‘Anti-hail guns’, developed indigenously, will be tested by the Himachal Pradesh government to help out horticulturists who face crop damage due to hailstorms.
What are anti-hail guns?
An anti-hail gun is a machine that generates shock waves to disrupt the growth of hailstones in clouds.
Who has developed these anti-hail guns?
These anti-hail guns have been developed indigenously by IIT Bombay along with Dr Y S Parmar University of Horticulture and Forestry at Nauni (Solan). They are likely to be much cheaper than the imported ones.
How do anti-hail guns prevent a hail storm?
Anti-hail gun comprises a tall, fixed structure somewhat resembling an inverted tower, several meters high with a long and narrow cone opening towards the sky.
The gun is “fired” by feeding an explosive mixture of acetylene gas & air into its lower chamber. This releases a shock wave (waves that travel faster than the speed of sound, such as those produced by supersonic aircraft).
These shock waves supposedly stop water droplets in clouds from turning into hailstones, so that they fall simply as raindrops.
What are Hailstorms?
A hailstorm is an unusual weather phenomenon in which balls of ice, called hail, fall from the sky. The ice balls are nothing more than solid precipitation that forms under certain conditions.
How are Hails formed?
Hails are formed by cumulonimbus clouds which are generally large and dark and may cause thunder and lightning.
In such clouds, winds can blow up the water droplets to heights where they freeze into ice.
The frozen droplets begin to fall but are soon pushed back up by the winds and more droplets freeze onto them, resulting in multiple layers of ice on the hailstones.
This fall and rise are repeated several times, till the hailstones become too heavy and fall down.
Previous such anti-hail guns used in Himachal:
In 2010, the Himachal Pradesh government had imported three anti-hail guns from the United States. They were installed in the apple-growing belt of Shimla where hailstorms in summer cause severe damage to the fruit every year.
Two of the machines are currently functional, while the third one was rejected by local residents.
State horticulture department officials maintain that since the installation of the guns, hail has occurred very few times in the villages.
Synopsis – IMD recently updated the status of the monsoon and predicted a normal monsoon this year. IMD has adopted a new Dynamical Forecast Model. It will allow farmers, government officials, disaster managers, and other stakeholders to better prepare for their activities.
Further, the southwest monsoon in 2021, which will begin in June, is forecast to be regular, with 98 percent of the Long Period Average rainfall (LPA).
During the monsoon season, weak El Nino conditions are likely to prevail, with severity decreasing as the season progresses.
Rainfall between 96 and 104 percent of the Long Period Average [LPA] is considered normal.
What is the importance of the new Dynamical monsoon Model?
New Dynamical Monsoon Forecast Model uses the evolving weather patterns to predict monsoon. It is not like the traditional method in which the forecast was based on a fixed set of meteorological variables.
Also, dynamic models are useful for predicting rainfall over smaller spatial and temporal scales. It is not possible with IMD’s previous statistical forecasting method.
IMD will forecast rainfall for June and September, using this model. It was previously difficult to predict due to the monsoon’s arrival and departure.
There will also be forecasts for the monsoon core zone [MCZ]. It represents most of the rain-fed agriculture regions in the country.
Why is it important to correctly forecast rainfall?
For disaster preparedness – Accurate forecasts will aid in the implementation of preventative measures, the reduction of vulnerabilities. It can also prevent extreme events from turning into disasters.
For example- Preparation of a heat plan/forest fires plan in case of hot summer.
For agriculture purposes – Farmers can decide on sowing time based on local conditions. Also, they can decide the type of crop that is best suited to the conditions, using accurate forecasting.
For Government planning- the Centre and states can prepare better joint plans with respect to agriculture; such as drought action plan, MSP and buffer creation. It can better use and optimize government schemes
For several business and service sector industries which need weather products.
Way forward-
IMD’s move from a statistical to Dynamical Forecast model will improve the accuracy of its forecast, so that farmers, policymakers, local administration, scientists & aid organizations can make most of it.
What is the News? A new study shows the impacts of desert dust coming from the West, Central, and East Asia in the Indian Summer Monsoon.
Impacts of Desert Dust Particles on Indian Summer Monsoon:
Strong winds carry the dust particles from the Middle East into the atmosphere. Dust particles absorb solar radiation and become extremely hot.
This causes the atmosphere to heat. The heat decreases the air pressure and changes wind circulation patterns. Further, it increases the moisture transport capacity of air and increases precipitation and rainfall.
This phenomenon is termed an “elevated heat pump”. It is responsible for driving moisture from the sea to the Indian subcontinent.
Positive Feedback Loop:
Positive Feedback Loop is a loop where the result of a reaction leads to an enhancement of that very reaction.
In this case, too, a positive feedback loop plays a role when the dust particles from the Middle East boost the power of Indian monsoons.
