Category Archives: Geography

How Asian desert dust enhances Indian summer monsoon

How Asian desert dust enhances Indian summer monsoon

Q. What is the news?

  • A recent study shows how dust coming from the deserts in the West, Central and East Asia plays an important role in the Indian Summer Monsoon.
  • The researchers also explain how the Indian Summer Monsoon has a reverse effect and can increase the winds in West Asia to produce yet more dust.

Q. What is Positive feedback loop?

  • Dust swarms from the desert when lifted by strong winds can absorb solar radiation and become hot. This can cause heating of the atmosphere, change the air pressure, wind circulation patterns, influence moisture transport and increase precipitation and rainfall. A strong monsoon can also transport air to West Asia and again pick up a lot of dust. The researchers say this is a positive feedback loop.

Q. How are aerosols transported?

  • Deserts across the globe play important roles in monsoons. The dust aerosols from deserts in West China such as the Taklamakan desert and the Gobi Desert can be transported eastward to eastern China and can influence the East Asia summer monsoon. And in the southwest United States, some small deserts that influence the North African monsoon.
  • Experts are divided on the issue of whether , Anthropogenic dust from vehicles, mining, construction can influence monsoons, some see      anthropogenic aerosols emitted from the Indian subcontinent can decrease summer monsoon precipitation, while others found that absorbing aerosols such as dust can strengthen the monsoon circulation. 

Q. What are the minor components?

  • The research team has planned to study the minor components of desert dust aerosols. Dust from deserts across the globe will have the same components, but since different deserts have different chemical compositions and this can influence the dust’s properties. For example, if one think that dust from the Middle East [West Asia] has more absorbing ability of solar radiation than dust from North Africa and this difference in absorbing ability might influence monsoon systems.
  • Researchers have also planned to use high spatial resolution remote sensing to identify source regions and create a better dust emission map. 
  • They would study new drying lakes and how dust from them can also play a role in the monsoons.

What could be the reasons behind an unusually large hole that has opened in the ozone layer over the Arctic?

What could be the reasons behind an unusually large hole that has opened in the ozone layer over the Arctic?

  1. Over the last month, a new hole in the ozone layer has started to form over the Arctic.
  2. The ozone layer over the North Pole has been depleted plenty of times in the past. But this time around, extreme weather and atmospheric conditions have led to a far greater depletion than normal
  3. This year’s Arctic ozone hole is bigger than normal because of atypically cold temperatures in the stratosphere that helped trap a whirlpool of icy wind, called a polar vortex, in the area that dispersed ozone more than usual.
  4. Still, even this unusually large hole in the ozone layer is considerably smaller than the more well-known hole over Antarctica.
  5. It remains unclear what to expect in the coming years. While the larger-than-average ozone hole was caused in part by extreme weather, which has been linked to climate change, it’s too soon to declare that the Arctic ozone depletion will continue to get worse if climate change continues unchecked.

Q. Discuss the mechanism of volcano formation and eruption. Also mention the distribution of volcano around the world.

Model Answer

Structure of the answer:

  • Meaning of volcano
  • Mechanism and causes for its formation
  • Distribution of volcano (with the help of data)
  • Conclusion

Volcanos or vulcanism comprises of all phenomena connected with movement of heated material from interior/mantle towards the earth surface. The volcano may be “active volcano” like Mount Etna or “dormant volcano” like Mount Vesuvius or Extinct volcano that have no indication of future eruption.

Volcanos are mainly associated with the weaker zones of the earth and is a result of several interconnected processes, such as:

  • Gradual increase of temperature with depth e.2-3 degree centigrade with every 100 meters.
  • Reduction in pressure on magma due to splitting of the plates.
  • Origin of gases and vapours due to heating of water (when it reaches underground surfaces of earth).
  • Ascent of magma under forces of gases and vapours.
  • “Theory of Plate tectonics” further lays down that volcanism is closely associated with plate boundaries. For ex.- When plate boundaries move in opposite direction like mid oceanic ridges causes splitting of plates and pressure releases. Similarly, destructive/ convergent plate boundaries are associated with explosive volcano.

Distribution of volcanos around the world: Generally, 80% of the volcanoes are located on the converging plate boundaries and 15% are located on constructive plate boundaries. On this basis there are three major belts of volcano—

  • Circum-pacific belt: along the east and west coast of Pacific Ocean. This area is also called Pacific Ring of Fire because of many earthquake and volcanic eruptions. It starts from Mount Erebus of Antarctica-Andes-Rockies-Alaska-Japan to Indonesia. Ex- Mount Cotopaxi
  • Mid Continental belt: where volcano mainly arises from convergence of continental plates and are explosives. Ex- Mount Kilimanjaro
  • Mid Atlantic belt: where volcanic activities due to splitting of plates. Ex- Helena Mountains (Iceland)

Thus, on basis of above analysis it can be said that volcanic areas mainly arises from disturbance in earthly crust and have a profound impact on environment.

Q. Wind plays a major role in formation of different erosional and depositional land forms. In this light discuss the various types of land topography formed due to action of wind.

Structure of the answer:

  • Introduction: Role of winds
  • Various erosional features
  • Various depositional features
  • Conclusion

Model Answer

The wind is the main geomorphic agent especially in the hot deserts. Winds have a dual role in creating Erosional landforms and other in creating Depositional landforms.

These geomorphic features are most typically found in arid environments where there is little vegetation, where there are frequently strong winds etc. The landforms which are created by erosional and depositional activities of wind are called as Aeolian Landforms.

The various erosional landforms are as follows:

  • Pediplains: The high relief structures in deserts are reduced to low featureless plains by the activities of wind.
  • Deflation Hollows: Deflation is the removal of loose particles from the ground by the action of wind. When deflation causes a shallow depression by persistent movements of wind, they are called as deflation hollows.
  • Ventifacts: These are rocks that have been abraded, pitted, etched, grooved, or polished by wind-driven sand.
  • Mushroom Tables: In deserts, a greater amount of sand and rock particles are transported close to the ground by the winds which cause more bottom erosion in overlying rocks than the top. This result in the formation of rock pillars shaped like a mushroom.
  • Other forms: Inselbergs, Zeugen (formed when more resistant rock is reduced at a slower rate than softer rocks), Yardangs (ridge of rock formed usually parallel to the prevailing wind direction.

The various depositional landforms created by winds are as follows:

  • Sand dunes: Dry hot deserts are good places for sand dune formation. There are varieties of sand dune forms like Barchans, Seifs
  • Parabolic dunes: They are U-shaped and are much longer and narrower than barchans.
  • Ripple Marks: These are depositional features on a small scale formed by saltation (transport of hard particles over an uneven surface in a turbulent flow of air).
  • Loess: When the surface is covered by deposits of wind-transported silt that has settled out from dust storms.

This suggest that the wind plays an important role in erosion and deposition and consequent formation of new land forms.

Q. Discuss the various features of tropical cyclones. While mentioning the factors contributing in formation of tropical cyclone differentiate them from extra-tropical cyclones.

Structure of the answer:

  • Introduction
  • Features of tropical cyclone
  • Factors contributing in formation of cyclones
  • Difference between tropical and extra tropical cyclones
  • Conclusion

Model Answer

Cyclone is an intense vortex or a whirl in the atmosphere with very strong winds circulating around it in anti-clockwise direction in the Northern Hemisphere and in clockwise direction in the Southern Hemisphere.  For Ex- Cyclone Titli

Some of the special characteristics of tropical cyclones are as follows:

  • Cyclones have intense low pressure areas and pressure increases outwards.
  • They mainly originate mainly in zones between 5– 30 °C Norther & South of latitude.
  • These originate over oceans in tropical areas & move to coastal areas.
  • They have large destructive force caused by violent winds, heavy rainfall & storm surges.
  • Tropical cyclones follow a parabolic path and its axis is parallel to the isobars.

Some of the necessary condition for the formation of tropical cyclones are as follows:

  • Continuous supply of abundant warm and moist air.
  • Sea temperature in lower latitudes should be around 27°C.
  • The cyclones require presence of large Coriolis force to deflect winds blowing toward the low pressure centre.
  • There must also be pre-existence of weak tropical disturbances.
  • Further, there should be presence of anticyclonic circulation at the height of 9 to 15 km above the surface.

However, the tropical cyclones are different from temperate cyclones in following ways:

  • Tropical cyclone is confined between 5-30° N-S of the equator, whereas temperate cyclone originate between 30 to 60° N-S of the equator.
  • Coriolis force plays vital role in the origin of tropical cyclone, whereas for temperate cyclone frontogenesis is the driving force.
  • Temperate cyclone covers large area as compared to tropical cyclone.
  • Tropical cyclone generally originates over water surface but the temperate cyclone originates over mid-latitude land mass.
  • Temperate cyclone generally moves eastward, while tropical cyclone moves from east to west.
  • Cyclone’s eye is a typical feature in case of tropical cyclone, while temperate cyclone have no such concept.

