Structure

  • Due to complex and outdated organizational structure, project approval and completion take extraordinarily long.

6. Other

  • Delay in execution of new projects.
  • Aging infrastructure (rail tracks and coaches)
  • Poor terminal facilities

Steps already taken to improve Railways

  • Tariff rationalization of fares has already been completed.
  • Indian Railways is focussing on Non-Tariff Earnings such as advertisement revenue.
  • Rail Budget has been merged with General Budget. 
  • Amrit Bharat Station Scheme has been started to enhance station amenities.
  • One Station One Product Scheme provides sale opportunity to the local artisans.
  • The government has constituted the Rail Development Authority (RDA).
  • New delivery models like Roll-on Roll-off (Ro-Ro) services have been started.
  • Adarsh Station Scheme has been started to develop railway stations.
  • 100% FDI is allowed in the Railway sector.
  • Indian Railways have changed the accounting system  to Accrual Based Accounting from Cash Based Accounting 
  • Indian Railway Finance Corporation has issued Masala Bonds to gather funds.
  • Kayakalap Council under the Chairmanship of Ratan Tata has been constituted

Side Topic: Accrual Based Accounting

Accrual Based Revenues are reported on Income Statement when they are earned
Cash Based Revenues are reported on Income Statement when they are received

Non-Tariff Earning

  • Indian Railways has decided to increase its focus on non-tariff earning
  • All the budgets since 2016 have emphasized on non-tariff earnings, and Indian Railways unveiled its first non-fare revenue policy in 2017.
  • Indian railways earn a minuscule amount from non-tariff revenue compared to their counterparts in other countries. E.g., Indian railways earn 5% of all its earnings from non-tariff revenue compared with 25-30% in Japan. 

How

  • Selling spaces on railway stations and railway containers for advertising hoardings and billboards.  
  • Leasing out spaces at platforms to ATMs. 
  • Selling branding rights of trains and stations. 
  • Leasing the land around tracks for horticulture purposes

Bibek Debroy Committee  on Railway Restructuring

Bibek Debroy is a noted economist & member of NITI AYOG. The committee was formed under Bibek Debroy to suggest measures to restructure railways. 

Suggestions of Committee

Bibek Debroy Committee on Railway Restructuring

The committee does not recommend the privatization of Indian Railways. However, it does endorse private entry with the provision of an independent regulator.

1. Reform in Human Resource Management

  • There are 8 services in Railways with different cadres, thus reducing the administrative efficacy. 
  • Recommendations: Unify the Cadre System for optimal utilization of human resources.  

2. Outsourcing

  • Outsource non-core areas, i.e. Police force, schools, hospitals, water bottling, museums etc. 

3. Regulator

  • The Committee has recommended that the Independent RAILWAY Regulator. 
  • Railway Board should continue only as an entity for the management of Indian Railways (PSU).
  • 2018 Update: Rail Development Authority has been constituted with the following functions
    1. Recommend tariff “commensurate with costs.” 
    2. Benchmark service standards
    3. Frame guidelines for track access charges on dedicated freight corridors.

4. Towards entry of private players

  • It recommended separating railway track construction, train operations, and rolling-stock production units under different entities to enable open access to private operators. 

5. Other Recommendations

  • Merge rail budget with General Budget.

Sanjeev Sanyal Committee Report (2021)

The main recommendations of the Committee include

  1. Wind up organizations such as Central Organisation for Railway Electrification (CORE), Centre for Railway Information System (CRIS) etc.
  2. Merge Rail Vikas Nigam into IRCON, Railtel into IRCTC and takeover of Braithwaite and Co. Limited by RITES as their functions overlap.
  3. Outsource the non-core functions. 

Private Train Operators

On selected routes, Private train operators will Design, Build, Finance and Operate (DBFO Model) their own private trains on government tracks  & charge market-linked fares. . Government (Indian Railways) will provide track and signalling infrastructure to them in return for which Private train operator will share a percentage of its revenue with Government.

Timeline of Rail Privatization

2011 Sam Pitroda Committee Attract private investment in building railway infrastructure. 2015 Bibek Debroy Committee Allow entry of private railway operators in goods and freight services 2021 Bharat Gaurav Policy Allowed Private Operators to run trains on theme based circuits

Benefits of Rail Privatization

  • It will lead to improved efficiency as private players will bring superior management, technology and amenities.
  • It will lead to a lack of political interference in the railway operations, and decisions will be taken on sound economic principles.
  • Increased competition: The entry of private players will ensure improved quality of service with competitive fares. 
  • Prevent Government’s loss: The revenue generated by the Indian Railways is low and keeps the system always at losses. 
  • Reducing the supply-demand deficit: Since waitlisted passengers comprise ~15% of the reserved passengers. 
  • Private investment: According to estimates, railway infrastructure needs an investment of ₹50 trillion between 2018 and 2030. Given the FRBM restrictions, involvement of private capital is required.  
  • Economic Growth: Private investment in the railways will also lead to economic growth due to its positive spillover effects.