In turn, the monsoons increase the winds in the Middle East and subsequently produce more dust aerosols.
Role of Iranian Plateau on Indian Summer Monsoon:
Iranian Plateau also influences the Indian Summer Monsoon. The hot air over the Iranian Plateau can heat the atmosphere over the plateau. It further strengthens the circulation over the deserts of the Arabian Peninsula and increases dust emission from the Middle East [West Asia].
Influence of Aerosols on Indian Summer Monsoon:
Aerosol is a suspension of fine solid particles or liquid droplets in air or another gas. Aerosols can be natural or anthropogenic:
Examples of natural aerosols are fog, mist, dust, forest exudates, and geyser steam.
Examples of anthropogenic aerosols are particulate air pollutants and smoke.
Some studies have found that anthropogenic aerosols emitted from the Indian subcontinent can decrease summer monsoon precipitation.
While other studies have found that absorbing aerosols such as dust can strengthen the monsoon circulation.
However, in this study, it was found that anthropogenic aerosols can strengthen Indian summer monsoon rainfall.
Influence of Dust Particles across the Globe: Dust Particles from deserts across the globe play important role 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.
The small deserts in the southwest United States are known to influence the North African monsoon.
According to a study, Mawsynram(Meghalaya) become the wettest place in the World. It has replaced Cherrapunji(Meghalaya) from the top spot. Mawsynram receives over 10,000 MM of rain in a year.
About the study:
The study looked at the rainfall pattern of the past 119 years (period of 1901–2019). It found a decreasing rainfall trend at Cherrapunji and nearby areas.
The 1973–2019 period shows a decrease of about 0.42 mm per decade in rainfall. This trend was statistically significant at seven stations (Agartala, Cherrapunji, Guwahati, Kailashahar, Pasighat, Shillong and Silchar).
What was the need for this study?
Northeast India is highly sensitive to changes in regional and global climate. The first signs of the effect of climate change will be evident in extreme cases such as the rainfall at Cherrapunji.
Northeast India also has the highest vegetation cover in India. It includes 18 biodiversity hotspots of the world,
Thus, it is important in terms of its greenery and climate-change sensitivity.
Reasons for decreasing trend of rainfall:
Changes in Temperature: The changes in the Indian Ocean temperature have a huge effect on the rainfall in the NorthEast region.
Reduction in Vegetation Area: Satellite data analysis shows a reduction in the vegetation area in northeast India. Lesser vegetation results in changing rainfall patterns.
Increase in Cropland Area and Deforestation: Jhum cultivation or shifting cultivation in the region has contributed to deforestation and an increase in cropland area.
Jhum Cultivation:
Jhum Cultivation also known as shifting cultivation. It is a slash-and-burn agricultural practice that is widely practised among the indigenous communities of Northeast India.
Under this cultivation, the farmers grow the crops by first clearing the land of trees and vegetation and burning them thereafter. The burnt soil contains potash which increases the nutrient content of the soil.
The world’s largest existing iceberg has been found in Antarctica. It has been named as A-76 by scientists.
About A-76 Iceberg:
A-76 Iceber has been spotted in the satellite images captured by the European Space Agency’s Copernicus Sentinel-1 mission.
Formation: The iceberg has been formed after it broke away from Antarctica’s Ronne Ice Shelf. It is now floating freely in the Weddell Sea, a large bay in western Antarctica.
Features: The iceberg is shaped like a giant ironing board. It is measured around 170 km in length and 25 km in width. This makes the A-76 to become slightly larger than the Spanish island of Majorca.
The Largest Existing Iceberg: A-76 is now designated as the largest existing iceberg on the planet. It surpassed the A-23A (It is also floating in the Weddell Sea).
Significance: Once this iceberg melts, it will not lead to a sea-level rise because it was part of a floating ice shelf. It is just like a melting ice cube doesn’t increase the level of the water in the glass.
This makes the icebergs like this different from glaciers or ice sheets. Glaciers or ice sheets found on land, and they raise global sea levels when they break off into the ocean and melt.
Indonesia’s Mount Sinabung has erupted releasing a massive column of volcanic ash and smoke up to 3,000 metres(3 km) into the sky.
About Mount Sinabung:
Mount Sinabung is located in North Sumatra in Indonesia. It is among more than 130 active volcanoes in Indonesia. (Indonesia is prone to seismic upheaval due to its location on the Pacific’s Ring of Fire).
The volcano was dormant for 400 years before exploding in 2010. It exploded again in 2014 and 2016.
About Ring of Fire:
The Ring of Fire also referred to as the Circum-Pacific Belt is a path along the Pacific Ocean. Its characteristics include active volcanoes and frequent earthquakes.
Boundaries: It traces boundaries between several tectonic plates including Pacific, Cocos, Indian-Australian, Nazca, North American and Philippine Plates.