Thus, as cyclones carries destructive force there is a need for timely dissemination of warning and increasing preparedness of disaster management authorities.

Q. Oceans are the major sources for multiple living and non-living resources that are useful for the growth of blue economy. In this light discuss the concept of Blue economy and its importance for India.

Structure of the answer:

  • Introduction (Blue economy)
  • Ocean as the source for various resources
  • Importance of blue economy
  • Final analysis

Model Answer

The concept of blue economy was given by Gunter Pauli. It is the sustainable use of ocean resources for economic growth, improved livelihoods and jobs and ocean ecosystem health. Thus, it advocates the greening of ocean development for purposes of higher productivity and at same time conserving ocean’s health.

The oceans are the sources for various resources such as follows:

  • Oceans contain several varieties of fishes and sea weeds that have tremendous potential to be used for industrial and human activities.
  • Minerals derived from the oceans include Petroleum gas, shale gas, Magnesium, Sulphur, Poly-metallic nodules that are useful for industrial usage.
  • Maritime Transport constitute over 80% of international trade and commerce.
  • Ocean and coastal tourism are important source for job creation and economic growth.
  • Tides in ocean release a lot of renewable energy that can be used to operate a turbine and produce electricity. For ex.-
  • Further, oceans are an important carbon sink (blue carbon) and that can help mitigate climate change.

In light of above, the importance of blue economy for India is as follows:

  • Blue economy presents India with an opportunity to meet its national socio-economic objectives as well as strengthen connectivity with neighbors.
  • Blue Economy can help in livelihood generation, achieving energy security, building ecological resilience and improving living standards of coastal communities.
  • Blue economy can reinforce and strengthen efforts of Indian government to achieve the SDGs of hunger and poverty eradication by 2030.
  • Further, marine services sector could serve as the backbone of Indian economy and help it become 10 trillion-dollar economy by 2022.
  • Moreover, international practice of the countries such as Australia, China, Mauritius is also suggestive of the fact that of use of ocean/ blue economy for meeting their development objectives.

Thus, India and world as a whole should look to adopt the Gandhian approach of balancing economic benefits derived from blue economy for meeting the broader goals of growth, employment generation, equity and protection of environment.

Q. The large-scale occurrence of floods is a result of multitude of factors. In this background discuss the causes of floods and steps to minimise the vulnerability to floods.

Structure of the answer:

  • Introduction
  • Causes of floods
  • Steps to mitigate vulnerability
  • Conclusion

Model Answer

Flood is a state of higher water level along a river channel or on coast leading to inundation of land that is not normally submerge. In India, 40 million hectares out of a geographical area of 3290 lakh hectares is prone to floods. Moreover, every year, 1600 lives are lost and the damage caused to crops, houses and public utilities is Rs. 1800 crores due to floods.

The main causes for floods are as follows:

The rivers bring heavy sediment load from catchments. These, coupled with inadequate carrying capacity of rivers are responsible for causing floods.

  • Some of the general causes are drainage congestion, erosion of river-banks, silting in deltaic areas
  • Moreover, about 75% of the annual rainfall in India is concentrated in 3-4 months of the monsoon season. As a result, there is very heavy discharge from rivers during the period causing widespread floods.
  • Further, cyclones, cloud bursts, storm surge cause flash floods and lead to huge loss of life and property.
  • Lastly, in urban areas the urban flooding is caused by increasing incidence of heavy rainfall in a short period of time, indiscriminate encroachment of waterways, inadequate capacity of drains and lack of maintenance of the drainage infrastructure. For ex.- Chennai floods.

Steps to mitigate flood vulnerability are as follows:

  • There is a need for identification and marking of flood prone areas and preparation of close contour and flood vulnerability maps.
  • Further, this must be followed by implementation of the schemes for expansion and modernisation of the flood forecasting and warning network, execution of flood protection and drainage improvement schemes
  • The focus must also be on development of hard management techniques like dams, embankments or artificial levees
  • Further, flood walls/ River defences/ Coastal defences can be built around settlements to protect them from floods.
  • Lastly, the focus must also be on afforestation, proper land use management

Thus, the causes of the floods being natural and man made requires, thus to control and mitigate the same requires interdisciplinary approach. 

Q. Discuss the difference between Himalayas and Peninsular drainage system. Also put forth importance of the river system in India.

Structure of the answer:

  • Introduction
  • Difference between Himalayan and Peninsular river system
  • Importance of river system in India
  • Conclusion

Model Answer

Rivers are considered as the lifelines of a country as they provide the most valuable thing for the survival i.e. water. The rivers in India can be broadly categorized into two different categories based on their origin: the Himalayan Rivers and the Peninsular Rivers.

The difference between the two is tabulated below:

Himalayan RiversPeninsular Rivers
1.      These rivers originate from the Himalayan mountain ranges.1.      These rivers originate from the peninsular plateaus.
2.      They are longer and larger than the peninsular rivers.2.      They are comparatively smaller than the Himalayan Rivers.
3.      They have larger basins and catchment areas.3.      They have smaller basins and catchment areas.
4.      The bedrocks of these rivers are soft, sedimentary and easily erodible.4.      The bedrocks of these rivers is hard and not easily erodible.
5.      They are perennial in nature.5.      They are seasonal and non-perennial.
6.      They are fed by the meltwater from glaciers/ rains.6.      They are fed only by rains.
7.      They form V-shaped valleys.7.      They form U-shaped valleys.
8.      They form meanders.8.      They may not form meanders.
9.      They form big deltas.9.      They form small rivers and estuaries.
10.   They are antecedent rivers.10.   They are consequent rivers.

In light of the aforesaid, it is also important to discuss the importance of the rivers as such:

  • Rivers are the biggest source of fresh water for drinking.
  • Rivers provide fertile soil, which is important for increasing agricultural productivity.
  • Rivers are not only important for human beings but also for animals and trees. Various aquatic animals and plants breed in rivers, which is important to maintain the balance in the food chain.
  • These are also a source of energy as help generating electricity. For ex.- Bhakra Nangal Dam.
  • Rivers also help in improving the economy by providing cheap means of transportation.

Thus, considering the importance of river system and impending climate change, it is important that steps are taken to protect rivers.

Q. What do you mean by climate forcing? Explain the factors that causes the Earth’s climate to change.


  • Explain the meaning of climate forcing  and related phenomenon with relevant examples.
  • Discuss various natural and anthropogenic causes of climate change.
  • Conclude the answer, as per the context.

Model Answer

Any external factor that originates from outside the climate system and can become a cause of climate change is called Climate Forcing. These factors are specifically known as forcings because they drive the climate to change. There are natural forcings and man-made forcings. For examples:

  • Surface reflectivity (Albedo).
  • Human-caused, or anthropogenic climate  forcing include emissions of heat-trapping gases (also known as greenhouse gases) and changes in land use that make land reflect more or less sunlight energy. 
  • Atmospheric aerosols due to human activity or volcanic eruption etc. that put light-reflecting particles into the upper atmosphere.

The peculiar feature of all climate forcing is that they influence the balance of the energy entering and leaving the Earth system i.e, the amount of energy we receive from the sun, and the amount of energy we radiate back into space.  Climate change refers to the change of climate that alters the composition of the global atmosphere. It is usually measured in major shifts in temperature, rainfall, snow, and wind patterns lasting decades or more.

The causes of climate change can be classified into two types; natural and anthropogenic.

Natural causes:

  • Solar Irradiance: The change in energy output of the sun brings changes in climate. Solar output varies according to the 11 year solar cycle.
  • Volcanic Eruptions: When volcanoes erupt, thousands of tons of sulfur dioxide is released into the atmosphere which cause cooling and warming of the earth respectively.
  • Plate tectonics: Tectonic plates rearrange the topography of the earth which  brings changes in the circulation of oceans and subsequently changes the patterns of the global climate.  
  • Variations in the Earth’s Orbit: Variations in the orbit of the planet bring changes in seasonal and geographical distribution of the light from the sun that affects the global climate.

Anthropogenic causes:

  • Emission of Greenhouse Gases: Release of greenhouse gases like Carbon dioxide is one of the main reasons for climate change.  For example, human activities such as deforestation, burning of fossil fuels, surface mining, agriculture, emissions from industries etc. are also releasing other greenhouse gases into the atmosphere.
  • Land Use Change: Climate change is also assisted by changes in land use and land cover that are caused because of human activities such as agriculture.

Many of these factors are interrelated, and atmospheric, ocean and land interactions can involve complex feedback mechanisms can either enhance or dampen changes to the climate system.

About: Krishna Godavari basin

About: Krishna Godavari basin

  • The delta plain formed by Krishna and Godavari rivers in the state of Andhra Pradesh and the adjoining areas of Bay of Bengal is known as Krishna Godavari Basin.
  • It is a proven hydrocarbon reserve, with an inland part that covers an area of 28,000 sq. km and an offshore (located in the sea or near the coast) part that covers an area of 2 lakh sq. km.
  • Several oil and gas fields are located both on land and offshore parts of the basin.
  • The region is primarily known for the D-6 block where Reliance Industries discovered the biggest natural gas reserves in India.