Challenges with Rail Privatization

  • Private monopoly: Privatization in railways might create a private monopoly that might seek to set higher prices and exploit consumers.  
  • Coverage Limited to Lucrative Sectors: With privatization, less popular routes could be eliminated, thus hurting connectivity and rendering some parts of the country virtually inaccessible.  
  • Apprehension among railway employees about job-loss, if Government reduces the number of Government trains.
  • Fragmentation in the railways: Rail privatization broke unified railway operations into infrastructure management and train operating companies in the UK. It led to the absence of clear demarcation of responsibility.

Bharat Gaurav Trains and Bharat Gaurav Policy

  • Bharat Gaurav Trains are private trains that will operate on theme-based circuits (e.g., Ramayana Express connecting places associated with Lord Ram).
  • The operator can lease the train and coaches from the Indian railways and change the interiors provided they comply with the safety norms.
  • The tenure of arrangement can vary from a minimum of two years to the life of the coach. 
  • The operator can also decide the halts, sell advertisement rights etc.

Railway Safety

Main categories of Railway Accidents

  • Derailment of Trains is the primary cause of railway accidents, constituting 50% of railway accidents.
  • Accident on unmanned level crossing gates (36%)
  • Train collisions
  • Rail Fire 
  • Persons standing on railway tracks (e.g., In 2018, 61 people were crushed to death in Amritsar).
  • Natural Causes such as floods, landslides etc. 

Between 2012-2018, a total of 600 rail accidents happened.

Reasons for Railway Accidents

  1. Lack of anti-collision technologies that automatically halts the train if it overshoots a red signal.  
  2. Inappropriate maintenance of tracks: Khanna Committee on Railways Safety commented that nearly 25% of the total railway track in India is overaged.  
  3. Poor Rolling stock: Most trains’ locomotives are not equipped with the Linke Hoffman Busch (LHB) coaches. LHB coaches are more secure than ICF due to the lower centre of mass, preventing it from toppling, turtling, and telescoping.
  4. Rail Fractures: Railway Tracks are made up of strong and durable steel, which can withstand extreme weight and fluctuations in temperature. But Railway fractures do occur due to many reasons like defects during manufacturing, defects during installation and lack of maintenance. These Rail fractures are also among the frequent reasons for derailments.
  5. Government Negligence: Government has formed committees such as Sam Pitroda Committee, Khanna Committee and Bibek Debroy Committee. But all these reports kept on lying dormant and recommendations un-implemented.  

Steps taken by Government

  • Rashtriya Rail Sanraksha Kosh was created with a corpus of 1 lakh crores to promote railway safety.   
  • TCAS (Train Collision Avoidance System): TCAS is based on a combination of railway signalling data, global position, radio frequency identification devices (RFID), software and logic. 
  • Tri-Netra System: Tri-Netra or Three Eyes system is made up of (1) Optical video camera, (2) Infrared video camera and (3) Radar-based terrain mapping system. It will help in avoiding collisions even during the fog.
Tri-Netra System
  • Changing to LHB: Indian Railways is replacing the ICF (Integral Coach Factory) coaches with German-made Linke Hofmann Busch (LHB) coaches. 
  • Setu Bharatam Project: Under the Setu-Bharatam project, unmanned railway crossings are eliminated. 
  • Elimination of Mechanical Signalling: Indian railways is replacing the mechanical signalling with Electric and Electronic Interlocking Systems.

Way Forward: An independent body like Railway Safety Authority should be constituted to set the standards for Rail Safety and find the reasons and persons responsible for it in case of an accident.

Dedicated Freight Corridors 

Dedicated Freight Corridors are railway corridors designed to rapidly and efficiently transport goods and commodities. They are characterized by high speed and high capacity. 

Freight operations on the Indian Railways are set to witness a paradigm shift with the completion of its two dedicated freight corridors.

Eastern & Western DFC

Eastern & Western Dedicated Freight corridor
  Eastern corridor Western corridor
Start Ludhiana in Punjab Dadri in Uttar Pradesh
Funded by World Bank JICA
End Dankuni in West Bengal Jawaharlal Nehru Port Trust near Mumbai
Length 1760 Km 1468 Km
StatusFully completed in Oct 2023Partially Completed

Why DFCs?

  1. Segregate Passenger and Freight Operations: It will segregate freight infrastructure passenger transport. It will remedy the issue faced by freight trains, i.e. unpredictable and low speeds of around 25 km per hour. These trains can run at the average speed of 50-60 kph on the Dedicated Freight Corridors, thus leading to faster transport of raw material & finished material from factories to ports and vice versa. 
  2. Ease Pressure on Existing Routes: DFCs will reduce the congestion on existing routes as existing routes are already saturated. 
  3. Allow Passenger Trains to run at Faster:  Indian railways run fast passenger trains, slow trains, goods trains all on the same track. Hence trains like Rajdhani, which can achieve speeds up to 130kmph, run at an average of 70kmph.  
  4.  Reduce Logistic cost: At present, the logistic cost is about 14% GDP which is 30-40% higher than global benchmarked logistics cost.
  5. Combating Inflation: According to study by New South Wales University published in Elsevier journal in 2024, commodity prices have reduced by 0.5% owing to Dedicated freight Corridors owing to lower logistic costs and travel times.
  6. Increase Railways Share in Freight: DFCs will help India in containing the railway’s falling share of goods traffic, which is 44% in the US and 47% in China compared to just 25% in India.
  7. Impetus to Industrial Activity: DFCs will facilitate fresh industrial activity along the corridors.
  8. Environmental Benefits: DFC will help reduce congestion on highways and lower greenhouse  emissions. Carbon emission reduction may help India to claim carbon credits.

