Geography: March 2023 UPSC Current Affairs | Current Affairs & Hindu Analysis: Daily, Weekly & Monthly PDF Download

Demand for Lightning to be Declared a Natural Disaster

In News

• Some Indian States have recently demanded lightning to be considered a natural disaster.

About

• At present, Cyclone, drought, earthquake, fire, flood, tsunami, hailstorm, landslide, avalanche, cloudburst, pest attack, frost, and cold waves are considered disasters.
• These disasters are covered under the State Disaster Response Fund (SDRF) which is 75% funded by the Centre.
• Lightning prevalence is more at night and early hours in hilly states and more during the day in the plains.
• Strikes can cause cardiac arrest and severe burns, but 9 of every 10 people survive.
• Hundreds more survive strikes but suffer from a variety of lasting symptoms, including memory loss, dizziness, weakness, numbness, and other life-altering ailments.
• Lightning is dangerous, and about 2,000 people are killed worldwide by lightning each year with farmers being the most affected and deaths are more during the rainy season.
• India is among only five countries in the world that has an early warning system for lightning in which the forecast is available from five days to up to three hours in advance of the predicted event.

What is lightning?

• Lightning is an electrical discharge caused by imbalances between storm clouds and the ground, or within the clouds themselves where most of the lightning occurs.
• During a storm, colliding particles of rain, ice, or snow inside storm clouds increase the imbalance between storm clouds and the ground, and often negatively charge the lower reaches of storm clouds.
• Objects on the ground, like steeples, trees, and the Earth itself, become positively charged—creating an imbalance that nature seeks to remedy by passing current between the two charges.
• Cloud-to-ground lightning bolts are a common phenomenon with about 100 striking Earth's surface every second.
• A typical cloud-to-ground lightning bolt begins when a step-like series of negative charges, called a stepped leader, races downward from the bottom of a storm cloud toward the Earth along a channel at about 200,000 mph (300,000 kph).

Impact of Lightning

• Madhya Pradesh had the highest number of lightning-related deaths (162), followed by Maharashtra (121), Gujarat (72), Bihar (70), Rajasthan (49), and Chhattisgarh (40).
• India has experienced 90,632 deaths due to lightning strikes between 1972 and 2019.
• The Accidental Deaths & Suicides in India 2021 report confirms that 40.4% of deaths due to natural disasters took place due to lightning.
• Lightning adversely impacts the agriculture, aviation, power, and communication sectors.
• Rural and forest areas are the most vulnerable due to the presence of water bodies and tall trees.
• 96% of lightning deaths occurred in rural areas.
• 77% of farmers are killed due to lightning as they work in agricultural fields during the Kharif cropping season in the monsoon period.

Challenges of Lightning in India

• High mortality rate: Lightning strikes kill more than 2,000 people in India every year, making it one of the deadliest weather-related hazards in the country.
• Lack of awareness: There is a lack of awareness among the general public about the dangers of lightning, which often leads to fatalities and injuries.
• Poor lightning protection infrastructure: Most buildings and structures in India are not equipped with lightning protection systems, making them vulnerable to lightning strikes.
• Limited lightning data: There is limited data on lightning strikes in India, which makes it difficult to develop effective lightning protection policies and strategies.
• Climate change: Climate change is expected to increase the frequency and intensity of thunderstorms, which could lead to more lightning strikes in the future.
• Limited resources: India has limited resources to invest in lightning protection infrastructure and research, which makes it challenging to mitigate the risks associated with lightning.

Government steps for disaster management

• Disaster Management Act, 2005: The act provides a legal framework for the management of disasters in the country and lays down the responsibilities of various agencies and authorities and outlines the procedures for disaster management.
• National Disaster Management Authority (NDMA): It was established in 2005 to provide a comprehensive and integrated approach to disaster management in the country. 
• State Disaster Management Authorities (SDMAs): Each state has a separate SDMA which works in coordination with the NDMA and other agencies to mitigate the impact of disasters.
• National Disaster Response Force (NDRF): The NDRF is a specialized force created to respond to disasters and provide relief & rescue operations and comprises battalions stationed across the country.
• Early Warning Systems: The government has set up early warning systems for various disasters, such as cyclones, earthquakes, floods, and landslides. These systems use technology to provide timely warnings to people in the affected areas.
• Capacity building: The government has initiated various capacity-building programs to improve the skills and knowledge of the stakeholders involved in disaster management. 
• National Disaster Management Plan (NDMP): It is a comprehensive plan developed by the government to address all aspects of disaster management, including prevention, mitigation, and response. 
• International cooperation: The government has signed various agreements with other countries and international organizations to share knowledge, resources, and best practices in disaster management.