In News

  • Reliance Industries Ltd (RIL) and British Petroleum (BP) have announced the start of gas production from R cluster in the Krishna Godavari D6 (KG-D6) block.
  • Located at a depth of more than two kilometres, the R Cluster is the deepest offshore gas field in Asia.
  • R Cluster is the first of three deep water gas projects in the KG-D6 block jointly developed by RIL and BP. The other two clusters are Satellites Cluster and MJ.
  • Production of gas from the R cluster was expected to start in May 2020 but was delayed due to the impact of the Covid-19 pandemic. The Satellite cluster is expected to start production in 2021.
  • RIL has a participating interest of 66.7% in the KG-D6 block and BP has a participating interest of 33.3% in the block.


  • In FY20, demand for natural gas in India was around 153 MMSCMD and around half the demand was met through imports.
  • Increasing domestic production of natural gas is important to reduce India’s dependence on imports and improve energy security.
  • The three clusters mentioned above are a key part of the plan to boost domestic production of natural gas and to increase the share of natural gas in India’s overall energy consumption from 6.2% now to 15% by 2030.
  • The three clusters in the Krishna Godavari Basin are expected to produce around 30 MMSCMD (Million standard cubic metres per day) of natural gas or about 15% of India’s projected demand for natural gas by 2023.
  • The R cluster field alone is expected to have a peak production of 12.9 MMSCMSD or about 10% of India’s current natural gas output.

Boosted by changes to gas tariff structure:

  • Recent changes in the formula for gas transport tariffs acted as additional incentive to Reliance and BP’s investments in these three fields.
  • Earlier, the tariff was based on the distance of transportation of gas – the longer the distance, the higher the charge.
  • However, the new regulations have a two-zone tariff structure. There will be one tariff for gas transported within 300 kms and another tariff for gas transported beyond 300 kms from the source of the natural gas.
  • This will help to make the gas more affordable to customers who are far away from the source of the gas.

Rivers and their tributaries:-

Rivers and their tributaries:-

1)Tributaries of Ganga:
1. Gomti 2. Ghaghra 3. Gandak 4. Kosi 5. Yamuna 6. Son 7. Hoogly

2)Tributaries of Yamuna:
1. Chambal 2. Sindh 3. Betwa 4. Ken 5. Tons 6. Hindon

3)Tributaries of Godavari:
1. Indravati 2. Manjira 3. Bindusara 4. Sarbari 5. Penganga 6.Pranahita

4)Tributaries of Krishna:
1. Tungabhadra 2. Ghataprabha 3. Malaprabha 4. Bhima 5. Vedavati 6. Koyna

5)Tributaries of Cauvery:
1. Kabini 2. Hemavathi 3. Simsha 4. Arkavati 5. Bhavani

6)Tributaries of Narmada:
1. Amaravati 2. Bhukhi 3. Tawa 4. Banger

7)Tributaries of Indus:
1. Sutlej 2. Dras 3. Zanskar 4. Shyok 5.Gilgit 6. Suru

8)Tributaries of Brahmaputra:
1. Dibang 2. Lohit 3. Jia Bhoreli (Kameng) 4. Dikhow 5. Subansiri 6. Manas

9)Tributaries of Damodar:
1. Barakar 2. Konar

10)Tributaries of Ravi:
1. Budhil 2. Nai or Dhona 3. Seul 4. Ujh

11)Tributaries of Mahanadi:
1. Seonath 2. Hasdeo 3. Jonk 4. Mand 5. Ib 6. Ong 7. Tel

Geography Concepts

El Nino :-

El- Nino is Spanish word for male child ( Christ Child)

El Nino refers to two things:-
1. ceasing of upwelling off west coast of South America (Eastern Pacific Ocean)

2. appearance of warmer waters than average on the surface of ocean off the west coast of South America.

Statistically, El-nino has been found have a negative correlation with India’s summer monsoon rains.

La- Nina:-
Spanish word for Girl Child and refers to the reinforce or augmented or strengthened normal situation in the Eastern Pacific Ocean
Statistically, La- Nina has been found to have positive correlation with India’s summer monsoon rains.

Walker Cell:-
Term walker cell in general refers to prominent east west pressure cell of atmospheric circulation ( especially in tropical areas)

Southern Oscillation:-
It’s given by Sir Gilbert Walker
It refers to sea saw arrangement of atmospheric pressure conditions between Pacific and Indian Ocean.

Southern Oscillation Index :-
(Tahiti’s Atmospheric pressure ) – (Darwin’s atmospheric pressure)

Landform term refers to the earth’s surface configuration e.g Hill, Valley, Plateau, Plain etc…
A given landscape in nature represents stage of external fight between endogenic and exogenic process.

Sun is primary source of energy for exogenic processes.
It’s generally believed that radiative disintegration of element is primary source of energy for endogenic processes.

Endogenic and exogenic processes are collectively referred as geomorphic processes.

Geography Concepts

At sea, ITCZ area is called doldrums because sailors in olden days used to get becalmed here.
It’s the region of weak winds (small pressure gradients), High Humidity and High Temperatures occuring heat near equator.

Horse Latitude:-
In olden days, Zones at about 30 N/S Degree were known as Horse latitude.
When ships were becalmed, horses were thrown to reduce the load.
Here, the air is comparatively dry and winds are calm and light, because of small pressure gradient force.
It’s the region of descending air currents or wind divergent ie. Anti-Cyclonic condition.

Trade Winds:-
Trade winds are most regular of all the planetary winds and in general they blow with great force and in constant direction.

Since trade winds blow from the subtropical latitudes to the warmer equatorial latitudes, they have great capacity of holding moisture.

In their passage across oceans, they gather more moisture and bring heavy rainfall to the east coast of continents.

As their offshore on the west coast, these regions suffer from great aridity and form hot deserts of the world.
E.g. Sahara, Kalahari, Atacama, Great Australian deserts.

Interior area of Australia
The term outback in Australia refers to dry interior region.
Term outback implies “Never Never” ( Never Never go there)

Westerlies are much less ( constant and persistent) than trade winds.

Seismic Gap:-
It’s the earthquake prone area where occurs a gap in the occurrence record of major earthquakes.
This means, that statistically, major earthquake is due ie, much more time had elapsed since the last major earthquake than the average time gap between two major earthquake as per the historical occurances.

Earthquake waves gets significantly amplified when they passed through soft grounded ( water saturated alluvial deposits).
Liquefaction is sudden loss of strength of water saturated soils resulting from shaking during an earthquake.
It can cause large ground cracks to open, shaking can cause soils to consolidate and thus to occupy a smaller volume.
During shaking of an earthquake, the water saturated material may result in subsidence, fracturing and horizontal sliding of the ground surface.

Headline : Prelims Program: Map- Argentina

Headline : Prelims Program: Map- Argentina

Details :

Why it is important?

  • Argentina hosted the recent G20 summit in 2018.
  • In Feb 2019, Argentina’s President paid a state visit to India. 2019 is the 70th year of establishment of diplomatic relations between the two countries.



  • Argentina is located mostly in the southern half of the South America.
  • Argentina derives its name from the Latin word for silver, Argentum as Argentina is a great source of valuable minerals.
  • Capital: Buenos Aires
  • Argentina is the eighth-largest country in the world and second largest country of South America after Brazil.
  • It shares boundary with : Chile (to the west), Bolivia and Paraguay (to the north); Brazil (to the northeast), Uruguay and the South Atlantic Ocean (to the east) and the Drake Passage (to the south).



Note: The Drake Passage is a narrow body of water between Antarctica and South America. It connects Atlantic Ocean and Pacific ocean.


  • Its geography is dominated by :
    • Andes mountain range in the west, forming boundary between Chile and Argentina.
    • Gran Chaco lowlands in the north (famous for Quebrancho tree)
    • Pampas grasslands in the centre(one of the most fertile grasslands of the world: famous for Wheat, maize and linseed cultivation)
    • Patagonia Plateau to the south.


Note: Trans Andean Railway line provide railway transport over the Andes,  connecting Chile and Argentina.

  • Important rivers:
    • Colorado River flows in south of Argentina, generally east -southeast across the arid terrain of northern Patagonia and the southern Pampas.
    • Parana River runs through Brazil, Paraguay and Argentina. It is the second longest river in South America. It drains into Rio de la Plata and Atlantic Ocean.
    • Uruguay River passes through Argentina, Brazil and Uruguay. It drains into Rio de la Plata and Atlantic Ocean.

Note: Together with the Paraná River, the Uruguay forms the Río de la Plata estuary.

  • Climate:
    • Temperate climate in general
    • Temperature decreases from north to south and from east to west.
  • Vegetation: Grass is the chief vegetation of Argentina.
  • Monte Desert is a small desert above the Patagonian Plateau.




Section : Miscellaneous

Prelims Program: Indus River System

Details :

Why it is important?