Issues / Constraints

  • Issue of Land Acquisition: Due to route alignment, the railways have to acquire large swathes of private land that are already developed, making the construction of the corridor difficult.
  • Double stack vs single stack: The project has adopted different technical standards for WDFC and EDFC. WDFC would have moving dimensions made for double-stacked containers, and moving dimensions for EDFC are being made for single stack container operations. This makes the seamless movement of double-stack trains from WDFC to EDFC impossible.  
  • Not enough bidders: Given the conditions set by the Japanese government (which is giving soft loans) and which stipulates the involvement of a Japanese partner, the total number of bidders has been low for the Western corridor.

High-Speed Rails (HSR)

High-Speed Rail Corridor Plan (Diamond Quadrilateral)

  • Under the High-Speed Railway Corridors (HSR) plan, the Railways intend to run trains at the average speed of 200- 300 Kmph.
  • Ministry of Railways has selected the following six corridors
    1. Delhi-Chandigarh-Amritsar
    2. Pune-Mumbai-Ahmedabad
    3. Hyderabad-Dornakal-Vijaywada-Chennai
    4. Chennai-Bangalore-Coimbatore-Ernakulam
    5. Howrah-Haldia
    6. Delhi-Agra-Lucknow – Patna

Ahmedabad-Mumbai HSR

  • Work on the Ahmedabad-Mumbai line has already been started.
  • It’s details are as follows
Length 508 km
Time to travel 2 km (compared to 7 hours taken by fastest train now)
Top Speed 350 km / hr
Cost of project ₹ 1lakh 8 thousand CRORE
Technology Used Japanese Shinkansen (Bullet Train) Technology
Current Status47.17% completed as of October 2024
Ahmedabad-Mumbai HSR

Why should India go towards HSR ?

  • Globally, India’s railway network is the fourth largest. Hence, India should build High-Speed Railways to move forward on the learning curve.
  • It has a multiplier effect. 
    1. Improved specialization in construction technologies (as done by China)
    2. The emergence of large MNCs like Alston of France and Hitachi of Japan
  • The development of HSR will have benefits on real estate & facilitate balanced urbanization. For example, the Beijing-Tianjin HSR line helped the growth of Tianjin’s real estate & commercial industry.  
  • Although High-speed railways directly compete with economy class tickets of an airline but have the following benefits vis-a-vis road and airlines.
    1. These rail systems have 30% less land requirement in comparison to expressways. 
    2. Energy consumption is 1/3 less than private cars & 5 times less than aeroplanes.
  • HSR system is highly safe. No accident has been reported in the entire history of the Japanese High-Speed Rail.

New Trains

1. Vande Bharat

  • It was formerly known as Train -18.
  • It was made and designed by Integral Coach Factory (ICF) based in Chennai under the Make in India Initiative 
  • These are semi high-speed trains that run at a speed of 160 Kmph (fastest in India).
  • It is an Engineless train running on Electrical Multiple Unit (EMU) Technology.
  • The train has state of the art facilities like onboard WiFi, CCTVs, Rotating Chairs, disabled friendly, intelligent braking system etc. 
  • As of 2024, more than 100 Vande Bharat Trains are in operation.

2. Bharat Gaurav Trains

  • Bharat Gaurav Trains are theme-based trains launched in 2021.
  • E.g., Buddhist Circuit Tourist Train (to explore Buddhist places), North East Circuit Train (to explore North Eastern States) etc.

3. Gatiman Express

  • Gatiman Express is a semi-high speed train.
  • It runs on electricity.

4. Antyodaya Express

  • Antyodaya Express is a fully unreserved superfast train that runs on dense routes. 

5. Tejas Express

  • Tejas runs at 130 Kmph and provides advanced amenities such as WiFi services.

6. Uday Express

  • Uday is a double-decker train running on busy routes. 

Introduction to Drainage System

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Introduction to Drainage System

This article deals with ‘Introduction to Drainage System ’ This is part of our series on ‘Geography’ which is important pillar of GS-1 syllabus . For more articles , you can click here

Terminology

Channel A defined zone which has a certain depth in which there is continuous flow of water under normal conditions.
Drainage The flow of water in well defined channel is known as Drainage .  
Drainage System The network of channels which drains a region is known as Drainage System.  
Drainage Basin The drainage basin is the area drained by the river and it’s tributaries.  
Catchment / Catchment Area The river drains the water collected from a specific area. This area is known as the Catchment Area or Catchment .  
Water Divide / Watershed Watershed divides the one catchment area from other catchment area. It is also known as Water divide.  
River Regime The seasonal flow of water in a river is known as River regime. Hence, if the water availability is uniform around the year, it is known as Uniform River Regime. Whereas rivers where the water is seasonal, it is known as Non-uniform River Regime. Such seasonal rivers are also known as Ephemeral rivers.  
Inland Drainage Rivers which don’t reach the ocean . In desert or arid regions, such rivers lead to the formation of Salt Lakes or Playa Lakes .