What more can be done?

• The government should include lightning as a “natural disaster” to minimise lightning-related deaths.
• Mapping vulnerable populations with potential lightning hotspots, improving early warning systems, and installing lightning detection systems are critical measures.
• The government should prepare a database related to lightning strikes, gender-wise lightning deaths, and occupation-wise fatalities at the district, state, and central levels for devising an action plan against lightning strikes.
• Training and community awareness programs are essential measures to minimise deaths due to lightning.

Way ahead

• Although the government has taken several steps to improve disaster management in India, there is a need to bring lightning under its ambit.
• While there are still challenges to be addressed, targeted steps can help in building a robust disaster management system in the country.

Landslide Atlas of India

In News

• ISRO recently released the Landslide Atlas of India identifying landslide hotspots in the country.

About 

• ISRO’s National Remote Sensing Centre created a database of landslide-prone regions of India based on events during 1998 – 2022.
• In addition to aerial images, high-resolution satellite images captured using ResourceSat-1 and 2, etc., were used to study the landslides.
• The pan-India database classifies landslides into – seasonal (2014, and 2017 monsoon seasons), event-based and route-based (2000 – 2017).

What are Landslides?

• A landslide is defined as the movement of a mass of rock, debris, or earth down a slope.
• They are a type of mass wasting, which denotes any downward movement of soil and rock under the direct influence of gravity. They generally occur in clay-rich soil.
• In India the entire Himalayan tract, hills/mountains in sub-Himalayan terrains of North-east India, Western Ghats, the Nilgiris in Tamil Nadu and Konkan areas are landslide-prone.

India’s Vulnerability

• India is among the top five landslide-prone countries globally, where at least one death per 100 sq km is reported in a year due to a landslide event.
• Excluding snow-covered areas, the Atlas states that 
  • approximately 12.6 per cent of the country’s geographical land area (0.42 million sq km) is prone to landslides. 
  • As many as 66.5 percent of the landslides are reported from the North-western Himalayas, about 18.8 per cent from the North-eastern Himalayas, and about 14.7 per cent from the Western Ghats.
  • Rainfall variability pattern is the single biggest cause of landslides in the country, with the Himalayas and the Western Ghats remaining highly vulnerable.

Region-wise Distribution

• Nearly half of the country’s landslide-prone area (0.18 sq km) is located in the states of Assam, Arunachal Pradesh, Sikkim, Meghalaya, Mizoram, Manipur, Tripura and Nagaland.
• Uttarakhand, Himachal Pradesh, Jammu and Kashmir cover 0.14 million sq km of the total landslide-prone areas.
• Maharashtra, Goa, Karnataka, Kerala, and Tamil Nadu account for 0.09 million sq km.
• The Araku region in Andhra Pradesh along the Eastern Ghats too has reported landslide events.

State-wise Distribution

• Uttarakhand, Kerala, Jammu and Kashmir, Mizoram, Tripura, Nagaland and Arunachal Pradesh reported the highest number of landslides during 1998 – 2022.
• Mizoram topped the list, recording 12,385 landslide events in the past 25 years, of which 8,926 were recorded in 2017 alone. 
• 2,071 events of the total 2,132 landslides reported in Nagaland during this period occurred during the 2017 monsoon season. 
• Manipur, too, showed a similar trend, wherein 4,559 out of 5,494 landslide events were experienced during the rainy season of 2017.

• Of the total 690, Tamil Nadu suffered 603 landslide events in 2018 alone.
• The Himalayan state of Uttarakhand has experienced the second-highest number (11,219) of landslides since 1998, all events occurring post-2000.
• Despite fewer events in the Western Ghats, landslides were found to be making inhabitants significantly vulnerable to fatalities, especially in Kerala.

Government Initiatives to deal with landslides

• National Landslide Risk Management Strategy (2019): 
  • It covers all aspects of landslide disaster risk reduction and management, such as hazard mapping, monitoring, and early warning systems.
  • It includes awareness campaigns, capacity building, training, regulations, and policies, as well as landslide stabilisation and mitigation.
• National Disaster Management Authority (NDMA) Guidelines on Landslide Hazard Management (2009):
  • It outlines the steps that should be taken to reduce the risk of landslides.
  • It also identifies regions that are prone to landslides
  • Encourages the use of effective landslide rehabilitation and mitigation techniques.
• National Institute of Disaster Management (NIDM):
  • It was set up to provide capacity building and support to various national and state-level authorities in the area of disaster management and disaster risk reduction.