  • In view of the Pulwama attack, India is weighing its options for retaliation against Pakistan, who sponsored the attack.Out of many options, one big move that India can take is to abrogate the Indus Waters Treaty (which deals with river Indus and its five tributaries).

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Indus River System

  • It is one of the most important rivers on the Indian subcontinent.
  • Origin: The Indus River originates near the Mansarovar Lake in the Tibetan plateau, on the northern slopes of the Kailash Mountain Range.
  • Length of the river: 3200 kilometer (2000 mile)
  • It passes through Ladakh district in Kashmir.
  • Subsequently, the river gets into Pakistan running across the North in a southward route down the whole span of Pakistan, to join the Arabian Sea.
  • Left- bank tributaries (joins the main river from left side): Zaskar river, Suru river, Soan river, Jhelum river, Chenab river, Ravi river, Beas river, Satluj river are its major left-bank tributaries.
  • Right- bank tributaries (joins the main river from right side): The Shyok river, Gilgit river, Hunza river, Swat river, Kunnar river, Kurram river and Kabul river are its major right-bank tributaries.
  • The name Punjab has been derived from these tributaries that collectively signify “five waters” or “land of five waters”. The five rivers or Panjnad after which Punjab is named are the Jhelum, Chenab, Ravi, Beas, and the Sutlej.


Five main tributaries of the Indus River:


  • Source: Spring at Verinag.
  • The river runs through the Wular lake and Srinagar in India, prior to moving into the Punjab province of Pakistan.
  • Important Dam: Uri dam (J&K)


  • Source: River Chandra and river Bhaga rise on the opposite sides of the Baralacha pass and meet at Tandi (H.P) to from Chenab.
  • In Himachal Pradesh, the river is also called the Chandrabhaga.
  • It flows parallely to the Pir Panjal Range.
  • The river cuts a deep gorge near Kistwar,
  • It enters the plain area near Akhnur in Jammu and Kashmir and is subsequently connected with the Jhelum.
  • It creates the border between the Rechna (between Ravi and Chenab) and the Jech (between Jhelum and Chenab) Doabs.
  • The Chenab also meets the Ravi and the Sutlej in Pakistan.
  • Imp Dams: Baglihar Dam (J&K), Dulhasti Dam (J&K), Salal Dam (J&K)

Sutlej (Satluj)

  • Source: Rakshas Tal or Rakas Lake, which is linked to the Manasarovar Lake with a watercourse in Tibet.
  • Through Shipkila pass the river Satluj enters India from Tibet
  • It cuts a gorge in Naina Devi Dhar, where Bhakra dam has been constructed. Later it enters the Punjab plains.
  • Beas joins the Satluj at Harike and in Pakistan, Ravi, Chenab and Jhelum rivers also adds their water into Satluj before it joins the Indus.
  • Imp Dams: Bhakra dam (H.P.) and Kol Dam (H.P.)


  • Source: Kullu hills near Rotang pass
  • The river drains the area between Pir Panjal and Dhaola Dhar ranges.
  • It enters plains near Madhopur (Punjab) and later enters Pakistan.
  • Imp Dams: Ranjit Sagar Dam(Punjab), Shahpur Kandi Dam(Punjab), Bassi Dam (H.P.), Chamera Dam (H.P.)


  • Source: Bias Kund near Rohtang pass.
  • The river flows across Kulu and Manali,
  • The Beas meets the Sutlej river close to Harika, after being connected with some tributaries.
  • River Beas lies entirely within the Indian territory.
  • Imp Dams: Pong Dam (H.P.), Pandoh Dam (H.P.),


Important Term

Doab: The tract of land lying between two converging, or confluent, rivers

Punjab Doabs

Each of the tracts of land lying between the confluent rivers of the Punjab region of India and Pakistan has a distinct name

The names (except for ‘Sindh Sagar’) are a combination of the first letters, in the Persian alphabet, of the names of the rivers that bound the Doab. For example, Jech = ‘Je'(Jhelum) + ‘Ch'(Chenab).



Section : Miscellaneous

Why a dam in Karnataka bothers Tamil Nadu

Headline : Why a dam in Karnataka bothers Tamil Nadu

Details :

Why in news?

  • Recently, Tamil Nadu Chief Minister E K Palaniswami wrote to the Prime Minister urging him to stop the process of a feasibility study for the Mekedatu dam project in Karnataka.


About Mekedatu dam project

  • Being set up by the Karnataka government, the project is near Mekedatu, in Ramanagaram district, across the river Cauvery from Tamil Nadu.
  • Its proposed capacity is 48 TMC (thousand million cubic feet).
  • Its primary objective is to supply drinking water to Bengaluru and recharge the groundwater table in the region.




  • The dispute between Karnataka and Tamil Nadu over the sharing of Cauvery waters is decades old.
  • For many years, both the states have been maintaining differences over the sharing of water.
  • Karnataka intends to build Mekedatu reservoir across river Cauvery near Mekedatu in Kanakapura taluk.
  • However, Tamil Nadu objected saying Karnataka had not sought prior permission for the project. Its argument was that the project would affect the flow of Cauvery water to Tamil Nadu.
  • In November 2014, the Karnataka government invited expressions of interest in the Rs 6,000-crore project. In its 2015 Budget, it allocated Rs 25 crore for a detailed project report.
  • Tamil Nadu saw massive protests in 2015, including a state-wide bandh backed by political parties, farmers, transport unions, retailers and traders.
  • The T.N. Assembly also adopted a unanimous resolution urging the Centre to stop Karnataka from building the project.
  • Ahead of the 2016 Assembly polls in Tamil Nadu, delegation of Opposition leaders met the Prime Minister against Karnataka’s decision to allocate Rs 25 crore for a feasibility study.
  • From Karnataka, then Chief Minister Siddaramaiah led an all-party delegation to the Prime Minister seeking the Centre’s cooperation in going ahead.
  • The study has been cleared by the Central Water Commission (CWC), which has also asked for a detailed project report.
  • The process cleared by the CWC needs further clearance from the Cauvery Water Management Authority (CWMA) too.



  • The CWC clearance is for a report subject to certain conditions, which include the concerns raised by the Tamil Nadu government.
  • The detailed report has to consider the views of the co-basin states as well.


Why Tamil Nadu is opposing the project?

  • Its main argument is that the project violates the final award of the Cauvery River Water Tribunal, and that the construction of the two reservoirs would result in impounding of the flows in the intermediate catchment below the Krishnaraja Sagar and Kabini reservoirs, and Billigundulu in the common border of Karnataka and Tamil Nadu.


Arguments given by Karnataka government

  • According to Karnataka, project will not come in the way of releasing the stipulated quantum of water to Tamil Nadu, nor will it be used for irrigation purposes.



Section : Polity & Governance

Tropical Evergreen Forests Conditions for growth:

Tropical Evergreen Forests Conditions for growth:

Tropical Evergreen and Semi Evergreen Forests are found mainly in the areas where the annual rainfall is more than 250 cm, with a short dry season. The average annual temperature should be above 22 °C.

Characteristics: Lofty, very dense, multi-layered forest with mesophytic evergreen, 45m or more in height, with large number of species, numerous epiphytes, and few climbers; Due to dense growth of trees, the sunlight cannot reach the ground. Thus, the undergrowth mainly consists of canes, bamboos, ferns, climbers, etc.

Location: The true evergreen forests are mostly found along the western slopes of Western Ghats, in the hills of north-eastern states and in the Andaman and Nicobar Islands.

Trees: Important trees of these forests are rosewood, ebony, mahogany, rubber, cinchona, bamboo, coconut, palms, canes, lianas, etc.

Utility: Not commercially exploitable. However, the timber from the tropical evergreen and semi- evergreen a forest is hard, durable, fine-grained and of high economic value.

Hydroelectric Projects in India

Consider the following statements about Kishenganga River

1.      It is a tributary of river Satluj

2.      It is called Neelum in Pakistan

Select the correct statements

a       Only 1

b       Only 2

c       Both 1 and 2

d       Neither 1 nor 2


Solution (b)

The Jhelum has its source in a spring at Verinag in the south-eastern part of the Kashmir Valley. It flows northwards into Wular Lake (north-western part of Kashmir Valley). From Wular Lake, it changes its course southwards. At Baramulla the river enters a gorge in the hills. The river forms steep-sided narrow gorge through Pir Panjal Range below Baramula. At Muzaffarabad, the river takes a sharp hairpin bend southward. Thereafter, it forms the India-Pakistan boundary for 170 km and emerges at the Potwar Plateau near Mirpur. After flowing through the spurs of the Salt Range it debouches (emerge from a confined space into a wide, open area) on the plains near the city of Jhelum. It joins the Chenab at Trimmu.

The Kishenganga (Neelum) River, the largest tributary of the Jhelum, joins it, at Domel Muzaffarabad

Kishanganga Hydroelectric Plant

It is a dam which is part of a run-of-the-river hydroelectric scheme that is designed to divert water from the Kishanganga River to a power plant in the Jhelum River basin

Kishenganga is a river in the Kashmir region of India and Pakistan; it starts in the Indian city of Gurais and then merges with the Jhelum River near the Pakistani city of Muzaffarabad. When Kishanganga enters Pakistan, it is called “Neelam river.”