Types of drainage pattern

Geometric system of streams in a region is determined by.

1. Slope 3. Hydraulic Variability.
2. Difference in rock resistance to erosion 4. Structural  control of Landscape.

1 . Antecedent or Inconsequent

  • Antecedent drainage pattern is one in which a  part of a river slope and the surrounding area gets uplifted but the river sticks to its original slope, cutting through the uplifted portion forming deep gorges
  • Eg : Those rivers which existed before upheaval of Himalayas like Indus, Satluj, Ganga, Brahmaputra, Arun, Tista etc. . These rivers originates in Tibet and cut across Himalayas forming deep gorges.

2. Consequent

  • Rivers which flow in direction of slope.
  • Most peninsular rivers like Godavari, Krishna, Cauvery etc.

3. Superimposed /Superinduced

  • In this, drainage pattern exhibits discordance with underlying rock because it originally developed on a cover of  rocks that has now disappeared .
  • The river has enough erosive power that it can cut through any kind of bedrock, maintaining its former drainage pattern.
  • Damodar, Subarnarekha, Chambal, Banas etc.

4. Dendritic

  • Drainage in which branches give appearance of tree .
  • Dendritic pattern develops in a terrain which has uniform lithology, and where faulting and jointing are insignificant.
  • Most rivers of Indo-Gangetic plain show Dendritic drainage pattern.
Introduction to Drainage System

5. Trellis

  • Rectangular pattern where two sets of structural control occur at right angle.
  • Eg : Drainage pattern of Singhbhum(Chotanagpur).
Trellis Drainage Pattern

6. Obsequent

  • In Obsequent drainage pattern, tributaries intend to flow upstream instead of downstream.
  • Eg : Arun river which is tributary of Kosi & Suru of Indus.

7. Rectangular

  • The main stream bends at right angles and the tributaries join at right angles creating rectangular patterns.
  • It differs from trellis as it is more irregular.
  • It is found in Vindhyan mountains.
Rectangular Drainage Pattern

8. Radial

  • Outflowing rivers , away from central point.
  • Radial pattern tends to develop on flanks of a dome or volcanic cone.
  • Rivers originating from Amarkantak hills , Chotanagpur Plateau & Mikir hills .
Radial Drainage Pattern

9. Annular

  • Subsequent stream flows curving prior to joining the consequent stream.
  • It is not very common . In India, it is found in Nilgiri hills of Tamil Nadu & Kerala.

10 . Parallel

  • Rivers flow parallel to each other. In this, rivers will not meet but keep on running parallel.
  • Small rivers originating in western ghats & discharging water in Arabian sea.

11. Deranged

  • Uncoordinated pattern of drainage, characteristic of a region recently vacated by ice sheet & has  not adjusted according to solid rocks underlying.
  • Eg : Drainage pattern found in glaciated valleys of Karakoram.
Deranged Drainage Pattern

Indian rivers

There are various ways to classify Indian Rivers.

1 . On basis of Discharge of Water

  • All Indian rivers discharge water either in Arabian Sea or Bay of Bengal.
  • Nearly 77%  of the drainage area consisting of the Ganga, the Brahmaputra, the Mahanadi, the Krishna, etc. is oriented towards the Bay of Bengal while 23% comprising the Indus, the Narmada, the Tapi, the Mahi and the Periyar systems discharge their waters in the Arabian Sea.
  • They are separated from each other through the Delhi ridge, the Aravallis and the Sahyadri.
  • It should be mentioned here that the over 90% of the water carried by the Indian rivers is drained into the Bay of Bengal; the rest is drained into the Arabian Sea or forms inland drainage.

2. On Basis of Size of Watershed

Major River Basins Catchment area of more than 20,000 sq. km 14
Medium River Basins 2,000 to 20,000 sq. km 44
Minor River Basins Less than 2,000 sq. km 55

Ranking (catchment area)

Ganga Mahanadi
Indus Narmada
Godavari Kaveri
Krishna Tapi
Brahmaputra Pennar

3. On Basis of Mode of Origin

  1. Northern/Himalayan Rivers
  2. Peninsular Rivers.
    • Although it has the problem of including  Chambal,  Betwa, Son, etc. which are much older in age and origin. than other rivers that have their origin in the Himalayas, it is the most accepted basis of classification.
Rivers Himalayan Rivers Indus Ganga Brahmaputra Peninsular Rivers Mahanadi Godavari Krishna Cauvery Narmada Tapti

This marks the end of our article on Introduction to Drainage System. For other articles on geography, CLICK HERE.

Plateaus

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Plateaus

This article deals with ‘Plateaus.’ This is part of our series on ‘Geography’ which is important pillar of GS-1 syllabus . For more articles , you can click here

Introduction

  • Plateau is an elevated tract of relatively flat land , limited on atleast one side by steep slope falling abruptly
  • Eg: Tibetan plateau.