Glacial Retreat

Why in News?

Recent studies on Himalayan glaciers show that the variability in retreat rate and mass balance in different sectors of the mountain range is primarily linked to topography and climate.

• However, variable retreat rates of glaciers and inadequate supporting field data make it challenging to develop a coherent picture of climate change impact.

What are the Factors Influence Glacial Dynamics?

• A team from Wadia Institute of Himalayan Geology (Uttarakhand) studied two glaciers with different characteristics, the Pensilungpa Glacier (Ladakh) and the Durung-Drung Glacier, (Ladakh) for a comparative study of glacier fluctuations between 1971 and 2019.
• They quantitatively evaluated the influence of the debris cover on the loss of ice mass in summer and on the terminal recession of glaciers.
• Their study confirms that the glacier retreat rate is controlled by climate change and the topographic setting and morphology of the glacier.
• They also found that the thickness of the debris cover significantly alters the glacier response to climate forcing.
• Other factors such as snout geometry, glacier size, elevation range, slope, aspect, debris cover, as well as the presence of supra and proglacial lakes also influence the heterogeneous glacial dynamics.

What is Glacial Retreat?

• About:
  • Glacial retreat refers to the process of a glacier shrinking or receding in size over time due to a decrease in ice accumulation or an increase in ice melt.
• Causes:
  • This can be caused by a number of factors, including rising global temperatures, changes in precipitation patterns, or changes in the geography of the surrounding landscape.
• Impacts:
  • As a glacier retreats, it can lead to a number of significant environmental impacts, including changes in water availability, alterations to local ecosystems, and increased risk of natural disasters such as floods and landslides.
  • In addition, the loss of glacial ice can contribute to rising sea levels, which can have significant impacts on coastal communities and ecosystems around the world.

Tapping into Helium Reserves

Why in News?

Researchers propose a new model to tap into helium reserves to address shortage issues and a recent new study suggests that reservoirs of this gas, with no carbon footprint, likely exist in geological formations beneath the Earth.

• The helium production process comes with a high carbon footprint as its production is related to drilled natural gas or oil.

What is the Proposed Model to Tap Helium Reserve?

• The gas can be produced and stored in crystalline basement rocks, dense rocks that extend from the mantle to the near-surface or surface.
• These rocks naturally contain uranium and thorium, both of which decay to form helium naturally.
• These rocks are 30-40 kilometre thick. They have also existed for millions or billions of years, allowing large amounts of helium to be produced and stored.
• Also, these rocks could also be a source of hydrogen. The model showed that energy generated from the radioactive decay of uranium and thorium could split water to form hydrogen.

What is the Significance of Helium Gas?

• About:
  • Helium is a noble gas and has a closed-shell electronic configuration, making it stable and unreactive.
  • It has the lowest boiling and melting points of any element and exists only as a gas, except under extreme conditions.
• Discovery of Helium:
  • Helium was first discovered in 1868 by French astronomer Jules Janssen and English astronomer Joseph Norman Lockyer, who observed a yellow spectral line in the light emitted by the sun during a solar eclipse.
  • Helium gets its name from the Greek word "helios," which means sun.
• Sources and Extraction of Helium:
  • Helium is the second most abundant element in the universe, after hydrogen. However, it is relatively rare on Earth, with most of it being produced by the decay of radioactive elements in the Earth's crust.
  • Natural gas is the primary source of helium on Earth.
  • Helium is extracted from natural gas using a process called cryogenic distillation.
• Reserves and Production:
  • As of 2022, the reserves of helium in the United States has the largest reserves of helium globally followed by Algeria and Russia.
  • India’s Rajmahal volcanic basin in Jharkhand is the storehouse of helium trapped for billions of years.
• Uses of Helium:
  • Balloons and airships (because it is lighter than air and does not react chemically with other elements).
  • Industrial applications, including welding, cooling, and as a protective gas in the production of semiconductors and fiber optic cables.
  • In medical applications, such as magnetic resonance imaging (MRI), as a cooling agent for superconducting magnets.
  • It is also used in nuclear magnetic resonance (NMR) spectroscopy and as a carrier gas in gas chromatography.
• Shortage of Helium:
  • There is currently a shortage of helium in the world, with demand outstripping supply.
  • The shortage is due to a variety of factors, including the shutdown of some helium plants, the increasing demand for helium in emerging economies, and the lack of new helium sources.
  • The shortage of helium has led to concerns about its use in balloons and airships, as well as its use in medical and industrial applications.