Ratle Hydroelectric Plant

The Ratle Hydroelectric Plant is a run-of-the-river hydroelectric power station currently under construction on the Chenab River, downstream of the village of Ratle in Doda district of the Indian state of Jammu and Kashmir.

The Chenab River is a major river of India and Pakistan. It forms in the upper Himalayas in the Lahaul and Spiti district of Himachal Pradesh, India, and flows through the Jammu region of Jammu and Kashmir into the plains of the Punjab, Pakistan. The waters of the Chenab are allocated to Pakistan under the terms of the Indus Waters Treaty.

Pakal Dul Dam

The Pakal Dul Dam is a proposed concrete-face rock-fill dam on the Marusadar River, a tributary of the Chenab River, in Kishtwar district of the Indian state of Jammu and Kashmir.

Pakistan, who relies on the Chenab downstream, views the dam as a violation of the Indus Water Treaty, whereas India states it is as per Treaty Provisions.

Lower Kalnai Hydroelectric Project

Hydroelectric power project on Lower Kalnai Nalla, tributary to river Chenab in Doda district of Jammu & Kashmir.

Miyar Hydroelectric Project

Miyar Hydroelectric Project is located in District Lahaul and Spiti, Himachal Pradesh on the Miyar Nallah which is a major tributary of Chenab River.

Baglihar Dam

It is a run-of-the-river power project on the Chenab River in the southern Doda district of the Indian state of Jammu and Kashmir.

Geography – Seismic Gap, Liquefaction

Seismic Gap:-
It’s the earthquake prone area where occurs a gap in the occurrence record of major earthquakes.
This means, that statistically, major earthquake is due ie, much more time had elapsed since the last major earthquake than the average time gap between two major earthquake as per the historical occurances.

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Earthquake waves gets significantly amplified when they passed through soft grounded ( water saturated alluvial deposits).
Liquefaction is sudden loss of strength of water saturated soils resulting from shaking during an earthquake.
It can cause large ground cracks to open, shaking can cause soils to consolidate and thus to occupy a smaller volume.
During shaking of an earthquake, the water saturated material may result in subsidence, fracturing and horizontal sliding of the ground surface.

Geography Concept:- Trade Winds, Outback

Trade Winds:-
Trade winds are most regular of all the planetary winds and in general they blow with great force and in constant direction.

Since trade winds blow from the subtropical latitudes to the warmer equatorial latitudes, they have great capacity of holding moisture.

In their passage across oceans, they gather more moisture and bring heavy rainfall to the east coast of continents.

As their offshore on the west coast, these regions suffer from great aridity and form hot deserts of the world.
E.g. Sahara, Kalahari, Atacama, Great Australian deserts.

Interior area of Australia
The term outback in Australia refers to dry interior region.
Term outback implies “Never Never” ( Never Never go there)

Brief about El Nino, La Nino, Southern Oscillation, Walker Cell

El Nino :-

El- Nino is Spanish word for male child ( Christ Child)

El Nino refers to two things:-
1. ceasing of upwelling off west coast of South America (Eastern Pacific Ocean)

2. appearance of warmer waters than average on the surface of ocean off the west coast of South America.

Statistically, El-nino has been found have a negative correlation with India’s summer monsoon rains.

La- Nina:-
Spanish word for Girl Child and refers to the reinforce or augmented or strengthened normal situation in the Eastern Pacific Ocean
Statistically, La- Nina has been found to have positive correlation with India’s summer monsoon rains.

Walker Cell:-
Term walker cell in general refers to prominent east west pressure cell of atmospheric circulation ( especially in tropical areas)

Southern Oscillation:-
It’s given by Sir Gilbert Walker
It refers to sea saw arrangement of atmospheric pressure conditions between Pacific and Indian Ocean.

Southern Oscillation Index :-
(Tahiti’s Atmospheric pressure ) – (Darwin’s atmospheric pressure)

Grography – ITCZ, Doldrums, Horse Latitude

At sea, ITCZ area is called doldrums because sailors in olden days used to get becalmed here.
It’s the region of weak winds (small pressure gradients), High Humidity and High Temperatures occuring heat near equator.


Horse Latitude:-
In olden days, Zones at about 30 N/S Degree were known as Horse latitude.
When ships were becalmed, horses were thrown to reduce the load.
Here, the air is comparatively dry and winds are calm and light, because of small pressure gradient force.
It’s the region of descending air currents or wind divergent ie. Anti-Cyclonic condition.

ITCZ – Inter Tropical Convergence Zone

ITCZ is a zone where the trade winds converge. It’s also referred as the Thermal Equator.
ITCZ can be found as much as 20 degree north of equator in July and 10 degree south of equator in January.

The exceptional shift in ITCZ by 20 degree is seen in South Asia during Summer Season. The exceptional shift of ITCZ plays a significant role in the causation of summer monsoon in South ASIA.

ITCZ is a zone of calm, hot, rising air and low pressure area.

Quiz-Q19. Consider the following pairs: Which of the pairs given above is/are correctly matched?

Q19. Consider the following pairs: Which of the pairs given above is/are correctly matched?

Ocean Current Coast Affected

1. Humboldt – Brazil

2. Aghulas -Africa

3. Irminger -USA

A. 1 and 2 only

B. 2 and 3 only

C. 2 only

D. 1 and 3 only

Answer: C

Exp: Ocean currents are large masses of surface water that circulate in regular patterns around the oceans. Those that flow from equatorial region towards pole are warm currents as they have higher surface temperature. Those that flow from polar regions towards equator are cold currents as they have lower surface temperature. The Humboldt Current, also called the Peru Current, is a major Eastern Boundary Upwelling Ecosystem that flows north along the western coast of South America. It is an eastern boundary current flowing in the direction of the equator, and extends 500-1,000 kilometers offshore. The Agulhas Current is the western boundary current of the southwest Indian Ocean. It flows down the east coast of Africa from 27°S to 40°S. It is narrow, swift and strong. The Irminger Current is a North Atlantic ocean current setting westward off the southwest coast of Iceland. It is composed of relatively warm and saline waters from the eastern North Atlantic that are fed by the North Atlantic Drift.

Quiz- Q17. Consider the following statements:

Q17. Consider the following statements:

1. Highest peak in the Western Ghats is Anamudi.

2. The Aravalli range is an example of block mountain.

3. Guru Shikhar is the highest peak in the Abu hills.

Which of the statements given above are correct?

A. 1 and 2 only

B. 2 and 3 only

C. 1 and 3 only

D. None of the above

Answer: C

Exp: Anamudi is a mountain located in the Indian state of Kerala. It is the highest peak in the Western Ghats and South India, at an elevation of 2,695 metres (8,842 ft). Aravalli ranges are an example of old fold mountains located in Rajasthan. Guru Shikhar, a peak in the Abu hills of Rajasthan rises to an elevation of 1,722 metres (5,650 ft).

Everything about Steel Sector

About Steel sector

• In 2016-17, India’s total ‘Finished Steel Production’ for sale was around 100 MT with an apparent consumption of about 85 MT. Thus production of finished steel was sufficient to meet its present demand in the country and also for exports.

• The domestic steel sector contributes around 2% of the country’s GDP and employs over 6 lakh people.

• As per The World Steel Association (worldsteel) report-2017, India ranked third with 95.6 Million Tonnes (MT) in world total steel production of 1630 MT. China with 808 MT and Japan with 105 MT are ahead of India.

• India has very low per capita steel consumption i.e. 65 kg, (US-750; China-400+; World-216), hence steel sector has huge potential.


• Over the last few years, the Steel sector has been adversely impacted by the global steel glut which resulted in predatory pricing and a surge in steel imports into the country.

• Because of which, various projects failed and steel sector accounts for almost 30% of the non-performing assets of the banking industry.

• However, on account of timely intervention by the Government and industry through various trade related measures like anti-dumping and safeguards as well as other policy initiatives, the impact of the global glut were significantly mitigated.

Government Initiatives for Steel sector

• Steel being a de-regulated sector, the role of Government is that of a facilitator only.

• Government lays down the policy guidelines and establishes the institutional mechanism/structure for creating conducive environment for improving efficiency and performance of the steel sector.

• The Government has been proactive in ensuring adequate raw material availability at reasonable prices and explored ways of reducing input, logistic and infrastructure cost of Steel production.

• In order to provide level playing field to domestic steel sector, Government has taken various measures which are as under:

• In 2015, an Anti-Dumping Duty and a provisional safeguard duty was levied on imports of certain variety of products.

• In 2016, Government imposed Minimum Import Price (MIP) on many steel products. Government hiked import duty on various finished and semi-finished steel products.

• This year too, the government safeguarded the interests of domestic players by imposing a 4% additional dumping duty and a 1% countervailing duty.