Reasons for formation of Plateaus

There are many reasons for the formation of Plateaus

  • When two mountain ranges are forming, then landmass in between them rise too &  Plateaus are formed .
  • Deposition from lava – if lava is basaltic it will spread easily &  form flat elevated surface
  • Deposition from wind over long time => After compression & solidification of deposited material plateau will form.
  • When upland of any surface is eroded due to glaciers, plateau is formed.

Types of Plateaus

1 . Intermontane plateau

  • Intermontane plateaus are  highest, largest & most complex plateaus of world.
  • Intermontane plateaus are enclosed and surrounded by mountain ranges from different sides.

Examples include

a. Tibetan Plateau

  • Stretches 1000 km north to south &  2500 km east to west & average elevation is 4500m  => called Roof of the world .
  • Bounded by Kunlun Mountains in the north & Himalayas in the south. 
  • Many major rivers of Asia like Indus, Brahmaputra etc rise here & also holds constellation of salt & freshwater lakes .

b. Plateau of Bolivia

  • Lies largely  in Bolivia
  • It has average elevation of 1350 m.
  • Highland  was uplifted during tertiary period when the Andes were formed
  • Contrary to Tibetan Plateau, it is very dry and  has no exterior drainage

c. Plateau of Mexico

  • Plateau stands between the eastern and western Sierra Madre Mountains.
  • It has average elevation between 1800 meters to 2300 meters
  • Large  parts of this Plateau are very dry.

d. Colorado Plateau

  • Situated in USA between Cascade Range and Rocky Mountains
  • It is situated at elevation

e. Anatolia Plateau

  • Lies in Turkey between Taurus & Pontic Range
  • It’s elevation is cause of cool weather of Turkey 
Intermontane Plateaus

2. Piedmont or Border Plateau

  • These  Plateaus border mountain ranges and owe their present position to the same uplifts that raised the mountains. 
  • Examples include
    1. Piedmont Plateau on the border of Appalachian Mountains
    2. Patagonia Plateau in South America

3. Volcanic Plateau

  • Volcanoes form variety of plateaus. 
    • Larger : built by BASALTIC lava flow.
    • Small : formed by resistant lava caps that aren’t eroded & maintain its elevation after surrounding land has been worn away.
  • Examples are
    • Columbia Snake Plateau .
    • Deccan Plateau , India.
    • Shan Plateau , Myanmar
    • Katanga Plateau, Congo
    • North Island in New Zealand
Volcanic Plateaus of the world
Volcanic Plateaus of the world

4. Erosional Plateau

  • Form in semiarid regions where streams have cut away portions of high lands.
  • Examples include
    1. Allegany Plateau near  New York 
    2. Cumberland Plateau near Appalachians in USA

5. Depositional Plateau

  • Formed due to depositional action of wind
  • Examples include Loess Plateau in China => It is formed due to process of deposition of sediments carried from the desert  by the Anticyclonic  winds which develop over Russia and come to China shedding their load in this area
Loess Plateau

6. Dome Plateau

  • These plateaus are uplifted by folding and faulting processes  into a broad dome.
  • Entrenched Meanders are feature of these plateaus
  • Examples include Ozark Plateau of USA

7. Glacial Plateau

  • These are formed due to  erosional action of glaciers.
  • Examples include
    1. Laurentian Plateau of Canada (North America)
    2. Garhwal Plateau of India

Importance of Plateaus

  • Plateaus have large amount of   mineral wealth like Gold, Iron, Copper, Diamond, Manganese, Mica , Granite etc. which forms industrial base of any economy. Eg : Katanga Plateau of Congo is very rich in copper and Deccan Plateau of India is very rich in resources.
  • Plateaus are have more plain regions as compared to pure mountainous regions which helps in development of means of transport. Rail and road transport is lesser costly in plateau regions as compared to mountainous regions.
  • Plateau regions have abrupt slopes which are beneficial for setting up hydroelectrical centres thus helping in overall development of the region
  • Plateaus greatly effect the climate of region . For example Tibet plateau divides western Jet Stream in two parts while in summer and helps to create low pressure over Indian subcontinent which results into attraction for Monsoons 
  • They are important agriculturally as well . Eg : Deccan Plateau in India has black soil which is unmatchable for production of Cotton and Sugarcane.
  • Plateaus especially Intermontane Plateaus are great source of water resources as well. Eg: Large number of rivers like Indus , Brahmaputra etc originates from Tibet plateau.

Continental Drift and Plate Tectonic Theory

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Continental Drift and Plate Tectonic Theory

This article deals with ‘Continental Drift and Plate Tectonic Theory.’ This is part of our series on ‘Geography’ which is important pillar of GS-1 syllabus . For more articles , you can click here

Continental Drift Theory

  • Given by Alfred Wegener (German Meteorologist)  in  1912   . It speaks about rifting and drifting of continents .
  • According to Wegener, about 250 million years ago all the continents formed a single continental mass and mega ocean surrounded the same. 
    • Super continent was named PANGAEA, which meant all earth.
    • Mega-ocean was called PANTHALASSA, meaning all water.
  • He argued that, around 200 million years ago, the super continent, Pangaea, began to split. 
    • Pangaea broke to Laurasia/ Angaraland (forming Northern Continents) and Gondwanaland (Southern Continents) with Tethys Sea between them. 
    • Subsequently, Laurasia and Gondwanaland continued to break into various smaller continents that exist today. (Note – India was part of Gondwanaland.)
  • Interesting theory but was scrapped saying it GEO-POETRY because he wasn’t able to explain forces of movement.