Significance:
75% of Earth’s volcanoes i.e. more than 450 volcanoes are located along the Ring of Fire.
90% of Earth’s earthquakes occur along its path.
The abundance of volcanoes and earthquakes along the Ring of Fire is due to the frequent movement of tectonic plates in this area.
What is Volcano?
A volcano is an eruption in the earth’s crust through which the lava, volcanic ash and gases escape to release pressure.
Why Volcanic Eruption takes place?
Magma is a thick flowing substance. Its formation happens during the melting of Earth’s crust and mantle.
Volcanic eruption takes place when magma rises to the surface.
As magma is lighter than rock, it is able to rise through vents and fissures on the surface of the earth. After the eruption, the magma is called lava.
Types of Volcanoes: Volcanoes are classified as active, dormant, or extinct:
Active volcanoes have a recent history of eruptions. They are likely to erupt again.
Dormant volcanoes have not erupted for a very long time but may erupt at a future time.
Extinct volcanoes are not expected to erupt in the future.
Risk From Volcanic Eruptions:
The most common cause of death from a volcano is suffocation. People with respiratory conditions such as asthma and other chronic lung diseases are susceptible to suffocation.
People living close to the volcano or in low-lying downwind areas are also at higher risk in case of an explosion. As the ash may be coarse-grained and abrasive, even small particles can scratch the surface of the eyes.
Further, volcanic eruptions can result in additional threats to health such as floods, mudslides, power outages, drinking water contamination and wildfires.
What is the News? Researchers at Sweden’s University of Gothenburg releases a new finding related to the melting of the Thwaites Glacier. They found that the melting was worse than previously thought.
About Thwaites Glacier:
Source – BBC
Thwaites Glacier is a 120 km wide, fast-moving glacier located in Antarctica.
Size: Because of its size (1.9 lakh square km), it contains enough water to raise the world sea level by more than half a meter.
Melting: Its melting already contributes 4% to global sea-level rise each year. It is estimated that it would collapse into the sea in 200-900 years.
Studies have found the amount of ice flowing out of it has nearly doubled over the past 30 years.
Significance: Thwaites Glacier is important for Antarctica as it slows the ice behind it, from freely flowing into the ocean. However, because of the risk it faces — and poses — Thwaites is often called the Doomsday Glacier.
About the Study:
Gothenburg study used an uncrewed submarine called “Ran” to go under the Thwaites’ glacier front to make observations.
The researchers measured the strength, temperature, salinity, and oxygen content of the ocean currents that go under the glacier.
Findings: The study found that warm water is approaching the glacier from all sides. It is impacting the locations where the ice connects to the seabed and where the ice sheet finds stability. This has the potential to make things worse for Thwaites, whose ice shelf is already retreating.
Earlier Studies:
Cavity in the Glacier: A 2019 study had discovered a fast-growing cavity in the Thwaites’ glacier. It’s size was roughly two-thirds of the area of Manhattan.
A cavity is created by relatively warm ocean water melting the ice shelf. As the glacier becomes exposed to more warm-water currents, the ice will probably melt faster.
Detection of Warm Water at Grounding Line: In 2020, researchers from New York University(NYU) detected warm water at Thwaites’ “grounding zone” or “grounding line”.
The Grounding Line is the place below a glacier at which the ice transitions between resting fully on bedrock and floating on the ocean as an ice shelf. The location of the line is a pointer to the rate of retreat of a glacier.
When glaciers melt and lose weight, they float off the land where they used to be situated. When this happens, the grounding line retreats. That exposes more of a glacier’s underside to seawater, increasing the likelihood it will melt faster.
This results in the glacier speeding up, stretching out, and thinning, causing the grounding line to retreat ever further.
Parts of Uttarakhand witnessed massive flooding due to Glacial Lake outburst.
What is Glacial Lake Outburst Floods(GLOF)?
It is a type of outburst flood. It occurs when water dammed by a glacier is released. In other words, it’s an outburst that happens when a dam containing a glacial lake fails.
Note: An event similar to a GLOF, where a body of water contained by a glacier melts or overflows the glacier is called a jökulhlaup.
How does GLOF happen?
Retreating glaciers, like several in the Himalayas, usually result in the formation of lakes at their tips, called proglacial lakes. It is often bound only by sediments and boulders.
If the boundaries of these lakes are breached, it can lead to large amounts of water rushing down to nearby streams and rivers. It gathers momentum on the way by picking up sediments, rocks, and other material, and resulting in flooding downstream.
Features of GLOF: The three main features are:
They involve sudden (and sometimes cyclic) releases of water.
They tend to be rapid events, lasting hours to days.
Furthermore, they result in large downstream river discharges (which often increase by an order of magnitude).