• The Government has released the National Steel Policy 2017, which has laid down the broad roadmap for encouraging long-term growth for the Indian steel industry.

The National Steel Policy 2017 

• Policy was rolled out to enable the domestic steel industry to reach a capacity of 300 million tonnes (mt) by 2030-31 (against 126 mt now) through concept of Special Purpose Vehicle(SPV)  while setting global benchmarks in terms of quality and technology.

• The policy on preference to Domestically Manufactured Iron and Steel Products aims at facilitating consumption of domestic value-added steel in government procurement in sectors such as oil & gas, shipping, ports and airports.

• The policy mandates value addition of 15% on imported steel to qualify for bidding in government projects.

• Four mineral rich states namely Chhattisgarh, Odisha, Karnataka and Jharkhand have been identified for setting up of Integrated Steel Plants with the collaboration of Central and State PSUs through SPV route.

Steel sector: Year-2017

• The commencement of a long overdue restructuring of the Indian steel industry may be seen as one of the sectoral milestones of 2017.

• The year also saw two policy interventions by the government:

• aimed at boosting domestic production and

• consumption of value-added steel in government projects.

• Several steel companies, including some promoted by big corporate houses, were referred to the National Company Law Tribunal (NCLT) under the Insolvency and Bankruptcy Code.

• These happened at a time when the domestic industry regained its fundamentals amid strong export demand and a revival of the domestic market.


Increase in production: Production of finished steel grew by 8.5% over previous financial year whereas consumption grew by 2.6% in 2016-17.

Higher margins: In financial performance, steel firms have started realising higher operating margins on the back of improved domestic and international steel prices.

Domestic factor: Domestic prices improved significantly during the year. Value addition and increased branding saw a thrust from all major firm.

Increase in export: Exports amounted to 8.9 million tonnes in the first 10 months of calendar 2017, against imports of 6.6 million tonnes of finished steel. Indian exporters got a bigger export market at a time when overall sentiment was good. India was net exporter of steel in 2016-17.

Improvement in quality: Indian steelmakers also became more competitive during the year on grounds of quality and their deliveries. Many manufacturers harnessed advanced technology to augment quality.

Solar storms:

Solar storms:

It could refer to the following:

  • Coronal mass ejection: Corona, the outer solar atmosphere, is structured by strong magnetic fields. Where these fields are closed, often above sunspot groups, the confined solar atmosphere can suddenly and violently release bubbles of gas and magnetic fields called coronal mass ejections.
  • Solar flares: These are intense burst of radiations coming from the release of magnetic energy associated with sun spots.
  • (Sun spots: These are the dark areas on the solar surface, contain strong magnetic fields that are constantly shifting. They are as large as the Earth. Sunspots form and dissipate over periods of days or weeks.)

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Relationship of solar storms to magnetic shifts on Earth:

  • The solar storms contain large amounts of charged particles and radiation.
  • When they hit the Earth’s upper atmosphere, they produce the spectacular displays of the polar lights over the Arctic.
  • This is the region with the most geomagnetic disruption on Earth.
  • This way, the original magnetic field of the Earth gets distorted and this results in magnetic shifts.
  • The most powerful storms can also damage communications systems and satellites.
  • They can also impact the navigating abilities of birds and bees.

Buxa Tiger Reserve:

Buxa Tiger Reserve:

  • It is located in Alipurduar district of West Bengal.
  • It was notified as a tiger reserve in 1983.
  • The tiger reserve has an area of about 758 sq km. Out of this, 390 sq km lies in the core area and 367 sq km in the buffer zone.
  • Some parts of the reserve share a border with Bhutan.
  • Human population- There are about 38 villages in Buxa and 49 villages in the fringe area.
  • Types of forests – It consists of moist, deciduous and evergreen forests.
  • Species Diversity- It has at least 68 species of mammals, 41 species of reptiles and more than 246 species of birds, four species of amphibians, 73 species of fishes and over a hundred species of butterflies and moths.

Tropic of Cancer 

Tropic of Cancer passes through below countries

N America

  • Mexico
  • Bahamas


  • Western Sahara
  • Mauritania
  • Mali
  • Algeria
  • Niger
  • Libya
  • Egypt

 Middle East

  • Saudi Arabia
  • UAE
  • Oman


  • India
  • Bangladesh
  • Myanmar
  • China
  • Taiwan


Equator: passes through below Countries

S America

  • Ecuador
  • Colombia
  • Brazil

 Africa –

  • Sao Tome & Principe
  • Gabon
  • Republic of the Congo
  • Democratic Republic of the Congo
  • Uganda
  • Kenya
  • Somalia
  • Maldives

Asia –

  • Indonesia
  • Kiribati

Biomes of the World

Equatorial Zone

Equatorial rainforest – around equator

  • Amazon rainforest, Congo basin, and east indies
  • Uniform weather through out the year
  • Rains in the afternoons
  • Double rainfall peaks coinciding with the equinoxes
  • Canopy structure – layered trees
  • Epiphytes
  • Unfertile soil
  • Abundance of species
  • Difficult to penetrate the jungle
  • Cloud Forests – relates to Selvas
  • Hardwood trees – mahogany, rosewood, rubber, ebony etc.
  • Major Tribal groups :
    • Malaysia – Semang
    • Sumatra – Kubus
    • Borneo – Dayaks
    • Congo Basin – Pygmies
    • South America – Amazon Indians


Hot Zone


  • Evaporation exceeds precipitation
  • Hot desert – around west coasts, around offshore trade winds zone, cold ocean currents influence, hot days, cold nights
  • e.g.. Atacama desert, Sahara, great Australian desert, Mohave desert, Kalahari desert
  • Mid latitude desert – continentalism e.g.. Gobi desert / rain shadow e.g. Patagonia desert
  • Scanty rainfall
  • Large roots, wide spread shallow roots
  • Oil rich countries
  • Camel dependent
  • E.g. Dubai
  • Major Tribal groups
    • Western Sahara – Tuaregs
    • Arabian Desert – Bedouins
    • Kalahari – Bushmen
    • Australia – Bindibus


Savannah or Sudan/ tropical grassland

  • Africa – national geo shot
  • Masai – cattle pastoralist – on the run – cattle as their god
  • Hausa – settled cultivators
  • Tall grasses and short trees a.k.a elephant grass
  • Distinct weather – wet summer and Dry winter
  • Llanos – Venezuela
  • Campos – Brazil


Tropical monsoon

  • India
  • Dry, cold winter
  • Wet and humid summer
  • South west monsoon and retreating NE monsoon – seasonal reversal of winds
  • Broad leaves deciduous trees
  • Teak, sal, rosewood, bamboos, deodar


Tropical marine

  • Around east coasts, trade winds
  • Burma teak famous, spices, tea and coffee plantations, sugar cane, bamboo trees


Warm Temperate Zone

Warm temperate – Mediterranean

  • Med region, SFO, south Chile, south west Australia and Africa
  • Influenced by westerlies and movement of ITCZ
  • Hot summer and wet winter 
  • World’s orchard land
  • Known for wines, orchids and grapes – Viticulture
  • Sclerophyllous vegetation is best developed here
  • Walnut, Figs, Chestnut, Almond, Cedar are found
    • California – Chapparal
    • Europe – Maquis
    • South Africa – Fynbos


Steppe grassland – temperate grassland

  • Prairie – America
  • Pampas – Argentina
  • Pustaz – Hungary
  • Steppe – Russia
  • Veld – South Africa
  • Downs – Australia
  • Canterbury – NZ
  • Wheat and pastoral
  • Short grasses – dairy industry, cheese
  • Granaries of the world
  • Major Tribal Groups
    • Central Asia – Kirghiz
    • North America – Red Indians
    • South Africa – Hottentots


Eastern warm temperate – China type

  • Gulf type – SE America – Florida, NC, SC, Indiana etc.. , south Japan
  • natal type
  • Influenced by monsoon
  • Cotton, tobacco and corn in gulf
  • Rice in South East China
  • Affected by tropical cyclones and hurricanes
  • Mulberry thrives the best in this region


Cool Temperate Zone

Cool temperate – British type – temperate deciduous

  • Vancouver BC, Seattle areas, Britain
  • Four seasons – winter, spring, summer and fall
  • Deciduous trees
  • Salmon fish
  • Shed leaves
  • Oak, Elm, maple, beech and birch are the trees found here


Temperate evergreen/ coniferous/ boreal/ taiga

  • Around Southern Alaska, Canada, Siberia
  • East west stretch – largest biome on the land
  • Absent in southern hemisphere
  • Pine, spruce, fir trees – coniferous trees
  • Needle shaped trees
  • Olympic national park, Banff national park etc..
  • Soft wooded trees
  • Wood and pulp industry – lumbering


Eastern cool temperate – Laurentian type

  • NE America and north Japan
  • Greatest fishing zones of the world
  • Warm and cold current meet
  • Have best technologies in fishing
  • Absent in southern hemisphere – continent tapers down
  • Japan
    • Non agri land
    • Protein source of fish
    • Currents meet, technology in fishing