Continental Drift theory was based on following clues

a. Continental fit / Jig Saw Fit

  • Continental lands can be joined together like jig saw puzzle.

b. Rocks of same age across oceans

  • Belt of ancient rocks of 2,000 million years from Brazil coast matches with  western Africa. 
  • Geological Structure of Appalachian Mountains matches with Morocco and Algeria in North Africa.

c. Fossils

Mesosaurus Freshwater reptile found in Africa & South America.
Glassopteris Fern found on all southern continents.
Lemur Found in India, Africa and Madagascar.

d. Placer Deposits

  • The occurrence of rich placer deposits of gold in the Ghana coast and the absolute absence of source rock in the region => gold bearing veins are in Brazil => Ghana & Brazil Plateau used to lay side by side.

e. Tillite

  • Tillite are the sedimentary rock formed out of deposits of glaciers.
  • Gondwana system of sediments from India has counter parts in six different landmasses of Southern Hemisphere.
Pr

Forces for Drifting

  • Wegener suggested that movement responsible for drifting of continents was caused by pole-fleeing force and tidal force.
  • Polar-fleeing force relates to the rotation of the earth.
  • Tidal force—is due to the attraction of the moon and the sun that develops tides in oceanic waters.
  • Wegener believed that these forces would become effective when applied over many million years. However, most of scholars considered these forces to be inadequate 

Post Drift Studies

  • It is interesting to note that for continental drift, most of the evidences were collected from the continental areas .
  • Number of discoveries during the post-war period added new information to geological literature. Particularly, the information collected from the ocean floor mapping provided new dimensions for the study of distribution of oceans and continents.

Convectional Current Theory

  • Wegener wasn’t able to explain the  force  behind Continental Drift.
  • Arthur Holmes in 1930s discussed the possibility of convection currents operating in the mantle portion. These currents are generated due to radioactive elements causing thermal differences in the mantle portion. Holmes argued that there exists a system of such currents in the entire mantle portion.
  • These convection currents are nothing but molten rocks
    • Rising limb :  it will pressurise crust in such a way that crust will break .
    • Diverging limbs :  take crust away from each other .
    • Descending limbs : make two crusts to collide (like Indian & Eurasian plate ).
  • According to Holmes , these Convection Currents are the Driving Force . This was an attempt to provide an explanation to the issue of force, on the basis of which contemporary scientists discarded the continental drift theory.
Convectional Current Theory

Ocean  Seafloor Spreading Theory

Post war studies using which Ocean Map was prepared showed that ocean floor is not just a vast plain but it is full of relief.

Mapping of the ocean floor and palaeo-magnetic studies of rocks from oceanic regions revealed the following facts :

  • It was realised that all along the mid-oceanic ridges, volcanic eruptions are common and they bring huge amounts of lava
  • Ocean crust rocks are much younger than the continental rocks. The age of rocks in the oceanic crust is nowhere more than 200 million years old. Some of the continental rock formations are as old as 3,200 million years.
  • Age  of the rocks increases as one moves away from  crest.
  • Sediments  on the ocean floor are unexpectedly very thin => nowhere was  sediment column found be older than 200 million years.
  • Deep trenches have deep earthquake occurrences while in mid-oceanic ridge areas, earthquake foci have shallow depths
  • Concept of zebra strip / Magnetostratigraphy : rocks equidistant on either sides of mid-oceanic ridges show  similar magnetic properties

This led Hess (1961) to propose his hypothesis, known as the “sea floor spreading”

  • Constant eruptions at  crest of oceanic ridges cause  rupture of the oceanic crust and  new lava wedges into it, pushing the oceanic crust on either side. The ocean floor, thus spreads.
  • Ocean floor that gets pushed due to volcanic eruptions at crest, sinks down at the oceanic trenches & gets consumed (Seafloor Spreading Theory).
Ocean Seafloor Spreading Theory

Plate Tectonic Theory

  • Given in 1967 by McKenzie & Parker
  • Tectonic plate ( lithospheric plate) is a massive slab of solid rock, generally composed of both continental and oceanic lithosphere. Plates move horizontally over the asthenosphere . Its thickness range varying between 5-100 km in oceanic parts and about 200 km in the continental areas.
  • A plate may be referred to as the continental plate or oceanic plate depending on which of the two occupy a larger portion 
    • Pacific plate is largely an oceanic plate
    • Eurasian plate may be called a continental plate.
  • Theory of plate tectonics proposes that the earth’s lithosphere is divided into seven major and some minor plates.
  • Young Fold Mountain ridges, trenches etc are formed due to movement and interaction of these plates

The major plates are

  • Antarctic and the surrounding oceanic plate
  • North American
  • South American
  • Pacific plate.
  • India-Australia-New Zealand plate .
  • Africa with the eastern Atlantic floor plate .
  • Eurasia and the adjacent oceanic plate.