Causes behind GLOFs
The boundaries of glacial lakes breach due to multiple reasons. Like,
A buildup of water pressure or structural weakness of boundary due to an increase in the flow of water.
An earthquake (Tectonic) or cryoseism (non-tectonic seismic event of the glacial cryosphere) can also cause GLOF. During this, the boundary of the glacial lake will collapse suddenly and release the water in the glacial lake.
An avalanche of rock or heavy snow: During this, the water in the glacial lake might be displaced by the avalanche.
Volcanic eruptions under the ice can also cause GLOF. These volcanic eruptions might displace the boundary or increase the pressure on glacial lake or both.
Heavy rainfall/melting of snow: This can lead to massive displacement of water in a glacial lake.
Long-term dam degradation can also induce GLOF.
Other reasons such as the collapse of an adjacent glacial lake, etc.
What are Glaciers?
Glaciers are made up of fallen snow. It compresses into large, thickened ice masses over a period of time. They are formed when snow remains in one location long enough to transform into ice.
Where are Glaciers found? Glaciers are found on every continent except Australia. Some are hundreds of thousands of years old. A large cluster of glaciers are in the Himalayas, which are part of India’s long northern border.
The Supreme Court of India has refused to stop the demolition of over 10,000 settlements encroaching on forests in the Aravalli range in Haryana’s Faridabad district.
What was the case about?
Public interest litigation was filed in the Supreme Court seeking a stay on the demolition of the settlements.
The petitioners had also asked the court for more time to produce documents to claim rehabilitation.
What did the Supreme Court say?
The Supreme Court has refused to stop the demolition. It said that the residents had enough time to prove their claims in accordance with a notification issued by Haryana in 2020.
The court also said the onus was on the State to rehabilitate the residents in compliance with a 2003 scheme. Hence, demolition should continue.
Aravalli Range is the oldest mountain range in India and one of the oldest mountain systems in the world.
The Aravalli range is spread across the states of Gujarat, Rajasthan, Haryana and Delhi.
History:
The natural history of the Aravalli Range dates back to times when the Indian Plate was separated from the Eurasian Plate by an ocean.
Mining of copper and other metals in the Aravalli range dates back to at least the 5th century BCE, based on carbon dating.
Rivers: The three major rivers and their tributaries flow from the Aravalli. Namely Banas and Sahibi rivers which are tributaries of Yamuna, as well as Luni River which flows into the Rann of Kutch.
Highest Peak: Guru Shikhar Peak on Mount Abu is the highest peak in the Aravalli Range (1,722 m).
An Earthquake of 6.4 magnitude hit Assam on April 28th, 2021. It caused sufficient damage to buildings and property but fortunately, no fatalities were reported. The northeastern region has a peculiar record of experiencing earthquakes at regular intervals due to its unique geographical location. The state of Assam itself witnessed two great earthquakes (Magnitude >8) in 1897 and 1950.
In this article, we will try to ascertain the reasons behind the occurrence of earthquakes, their brutal impacts, and the vulnerability of the northeast region that converts it into a disaster. Further, we will try to find out what rational measures should be taken for developing robust earthquake resilience.
How does an earthquake occur?
Firstly, an earthquake occurs when there is a sudden release of energy in the Earth’s lithosphere that creates seismic waves.
Secondly, the release of energy occurs along a fault. A fault is a sharp break in the crustal rocks.
Thirdly, rocks along a fault tend to move in opposite directions. As the overlying rock strata press them, the friction locks them together. However, their tendency to move apart at some point in time overcomes the friction.
Fourthly, as a result, the blocks get deformed, and eventually, they slide past one another abruptly. This causes a release of energy, and the energy waves travel in all directions.
Focus: The point where the energy is released is called the focus of an earthquake. It is also called the hypocentre.
Epicentre: The energy waves travelling in different directions reach the surface. The point on the surface, nearest to the focus, is called the epicentre.
Current Scenario
Recently an earthquake of magnitude 6.4 on the Richter scale hit Assam. It occurred near Dhekiajuli in the Sonitpur district of Assam, 80 kilometres northeast of Guwahati.
Following the main tremors, six aftershocks (of magnitude ranging from 3.2 to 4.7) also occurred within two-and-a-half hours.
The National Centre for Seismology (NCS) recently mentioned that these tremors were attributed to the Kopili Fault Zone.
About Kopili Fault Zone
It is a 300-km northwest-southeast trending fault. It extends from the western part of Manipur to the tri-junction of Bhutan, Arunachal Pradesh, and Assam.
The zone has witnessed many seismic activities in the past. This includes the 1869 earthquake (7.8 magnitude) and the 1943 earthquake (7.3 magnitude).
The zone is located closer to Himalayan Frontal Thrust (HFT).
It is a geological fault along the boundary of the Indian and Eurasian tectonic plates.