Cold Zone


  • Around poles
  • Largest wetlands of the world
  • Northern Alaska, Northern Canada, Greenland and northern Russia
  • Frozen desert
  • Denali national park
  • Permafrost – Permanently frozen sub soil
  • Snow in winter, beautiful landscape in summer
  • Bugyals in Himalayas
  • Mosses, lichens, Rhododendrons




  • largest biome
  • most stable biome
  • covers 75% of Earth’s surface
  • provides majority of Earth’s food and oxygen

Minerals of India



Ferrous – Iron, manganese

Non Ferrous – Cu, Bauxite

Non Metallic 

Fuel – Coal, Oil, petroleum

Others – mica, limestone, granite

Iron ore 

  • India has largest reserve in Asia
  • Haematite and magnetite
    • Northern Orissa – Rourkela steel plant (German collaboration)
    • Jharkand – Jamshedpur , Bokaro steel plant (Russian collaboration)
    • Chattisgarh – Bhilai steel plant (Russian collaboration)
    • Western WB – Durgapur steel plant (UK Collaboration)
    •  Goa


  • Iron Vs Steel

    • Iron is an element while steel is an alloy.
    • Steel is a derivative of iron.
    • Steel is actually made by mixing iron with carbon; hence it is a byproduct of iron
    • The iron that contains less than 2% of carbon is called steel whereas which contain more than 2% of carbon is known as pig iron


  • Raw material for smelting of iron and used for manufacturing ferro alloys
    • Orissa
    • Karnataka
    • Maharashtra


  • ore used in the manufacturing of Aluminium
  • Found in tertiary deposits
  • Associated with laterite rocks
    • Orissa – Kalahandi and Sambalpur
    • Jharkhand
    • Chattisgarh
    • MP


  • Making wires, electric motors, generators, transformers
  • Mixed with gold for strength
  • Alloy able, malleable, ductile
    • Jharkhand – Singhbhum
    • MP
    • RJ


  • Used in electrical and electronics industries
    • Jharkhand
    • Andhra – Nellore
    • Rajasthan


  • Generation of thermal power and smelting of iron ore
  • Bituminous type and non coking grade
    • Damodar Valley – Jharkhand Bengal belt
      • Raniganj
      • Jharia
      • Bokaro
    • TN – Brown coal/brown diamond/Lignite


  • Liquid gold
  • Automobiles, railways, aircrafts
  • Byproducts are used in soaps, wax, lubricants, vaseline etc..
    • Assam – Digboi
    • Gujarat
    • Mumbai high
    • KG Basin
    • Kaveri Basin
  • Oil needs to be refined
    • Field Based – Digboi, Assam
    • Market Based – Barauni, Bihar

World Economic Forum – WEF

  • It is a Swiss nonprofit foundation, based in Cologny, Geneva.
  • The forum was founded in 1971 by Klaus Schwab, a German-born business professor at the University of Geneva.
  • Recognized by the Swiss authorities as the international institution for public-private cooperation, its mission is cited as “committed to improving the state of the world by engaging business, political, academic, and other leaders of society to shape global, regional, and industry agendas”.
  • The Forum is best known for its annual winter meeting for five days in Davos, a mountain resort in Graubünden, in the eastern Alps region of Switzerland.
  • The meeting brings together some 2,500 top business leaders, international political leaders, selected intellectuals, and journalists for up to five days (winter) to discuss the most pressing issues facing the world.

Indian Meteorological Department – IMD

  • The Indian Meteorological Department (IMD), also referred to as the Met Department, is an agency of the Ministry of Earth Sciences of the Government of India.
  • It is the principal agency responsible for meteorological observations, weather forecasting and seismology.
  • It was established in 1875.
  • IMD is headquartered in New Delhi and operates hundreds of observation stations across India and Antarctica.
  • IMD is also one of the six Regional specialized Meteorological centres of the World Meteorological Organization.
  • It has the responsibility for forecasting, naming and distribution of warnings for tropical cyclones in the Northern Indian Ocean region, including the Malacca Straits, the Bay of Bengal, the Arabian Sea and the Persian Gulf.

PM National Relief Fund (PMNRF)

  • The fund consists entirely of public contributions and does not get any budgetary support.
  • The corpus of the fund is invested with banks in fixed deposits.
  • Disbursements are made with the approval of the Prime Minister.
  • PMNRF has not been constituted by the Parliament.
  • The fund is recognized as a Trust under the Income Tax Act and the same is managed by Prime Minister or multiple delegates for national causes.
  • Telegram:

  • PMNRF is exempt under Income Tax Act.
  • Prime Minister is the Chairman of PMNRF and is assisted by Officers/ Staff on honorary basis.
  • These contributions also qualify as CSR (corporate social responsibility) spend for companies, making it more attractive in terms of tax exemptions.
  • PMNRF accepts only voluntary donations by individuals and institutions.
  • Contributions flowing out of budgetary sources of Government or from the balance sheets of the public sector undertakings are not accepted.
  • At the time of natural calamity of devastating scale, Prime Minister, makes an appeal for donation to the fund.


Natural vegetation refers to a plant community that has been left undisturbed over a long time, so as to allow its individual species to adjust themselves to climate and soil conditions as fully as possible.

  • Himalayan heights are marked with temperate vegetation;
  • Western Ghats and the Andaman Nicobar Islands have tropical rain forests
  • Deltaic regions have tropical forests and mangroves;
  • Desert and semi desert areas of Rajasthan are known for cactii, a wide variety of bushes and thorny vegetation

On the basis of certain common features such as predominant vegetation type and climatic regions, Indian forests can be divided into the following groups


  • Tropical Evergreen and Semi-Evergreen forests
  • Tropical Deciduous forests
  • Tropical Thorn forests
  • Montane forests
  • Littoral and Swamp forests

Tropical Evergreen and Semi Evergreen Forests

  • Western slope of the Western Ghats, hills of the northeastern region and the Andaman and Nicobar Islands.
  • Warm and humid areas
  • Annual precipitation of over 200 cm
  • mean annual temperature above 22oC
  • Tropical evergreen forests are well stratified, with layers closer to the ground and are covered with shrubs and creepers, with short structured trees followed by tall variety of trees.
  • In these forests, trees reach great heights up to 60 m or above.
  • There is no definite time for trees to shed their leaves, flowering e.g. rosewood, mahogony, aini, ebony,fruition.

Semi evergreen forests

  • Found in the less rainy parts of these regions. Such forests have a mixture of evergreen and moist deciduous trees.
  • The under growing climbers provide an evergreen character to these forests.
  • Main species are white cedar, hollock and kail
  • British were aware of the economic value of the forests in India, hence, large scale exploitation of these forests was started. The structure of forests was also changed.
  • The oak forests in Garhwal and Kumaon were replaced by pine (chirs) which was needed to lay railway lines.
  • Forests were also cleared for introducing plantations of tea, rubber and coffee.
  • The British also used timber for construction activities as it acts as an insulator of heat.


Tropical Deciduous Forests

  • Most widespread forests in India (monsoon forests) – Rainfall- 70-200 cm.
  • Further divided into moist (200-100)and dry (70-100) deciduous.
  • Moist northeastern states along the foothills of Himalayas, eastern slopes of the Western Ghats and Orissa.
  • Teak, sal, shisham, hurra, mahua,amla, semul, kusum, and sandalwood
  • Dry Rainier areas of the Peninsula and the plains of Uttar Pradesh and Bihar.
  • In the higher rainfall regions of the Peninsular plateau and the northern Indian plain, these forests have a parkland landscape with open stretches in which teak and other trees interspersed with patches of grass are common.
  • As the dry season begins, the trees shed their leaves completely and the forest appears like a vast grassland with naked trees all around.
  • Tendu, palas, amaltas, bel, khair, axlewood, etc.
  • In the western and southern part of Rajasthan, vegetation cover is very scanty due to low rainfall and overgrazing.

Tropical Thorn Forests

  •  Rainfall less than 50 cm
  • Grasses and shrubs
  •  Semi-arid areas of south west Punjab, Haryana, Rajasthan, Gujarat, Madhya Pradesh and Uttar Pradesh.
  • Plants remain leafless for most part of the year and give an expression of scrub vegetation.
  • babool, ber, and wild date palm, khair, neem, khejri, palas, etc.
  • Tussocky grass grows upto a height of 2 m as the under growth.

Montane Forests –

  • Decrease in temperature with increasing altitude leads to a corresponding change in natural vegetation
  • Types- northern mountain forests and the southern mountain forests.
  • Himalayan ranges show a succession of vegetation from the tropical to the tundra, which change in with the altitude.

Deciduous forests are found in the foothills of the Himalayas.