Some important minor plates are

  • Cocos plate : Between Central America and Pacific plate .
  • Nazca plate :Between South America and Pacific plate .
  • Arabian plate : Mostly the Saudi Arabian landmass.
  • Philippine plate : Between the Asiatic and Pacific Plate .
  • Caroline plate : Between the Philippine and Indian plate (North of New Guinea) .
  • Fuji plate : North-east of Australia.
  • 2017 update – Zealandia is now considered separate Continent/Plate

These plates have been constantly moving over the globe throughout the history of the earth.

  • All the plates, without exception, have moved in the geological past, and shall continue to move in the future as well.
  • Pangaea of Wegner was also result of convergence of continental masses
Movement of Continents in history

Plate Boundaries

There are three types of plate boundaries according to Plate Tectonic Theory (these three types of plate boundaries are discussed in detail below)

Type of Boundaries

Rate of Plate Movement

  • Strips of normal and reverse magnetic field that parallel the mid-oceanic ridges help the scientists to determine the rates of plate movement.
  • These rates vary considerably.
    • Arctic Ridge: slowest rate (less than 2.5 cm/yr),
    • East Pacific Rise in the South Pacific : fastest rate (more than 15 cm/yr).

Force for the Plate Movement

  • Convectional Currents which were first explained by Hess in his Convectional Current Theory was the main force behind plate movement

Side Topic : Palaeomagnetism & how it prove Plate Tectonics

Palaeomagnetism is the study of the record of the Earth’s magnetic field in rocks and sediments

How it proves Plate Tectonic Theory

  • Magnetostratigraphy, with rocks equidistant on either sides of mid-oceanic ridges show  similar magnetic properties
  • Polar wandering – Magnetic minerals formed at same time but on different continents points have different orientation .  So, there were either multiple north poles during the same time period or that the continents moved in relation to a single north pole. Geophysicists concluded that the magnetic poles remained stationary, and the continents moved
  • Palaeomagnetism is also used to match once joined landmasses that are now separated. For example, the orientation of magnetic minerals along the eastern coast of South America very closely matches that of similar minerals on the western coast of Africa. 

Convergent Plate Boundaries

Convergent plate boundary is the margin where two plates collide with one another.

Convergent plate boundary

Convergent Plate Boundaries can be of three types :-

1 . Ocean Ocean Convergent Boundary

  • Denser of the two oceanic plates is subducted   . It goes to Asthenosphere & generate new Magma .
  • Andesitic Magma will from in this case . Andesitic Magma is less  mobile and solidifies quickly. As a result,  underwater Volcano or Volcanic island arc will form in this case.
  • Characterised by  Trenches , Underwater Volcanoes , Volcanic Island Arc and Earthquakes .
  • Island arc  (and not single island) will be formed because they will be formed on whole boundary where Ocean-Ocean plate is converging. All these islands will be volcanic islands .
Ocean Ocean Convergent Boundary

2. Ocean – Continental Convergence Boundary

  • Oceanic Plate is denser than Continental Plate . Hence, Ocean plate will be subducted into Asthenosphere &  melt down there. But at the same time, due to the great compressional force between two converging plates, folding will happen on the Continental Plate , resulting in formation of Marginal Fold Mountains . As we know, folding happens along the zones of  weakness , hence, when Magma of the subducted  Ocean plate will rise , it will  come out of the crust through these weak zones  resulting in formation of Volcanic Peaks .  
  • Hence, Volcanic mountains ranges, Trench and earthquakes  are common on boundaries
  • Examples of such volcanic mountain ranges are
Andes  mountains South America
Rockies North America
Atlas Africa
Ocean - Continental Convergence Boundary

3. Continental – Continental Convergent Boundary

  • When continental plate converges into continental plate , crust at  both sides is tool light  & buoyant to be subducted. Both are  compressed against each other and folding happens. Hence, in this case Fold mountain Belt forms.
  • No Volcanism but powerful earthquakes are created in this region .
  • Himalayas & Urals  are formed in this way due to convergence of Indo-Australian and Eurasian plates.
  • Pressure between plates is so high that metamorphic rocks form there.

Divergent plate Boundaries

  • Divergent plate boundary is the margin where two plates move apart. For instance, African plate and South American plate
  • Divergent plate boundary is termed as the constructive plate boundary as it leads to the formation of new lithosphere .
Divergent plate boundary

Divergent plate boundaries are of two types :-

1 . Ocean – Ocean Divergent Boundary

  • Creation of new crust takes place at submarine mountain ridge . Ocean crust is rifted apart & basaltic magma wells up to fill the opening.
  • Basaltic Magma will come out from the Mantle. Since basaltic magma  is very mobile, hence it will spread out. This magma hardens & forms igneous rock . Since magma is basaltic, hence ocean crust is basaltic in nature .
  • Mid-Atlantic Ridge is an ideal example of a submarine mountain ridge in the Atlantic Ocean. It is the longest mountain ridge in the world. It extends for about 16,000 km, in a ‘S’ shaped path, between Iceland in the north and Bouvet Island in the south
  • Water from hydrothermal vents (along the submarine ridges) is rich in dissolved minerals and supports organisms like chemo-autotrophic bacteria.