Source: ISR
History of Earthquakes in the Northeast Region
The North-Eastern part of the country continues to experience moderate to large earthquakes at frequent intervals. This includes the two great earthquakes -1897 Shillong (Magnitude – 8.7) and 1950 Assam-Tibet (Magnitude – 8.6).
On average, the region experiences an earthquake with a magnitude greater than 6.0 every year.
Vulnerability of Northeast Region to Earthquake
High Seismicity Level: Northeast is located in the highest seismological zone. The Kopili Fault Zone is a seismically active area, so it falls into the highest Seismic Hazard Zone V. It is associated with collisional tectonics because the Indian Plate is subducting beneath the Eurasian Plate.
Nature of Soil: Kopili fault zone and its neighbouring areas are characterized by alluvial soils. These alluvial soil have a higher potential of trapping seismic waves. Thus making the region the most earthquake-prone zone in North East India.
Terrain: The region has a significant amount of mountainous terrain that demands explosions for building a tunnel, road, etc. infrastructure. This enhances the probability of earthquakes.
Untapped Potential: The region has not seen robust development like the rest of India. Thus, a greater number of development projects like mining, dam construction, etc. in the region are under planning. It may enhance earthquake probability in the future.
High-technology equipment and tools: There has been an increase in the use of high-technology equipment and tools in the manufacturing and service industries. This has made them susceptible to disruption even by moderate ground shaking.
Unscientific Buildings: Many buildings in the cities of Shillong, Gangtok etc. are constructed on the sloping ground. That too by excavating some part of the hill.
The open ground storey, heavy overhangs, heavy rooftops, and irregular plan shapes are common in buildings that make them seismically more vulnerable.
Policy gap: There is a considerable knowledge and policy gap regarding earthquakes in the Northeast. Even a good knowledge about the Kopili fault did not result in disaster reduction policies.
Earthquake Zonation in India
India has been divided into four seismic zones (II, III, IV, and V) based on scientific inputs relating to seismicity, earthquakes that occurred in the past and the tectonic setup of the region.
Source: National Institute of Disaster Management
General reasons behind the occurrence of earthquakes
Firstly, Tectonic Activities: Sliding of rocks along a fault plane can cause sudden shaking of the ground, resulting in an earthquake.
Secondly, Volcanic activities: A special class of tectonic earthquakes is sometimes recognized as a volcanic earthquake. However, these are confined to areas of active volcanoes.
Thirdly, Human-Induced: Minor earthquakes and tremors that are caused by human activity like mining, large-scale petroleum extraction, artificial lakes (reservoirs), nuclear tests, etc.
Collapse Earthquakes: In the areas of intense mining activity, sometimes the roofs of underground mines collapse causing minor tremors.
Explosion Earthquakes: Ground shaking may also occur due to the explosion of chemical or nuclear devices. Such tremors are called explosion earthquakes.
Reservoir-induced: The earthquakes that occur in the areas of large reservoirs are referred to as reservoir-induced earthquakes.
Impact of Earthquake
Loss of Human Lives: The earthquakeshave eaten up thousands of precious human lives across the world.
Around 1,542 deaths occurred in Assam during the 1897 Great Earthquake.
Infrastructural Damage: Several houses and buildings were damaged after an earthquake of magnitude 6.4 hit Assam.
Similarly, the great Assam earthquake (1897) reduced all masonry buildings to debris within a region of northeastern India. This is roughly the size of England.
Initiating another disaster: The 1950 Assam earthquake caused huge landslides. These landslides in turn blocked many rivers in the mountainous region and caused floods.
Land Degradation: The recent Kolipi Fault zone earthquake caused cracks in a paddy field situated in Tatkal Basti village of Misamari, a town on the Assam-Arunachal Pradesh foothills.
Economic Losses: A significant amount is spent on reconstructing the lost infrastructure, rehabilitation of masses, and providing relief support to the impacted people.
Suggestions
Firstly, the government has to fix the knowledge and policy gap regarding earthquakes in North East India.
Secondly, the government has to build an effective Earthquake mitigation plan. This would involve constructing resilient infrastructure among other things.
For instance, the Delhi Metro pillar can easily withstand an earthquake of magnitude 9.
Thirdly, an integrated disaster management plan should be developed for the North East. This plan will help in tackling these types of high-intensity earthquakes.
Fourthly, due adherence to Environmental impact assessment must be observed before initiating mining or dam construction.
Fifthly, more funding should be given to Earthquake planning and mitigating agencies to improve disaster management potential.
For instance, the National Centre for Seismology has developed ‘India Quake’. An App for Earthquake Parameter Dissemination
Conclusion
Being in the seismic zone 5, earthquakes are bound to occur in the northeast region. The government is incapable of stopping their occurrence. Although it can definitely curtail their adverse impact by developing robust resilience in consonance with Sendai Framework for Disaster Risk Reduction 2015-2030.