  • 1,000-2,000 m – wet temperate type of forests
  • 1,500-1,750 m- pine forests, Chir Pine ,Deodar – construction activity. chinar and walnut –Kashmir handicrafts
  • 2,225-3,048 m – Blue pine and spruce
  • 3,000-4,000 m – Silver firs, junipers, pines, birch and rhododendrons


Littoral and Swamp Forests

  • About 70 per cent of this comprises areas under paddy cultivation.
  • Total area of wet land is 3.9 million hectares.
  • Two sites — Chilika Lake (Orissa) and Keoladeo National Park (Bharatpur) are protected as water-fowl habitats under the Convention of Wetlands of International Importance (Ramsar Convention).


The country’s wetlands have been grouped into eight categories-

  1. The reservoirs of the Deccan Plateau in the south together with the lagoons and other wetlands of the southern west coast;
  2. The vast saline expanses of Rajasthan, Gujarat and the Gulf of Kachchh;
  3. Freshwater lakes and reservoirs from Gujarat eastwards through Rajasthan (Keoladeo National Park) and Madhya Pradesh;
  4. The delta wetlands and lagoons of India’s east coast (Chilika Lake);
  5. The freshwater marshes of the Gangetic Plain; (vi) the floodplains of the Brahmaputra;
  6. The marshes and swamps in the hills of northeast India and the Himalayan foothills;
  7. The lakes and rivers of the montane region of Kashmir and Ladakh;
  8. The mangrove forest and other wetlands of the island arcs of the Andaman and Nicobar Islands.


  • Mangroves grow along the coasts in the salt marshes, tidal creeks, mud flats and estuaries.
  • Crisscrossed by creeks of stagnant water and tidal flows, these forests give shelter to a wide variety of birds.
  • In India, the mangrove forests spread over 6,740 sq. km which is 7 per cent of the world’s mangrove forests.
  • Andaman and Nicobar Islands and the Sunderbans of West Bengal, Mahanadi, the Godavari and the Krishna deltas


Miscellaneous Points:-

  • Transhumance tribes – Gujjars, the Bakarwals, the Bhotiyas and the Gaddis.
  • At higher altitudes, mosses and lichens form part of the tundra vegetation.
  • Southern slopes of the Himalayas carry a thicker vegetation cover because of relatively higher precipitation than the drier north-facing slopes.
  • The southern mountain forests include the forests found in three distinct areas of Peninsular India viz; the Western Ghats, the Vindhyas and the Nilgiris.
  • Temperate forests are called Sholas in the Nilgiris, Anaimalai and Palani hills.
    Forest– magnolia, laurel, cinchona and wattle.

Monsoon and factors determining the Climate of India


  • There are variations in weather conditions during different seasons.  These changes occur due to the changes in the elements of weather (temperature, pressure, wind direction and velocity, humidity and precipitation, etc.).
  • Weather is the momentary state of the atmosphere while climate refers to the average of the weather conditions over a longer period of time.
  • Monsoon connotes the climate associated with seasonal reversal in the direction of winds.
  • India has hot monsoonal climate which is the prevalent climate in south and southeast Asia.
  • Monsoon regime emphasizes the unity of India with the rest of Southeast Asian region.
  • The climate of India has many regional variations expressed in the pattern of winds, temperature and rainfall, rhythm of seasons and the degree of wetness or dryness. These regional diversities may be described as sub-types of monsoon climate.
  • There are seasonal variations in temperature from place to place and from region to region in India.
  • Most parts of the country get rainfall during June-September, but on the coastal areas of Tamil Nadu, it rains in the beginning of the winter season.


Factors related to Location and Relief


  • Tropic of Cancer passes through the central part of India in east-west direction. Thus, northern part of the India lies in sub-tropical and temperate zone and the part lying south of the Tropic of Cancer falls in the tropical zone.

The Himalayan Mountains

  • The lofty Himalayas in the north along with its extensions act as an effective climatic divide.
  • The towering mountain chain provides an invincible shield to protect the subcontinent from the cold northern winds.
  • These cold and chilly winds originate near the Arctic circle and blow across central and eastern Asia.
  • The Himalayas also trap the monsoon winds, forcing them to shed their moisture within the subcontinent.

Distribution of Land and Water

  • Indian Ocean on three sides in the south and girdled by a high and continuous mountain-wall in the north.
  • This differential heating of land and sea creates different air pressure zones in different seasons in and around the Indian subcontinent.
  • Difference in air pressure causes reversal in the direction of monsoon winds.

Distance from the Sea

  • Areas in the interior of India are far away from the moderating influence of the sea. Such areas have extremes of climate


  • Temperature decreases with height.
  • Due to thin air, places in the mountains are cooler than places on the plains.


  • Physiography or relief of India also affects the temperature, air pressure, direction and speed of wind and the amount and distribution of rainfall e.g. windward sides of Western Ghats and Assam receive high rainfall during June-September whereas the southern plateau remains dry due to its leeward situation along the Western Ghats.

Factors Related to Air Pressure and Wind

  1.  Distribution of air pressure and winds on the surface of the earth.
  2.  Upper air circulation caused by factors controlling global weather and the inflow of different air masses and jet streams.
  3.  Inflow of western cyclones generally known as disturbances during the winter season.
  4. Tropical depressions during the south-west monsoon period into India, creating weather conditions favorable to rainfall

Mechanism of Weather in the Winter Season

Surface Pressure and Winds

  •  In winter months, the weather conditions over India are generally influenced by the distribution of pressure in Central and Western Asia.
  • The surface winds blowing out of the high pressure center over Central Asia reach India in the form of a dry continental air mass.
  • These continental winds come in contact with trade winds over northwestern India.
  • Result – whole of the northwestern and northern India up to the middle Ganga valley comes under the influence of dry northwestern winds.

Jet Stream and Upper Air Circulation

  • Higher up in the lower troposphere, about 3 km above the surface of the earth, a different pattern of air circulation is observed.
  • The variations in the atmospheric pressure closer to the surface of the earth have no role to play in the making of upper air circulation.
  • All of Western and Central Asia remains under the influence of westerly winds along the altitude of 9-13 km from west to east.
  • These winds blow across the Asian continent at latitudes north of the Himalayas roughly parallel to the Tibetan highlands. These are known as jet streams
  • Tibetan highlands act as a barrier in the path of these jet streams. As a result, jet streams get bifurcated.
  • One of its branches blows to the north of the Tibetan highlands, while the southern branch blows in an eastward direction, south of the Himalayas (February mean position at 25°N)
  • Southern branch of the jet stream exercises an important influence on the winter weather in India.

Western Cyclonic Disturbance and Tropical Cyclones

  • Western cyclonic disturbances which enter the Indian subcontinent from the west and the northwest during the winter months originate over the Mediterranean Sea and are brought into India by the westerly jet stream.
  • An increase in the prevailing night temperature generally indicates an advance in the arrival of these cyclones disturbances.
  • Tropical cyclones originate over the Bay of Bengal and the Indian Ocean.
  • These tropical cyclones have very high wind velocity and heavy rainfall and hit the Tamil Nadu, Andhra Pradesh and Orissa coast.
  • Very destructive due to high wind velocity and torrential rain that accompanies it.

Mechanism of Weather in the Summer Season

Surface Pressure and Winds

  • As the summer sets in and the sun shifts northwards, the wind circulation over the subcontinent undergoes a complete reversal at both, the lower as well as the upper levels.
  • By the middle of July, the low pressure belt nearer the surface [termed as Inter Tropical Convergence Zone (ITCZ)] shifts northwards, roughly parallel to the Himalayas between 20° N and 25° N.
  • By this time, the westerly jet stream withdraws from the Indian region.
  • ITCZ and Westerly Jet Stream
  • Found interrelationship between the northward shift of the equatorial trough (ITCZ) and the withdrawal of the westerly jet stream from over the North Indian Plain. It is generally believed that there is a cause and effect relationship between the two.

Southwest monsoon

  •  ITCZ being a zone of low pressure attracts inflow of winds from different directions.
  • The maritime tropical airmass (mT) from the southern hemisphere, after crossing the equator, rushes to the low pressure area in the general southwesterly direction. It is this moist air current which is popularly known as the southwest monsoon

Jet Streams and Upper Air Circulation

  •  The easterly jet stream sets in along 15°N latitude only after the western jet stream has withdrawn itself from the region. This easterly jet stream is held responsible for the burst of the monsoon in India.
  • The easterlies normally do not extend to the north of 30o N latitude in the upper atmosphere.

Inter Tropical Convergence Zone (ITCZ)

  • Inter Tropical Convergence Zone (ITCZ) is a low pressure zone located at the equator where trade winds converge, and so, it is a zone where air tends to ascend.
  • In July, the ITCZ is located around 20°N-25°N latitudes (over the Gangetic plain), sometimes called the monsoon trough. This monsoon trough encourages the development of  thermal low over north and northwest India.
  • Due to the shift of ITCZ, the trade winds of the southern hemisphere cross the equator between 40° and 60°E longitudes and start blowing from southwest to northeast due to the Coriolis force.
  • It becomes southwest monsoon. In winter, the ITCZ moves southward, and so the reversal of winds from northeast to south and southwest, takes place. They are called northeast monsoons.