2 . Continental – Continental Divergent Plate

  • Rift  valley along with block mountains are formed when two continental  plates move apart.
  • Initially it leads to the development of a small body of water . But if rifting continues , body of water becomes bigger to juvenile ocean and consequently to Large Ocean.
  • Example : The Great Rift of Africa

Side Topic : Great Rift of Africa

  • In Great African Rift Valley, Continental Continental Divergence is observed leading to formation of Rift Valley.
  • Almost all the lakes in Africa are in the Rift Valley generated by diverging of  continental Plates except Lake Victoria.
Great Rift of Africa

Transform Plate Boundary

  • Where two plates are sliding past each other.
  • They are  under shear stress.
  • The lithosphere is neither destroyed nor created by the transform plate boundary. Hence , it is called Conservative or passive plate boundary.
  • Earthquakes are common & Volcanoes are not formed at Transform boundaries. Whenever plate boundary is active, Earthquakes are also experienced in that region.

  • Example –San Andreas Fault in USA (Pacific Plate & North American) , Chile etc
San Andreas FAult

Ocean Salinity

by

Ocean Salinity

This article deals with ‘Oceanography: Ocean Salinity’ This is part of our series on ‘Geography’ which is important pillar of GS-1 syllabus . For more articles , you can click here

Introduction

  • Salinity of Solution is defined as amount of salt in 1000 gram of water .
  • Salinity of ocean water is 35.5 ppt ( parts per thousand)  & maximum amount is of common salt.
Sodium chloride 78%
Magnesium Chloride 12%
Magnesium sulphate 3.5%
Calcium Sulphate 2.5%

Why Sodium Chloride (NaCl) is present in highest proportion ?

  • Every salt has cycle & they remain in sea water for specific time( called residual time) & then precipitated to bottom surface .
  • Sodium (Na) & Chlorine (Cl) has highest residual time in ocean water leading to very gradual removal => that is why they are present in highest proportion .

Salt Budget

  • Irrespective of absolute salinity,  proportion of above salts remain same in all parts of the world  .
  • Amount of addition or extraction of fresh water compared to salt content in ocean water decides absolute salinity of oceans .
  • Salt Budget  = Budget of addition of salt & removal of salt .

Sources of salts on ocean water.

  • Sediments carried by rivers (most important) .
  • Submarine volcanism at Mid Oceanic Ridge .
  • Chemical reaction between rocks of geothermal vent of volcano & cold water.
  • Erosion of oceanic rocks and wave erosion of coastal rocks  .

Removal of Salts in ocean water.

  • Physical Removal :  waves break at beaches ie salt spray .
  • Biological removal : marine life forms extract calcium from sea water for their bones & shells .

Factors effecting salinity

Evaporation Higher the rate of evaporation ,higher is salinity.
Temperature Warmer parts are more saline than frigid ones.
Precipitation Higher the precipitation, lower is the salinity.
Influx of Freshwater Influx of freshwater leads to lower salinity .
Atmospheric pressure  
Circulation of Ocean water Stagnant water has more salinity (Eg: Sargasso sea).
Windy situation Wind accelerate evaporation => windy situation = more saline

Salinity of Oceans

  • Standard  salinity of ocean water is 35.5 ppt ie salinity of Atlantic ocean .
Greater than 35.5 High saline.
Lower than 35.5 Less  saline.
  • Some highly saline lakes . Man  seldom drown in sea with high salinity because water is  highly dense .
Dead Sea 238 ppt West Asia
Lake Van 330 ppt Turkey
Great Salt Lake 220 ppt USA
Lake Urmia   Iran

Overall pattern of Salinity across world

Ocean Salinity

a. Latitudinal variation

  • Salinity is highest at tropics(not Equator)  & decreases on both sides.
  • This is due to Interplay of evaporation & precipitation & other complex interactions.

b. Hemispheric variation

  • Northern Hemisphere is warmer => high evaporation => more saline .
  • But southern Pacific => Roaring 40, furious 50 , Shreaking 60 , Screaming 70 => very fast winds . Hence in Pacific ocean , southern hemisphere has more salinity

c. Local Variation in Salinity

Warm ocean currents – Increases temperature of water => equivalent to High evaporation .
– Leads to more salinity.
Upwelling Cooler water from depth come to surface => low salinity.
Transport by currents The North Sea, in spite of its location in higher latitudes, records higher salinity due to more saline water brought by the North Atlantic Drift.

d. Enclosed Seas

Tropical region – Warmer than open sea .
– Will lead to high salinity.
– Eg Mediterranean Sea , Persian Gulf etc. 
High Latitude – Cooler than open sea .
– Lower salinity than open seas .
– Eg Baltic Sea, Gulf of Bothnia etc .

e. Inflow of large rivers

  • Ganga – Brahmaputra => flow into Bay of Bengal => large freshwater .
  • Bay of Bengal is less saline than Arabian Sea.

f. Glaciers

  • Those oceans /seas which receive greater glacier water are less saline
  • Baltic Sea is very less saline because of this reason .