The National Centre for Seismology (NCS) has said that the tremors in Assam can be attributed to the Kopili Fault Zone. The fault zone is located closer to Himalayan Frontal Thrust (HFT).
About the tremors in Assam:
Recently an earthquake of magnitude 6.4 on the Richter scale hit Assam. Following the main tremors, six aftershocks (of magnitude ranging from 3.2 to 4.7) also occurred within two-and-a-half hours. The NCS recently mentioned that these tremors were attributed to the Kopili Fault Zone.
Kopili Fault Zone:
The Kopili fault zone is a 300-km northwest-southeast trending fault. It is extending from the western part of Manipur to the tri-junction of Bhutan, Arunachal Pradesh and Assam.
A fault is a fracture or zone of fractures between two blocks of rock. Faults allow the blocks to move relative to each other. This movement may occur rapidly, in the form of an earthquake. Or it may occur slowly, in the form of creep.
Seismically Active: This zone is a seismically active area, so it falls into the highest Seismic Hazard Zone V.
The zone is associated with collisional tectonics because of the Indian Plate subducting beneath the Eurasian Plate.
Subduction is a geological process in which one crustal plate is forced below the edge of another.
Characteristics: Kopili fault zone and its neighbouring areas are characterised by alluvial soils. These alluvial soil have a higher potential of trapping seismic waves. Thus making the region the most earthquake-prone zone in North East India.
Earlier Earthquakes: Kopili fault zone has witnessed many seismic activities in the past. This includes the 1869 earthquake (7.8 magnitude) and the 1943 earthquake (7.3 magnitude).
About Himalayan Frontal Thrust (HFT):
It is also known as the Main Frontal Thrust (MFT). It is a geological fault along the boundary of the Indian and Eurasian tectonic plates.
Way Forward:
Firstly, the government has to fix the knowledge and policy gap regarding earthquakes in North East India.
Secondly, the government has to build an effective Earthquake mitigation plan.
Thirdly, an integrated disaster management plan should be developed for the North East. This plan will help in tackling these types of high-intensity earthquakes.
The Prime Minister through a tweet asked everyone to visit a tulip garden in Jammu and Kashmir. The garden is located at the foothills of the Zabarwan range.
About the Tulip garden
The tulip garden is located at the foothills of the Zabarwan range. It is Asia’s largest tulip garden, spreading over an area of about 30 hectares.
This garden is home to more than 64 varieties of tulips in bloom. Further, it was started in 2007 to boost floriculture and tourism in Kashmir Valley.
About Zabarwan Range:
It is a short sub-mountain range between Pir Panjal and Great Himalayan Range. It is located in the central part of the Kashmir Valley.
The Highest Peak: The highest peak of this range is Mahadev Peak at 13,013 feet (3,966 m). It forms the distant background of the eastern mountain wall.
Temple: The Shankaracharya Temple is built on the edge of the central part of the Zabarwan Range.
Significance: On the northern slopes of the central part of the range there are three Mughal gardens built by Emperor Shah Jahan. These include Chashma Shahi, Nishat Bagh, and Shalimar Garden alongside the Pari Mahal.
Wildlife: The Zabarwan mountain range possesses great Himalayan features with rich wildlife. The Dachigam National Park is the main feature of the range.
The Dachigam National Park holds the last viable population of Kashmir stag (Hangul). Further, the National Park also has the largest population of black bear in Asia.
Sardar Sarovar Dam usually has no water for irrigation during summers. However, for the first time in history, the dam has been filled with Narmada water.
About Sardar Sarovar Dam:
Sardar Sarovar Narmada Dam is a terminal dam built on the Narmada river at Kevadia in Gujarat’s Narmada district. The dam is called the ‘lifeline of Gujarat’.
Indian States: The four Indian states namely Gujarat, Madhya Pradesh, Maharashtra and Rajasthan receive water and electricity supply from the dam. They share the water as per the ratio stipulated by the 1979 award of the Narmada Water Dispute Tribunal.
Construction of the Dam:
The foundation stone of the dam was laid out by Prime Minister Jawaharlal Nehru in 1961.
However, the construction of the dam was stopped by the Supreme Court of India in 1995 over concerns of displacement of people.
In 2000–01, the project was again revived but with a lower height under directions from SC. But its height was later again increased to 139 metres in 2017.
The dam was then inaugurated in 2017 by the present Prime minister.
Water Management Initiatives that helped to harness water for the Dam:
During the monsoon, the Sardar Sarovar Dam operation is well synchronised with the rain forecast in the catchment area. The government ensures minimum water flows downstream into the sea and maximum water is used during the dam overflow period. This help in maximizing the annual allocation of a water share.
However, in the non-monsoon months, the measures for efficient use of the allocated water share typically includes:
Minimising the conventional and operational losses.
The National Green Tribunal(NGT) has formed a committee to investigate the alleged violation of norms in the construction of the Mekedatu project across the Cauvery river. The NGT has also directed the panel to submit a report on or before July 5.
About Mekedatu Project:
Mekedatu project is a balancing reservoir and drinking water project. It is to be built at the confluence of the Cauvery and Arkavathi rivers by the Karnataka Government.
Purpose: The project aims to solve the drinking water problems of the Bengaluru and Ramanagara district. It would also generate 400 MW of hydroelectric power.
Dispute: The Tamil Nadu Government has objected to the project saying Karnataka had not sought prior permission for the project.
Tamil Nadu has also filed a petition in the Supreme Court in 2018 seeking a stay on the project.
Objections by Tamil Nadu Government:
Firstly, the Mekedatu project would affect the flow of Cauvery water to Tamil Nadu.
Secondly, Karnataka has no right to construct any reservoir on an inter-state river without the consent of the lower riparian state i.e. Tamil Nadu in this case.
The project is also against the final order of the Cauvery Water Disputes Tribunal (CWDT). During that, the SC held that no state can claim exclusive ownership or assert rights to deprive other states of the waters of inter-state rivers.
Thirdly, The CWDT and the SC have found that the existing storage facilities available in the Cauvery basin were adequate for storing and distributing water. So, the Tamil Nadu Government is demanding outright rejection of the project.
Other concerns with the project:
Almost 63% of the forest area of the Cauvery Wildlife Sanctuary will be submerged in the project.
According to a study published in Nature Geoscience, Greenland’s glacial meltwaters have unusually high levels of mercury.
About the study:
Researchers from the Florida State University have analyzed the meltwater rivers. These rivers receive substantial amounts of water from the Greenland ice sheet.
The samples were filtered to remove any sediment and kept safe from contamination. Then the researchers analysed the mercury concentration in each one.
Key Findings of the study:
Firstly, researchers found high concentrations of mercury in the water bodies fed by the Greenland Ice Sheet.
Secondly, the mercury level was almost ten times the volume of mercury found in normal rivers.
Thirdly, the mercury level was also similar to that found in the polluted inland rivers of China.
How did mercury reach the water bodies of Greenland?
Mercury is a naturally occurring metal found in some rocks. As glaciers slowly flow downhill, the meltwater grinds up the underlying rocks. It results in mixing mercury into the meltwater.
Hence, the mercury did not end up in the meltwaters from industries or other anthropogenic activities, as is the case with most contaminants.
Significance of this study:
The findings will change the perception that glaciers have little or no influence on the Earth’s geochemical and biological processes.
Moreover, there is a concern that large volumes of mercury can reach the coastal food webs through bioaccumulation. It will impact the Arctic ecosystem.
Bioaccumulation: It refers to the process by which pollutants enter a food chain. Bioaccumulation occurs when an organism absorbs a toxic substance at a rate greater than that at which there is elimination of the substance.
Sypnosis: An International team conducted a study to understand the impact of Groundwater depletion on Cropping Intensity in India.
About the study:
The International team studied the impact of groundwater depletion on cropping intensity in India.
It analysed India’s three main irrigation types of winter cropped areas: dug wells, tube wells, canals. It also analyzed the groundwater data from the Central Ground Water Board.
Key Findings:
Impact on Cropping Intensity:
India is the world’s largest consumer of groundwater. India is also the second-largest producer of wheat in the world with over 30 million hectares in the country dedicated to producing this crop.
But with severe groundwater depletion, the cropping intensity or the amount of land planted in winter may decrease by up to 20% by 2025.
Most Impacted Region:
The study found that 13% of the villages in which farmers plant a winter crop are located in critically water-depleted regions.
These villages may lose 68% of their cropped area in the future if access to all groundwater irrigation is lost. The losses will largely occur in northwest and central India.
Alternative Sources of Irrigation:
The study analysed whether irrigation canals that divert surface water from lakes and rivers can make up for groundwater depletion.
It found that switching to irrigationcanal would favour farms close to canals, leading to unequal access.
Further, even if all regions that are currently using depleted groundwater for irrigation will switch to using canal irrigation, cropping intensity may decline by 7% nationally.
Hence, the study suggests the adoption of water-saving technologies. For instance, sprinkler, drip irrigation. Also, switching to less water-intensive crops may help use the limited groundwater resources more effectively.
Reasons for Groundwater Depletion in India:
The Green Revolution enabled the cropping of water-intensive crops like rice in water deficit regions such as Haryana and Punjab. It was ecologically less suitable for rice cultivation due to predominantly light soils.
This led to unsustainable groundwater use for irrigation and in turn groundwater scarcity.
Increased demand for water for domestic, industrial, and agricultural needs together with limited surface water led to the over-exploitation of groundwater resources.
Frequent pumping of water from the ground without waiting for its replenishment leads to quick depletion.
Subsidies on electricity and high Minimum Support Price(MSP) for water intensive crops.
Inadequate regulation of groundwater laws encourages the exhaustion of groundwater resources without any penalty.
Post harvest burning of crops, deforestation, unscientific methods of agriculture, chemical effluents from industries. It also led to pollution of groundwater making it unusable.
Way Forward:
There are enough groundwater resources with higher monsoon rainfall in eastern Indian states like Bihar.
But due to lack of enough irrigation infrastructure, farmers are not able to make use of natural resources there.
Hence, we need better policies in eastern India to expand irrigation and thus increase agriculture productivity. This will also release some pressure from northwestern Indian states.
UPSC IAS Prelims, Mains and Optional Papers mentions about many subjects. Geography is one of them. It is very important and conceptual subject. There are lots of facts as well. This subject we all have studied in our secondary schooling. So, more or less, we all are aware of this subject. Geography for UPSC consists of basic and advanced version of what we have studied earlier.
Geography is very interesting subject and it has overlapping topics for example, Economics (Human Geography), Environment and current events. So, it is important to read Geography for UPSC with right approach as it will be helpful for other subjects also. Every year UPSC ask around 10-12% questions from Geography in Prelims. We will see the trend analysis for Geography in UPSC Prelims exam:
Year
Total number of questions asked
2020
5
2019
7
2018
4
2017
7
2016
4
2015
11
In this article, we will discuss about how to read Geography for UPSC. First of all, we will see the overview of Geography syllabus for both UPSC Prelims and Mains:
Exam
Syllabus
UPSC Prelims- General Studies -Paper I
Indian and World Geography-Physical, Social, Economic Geography of India and the World.
UPSC Mains- General Studies- Paper I
Salient features of World’s Physical Geography.
Distribution of Key Natural Resources across the world (including South Asia and the Indian sub-continent); factors responsible for the location of primary, secondary, and tertiary sector industries in various parts of the world (including India).
Important Geophysical Phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc., geographical features and their location-changes in critical geographical features (including water-bodies and ice-caps) and in flora and fauna and the effects of such changes.
Study approach for Geography for UPSC:
Read the syllabus: The first and foremost thing before you start studying Geography for UPSC is to read the UPSC Syllabus for Geography multiple times so that you will get what exactly you have to study.
Start with NCERT textbooks: You must start with Class VI NCERT books for Geography. Preferably you can follow old NCERT textbooks. But if unable to get, can read new one as well. You must cover all NCERT books starting from Class VI to Class XII. Lists of some important NCERT books are:
Class XI: India: Physical Environment
Class XI: Fundamentals of Physical Geography
Class XII: Fundamentals of Human Geography
Basic books: After completing the NCERT books, you should read some basic books for Geography like Certificate Physical and Human Geography by GC Leong and Geography of India by Majid Husain. It will clear your concepts in detail. Referring a basic book is very important as questions are asked from these books (factual and conceptual).
Refer Previous Years’ Question Papers: At this stage, you must UPSC Prelims and Mains Past Years’ Question Paper. This will give idea about what kinds of questions are asked in Prelims and Mains. It will also help to identify the important topics from the exam perspective and help you to revise the topic again and again.
Solve mock tests: You need to solve mock tests as many as possible. It will help you to identify your strengths and weaknesses regarding topics. Based on these, you can assess your performance and will focus more on your weak areas and topics.
Current affairs magazine: You should refer one current affair monthly magazine. This will help you to link and update your preparation with day-to-day events. For example, reasons for early arrival of monsoon, cyclone in particular state or country etc.
Newspaper reading: You must read one newspaper on a daily basis. Sometimes, articles of newspaper explain some topics which are linked to both static and dynamic portion of Geography for UPSC. For example, El Nino and La Nina.
Map reading and practice: Reading Geography for UPSC is incomplete without Map. Almost everything is Geography is related to Map, whether it is soils, mining, mineral, ocean, rivers everything. Map makes it easy to understand and related everything with location. With the help of Map, we make a 3D picture in our mind, which helps us to easily represent anything (mainly resources, rivers, places) with exact location. For that you need to practice map. Based on current events, you can identify areas which are in news and you can locate that on your map. From the perspective of UPSC Prelims, it is very important as UPSC asks at least 1-2 questions in Geography map based.
Miscellaneous sources: You should refer some monthly magazines like Yojana and Kurukshetra. It will help in current affairs and will increase the quality of your answer.
Revise: You should keep revising the subject as many topics are factual and concepts based. Revision will help you to grasp the things easily and will save your time while solving MCQs and writing answers.
Geography is very interesting subject. With correct strategy and study plan, one can score well in the exam.