Conclusion

The proposed model for tapping into carbon-free helium reserves could provide a sustainable and cost-effective solution to the current helium shortage, with the added benefit of hydrogen production.

Daylight Saving Time

Why in News?

Recently, the Lebanon Government has delayed the start of Daylight-Saving Time (DST) by a month. Meanwhile, Greenland has chosen to stay with DST forever.

• Lebanon usually sets its clocks forward an hour on the last Sunday in March. However, its Prime Minister said this year, the clocks would be reset on 21 April, without citing any reason.

What is Daylight Saving Time?

• According to Norway-based Time and Date, DST is the practice of setting the clocks forward one hour from the standard time during the summer and back again in the autumn.
• This is done to make better use of natural daylight. India does not follow daylight saving time as countries near the Equator do not experience high variations in daytime hours between seasons.

What is the Significance of DST?

• Those in favour of DST argue that it means a longer evening daytime. Individuals will complete their daily work routines an hour earlier, and that extra hour of daylight means a lower consumption of energy.
• In April 1916, during World War I, Germany and Austria introduced DST to minimise the use of artificial lighting. It gradually caught on in many countries.
• In the EU, clocks in the 28 member states move forward on the last Sunday in March and fall back on the last Sunday in October.

What are the Disadvantages of DST?

• According to a study in Popular Science magazine in the US, one hour of lost sleep in the US increases the fatal crash rate by 5.4% to 7.6% for six days following the transition.
• Other studies found a higher rate of workplace injuries after the switch, leading to lost days of work; a slight drop in stock market performance; health problems as a result of disruption of the Circadian Rhythm.

Atmospheric Rivers

Why in News?

California has experienced an exceptionally wet winter with 11 atmospheric rivers battering the state since late December 2022.

What are Atmospheric Rivers?

• About:
  • Atmospheric rivers are relatively long, narrow regions in the atmosphere – like rivers in the sky – that transport most of the water vapor outside of the tropics.
  • One well-known atmospheric river called the “Pineapple Express” picks up warm, moist air near Hawaii.
  • When the Pineapple Express hits land in the Western United States and Canada, it can cause heavy rain and snow. In California, it can cause up to 5 inches of rain in a day.
  • Atmospheric rivers typically occur in the extratropical North Pacific/Atlantic, southeastern Pacific, and South Atlantic oceans often making landfall on the west coasts of North and South America. Other regions that experience atmospheric river landfalls include Greenland, Antarctica, and the south-central United States.
• Formation:
  • Atmospheric rivers usually begin over tropical regions. Warm temperatures cause ocean water to evaporate and rise into the atmosphere. Strong winds help to carry the water vapor through the atmosphere.
  • As atmospheric rivers move over land, the water vapor rises up farther into the atmosphere. It then cools into water droplets, which fall as precipitation.
• Impacts:
  • Heavy rainfall associated with ARs can cause flooding, landslides, and mudslides.
  • They can also lead to water supply disruption, and develop drought-like conditions.
• Significance:
  • Not all atmospheric rivers cause damage; most are weak systems that often provide beneficial rain or snow that is crucial to the water supply.
• Climate Change:
  • Climate change is expected to increase the frequency and intensity of ARs in some regions of the world, particularly in the mid-latitudes.
  • This could have significant implications for water resources management, flood control, and other areas of public policy.

Changing Western Disturbances

Why in News?

According to recent studies, the changing character of Western Disturbances might be the primary cause of the abnormal winter seasons in India.

• India has not experienced a normal winter season in the past three years. The second wettest season in the country after the monsoons has remained unusually dry and hot.

How Western Disturbances Affected Winters in India Recently?

• The northwest region of India, which receives almost 30% of its annual rainfall during the winter season, saw an 83% and 76% rainfall deficit in December 2022 and February 2023 respectively.
• The absence of Western Disturbances caused the north Indian plains to experience severe cold waves and cold days in December 2022 and most of January 2023 due to the cold northern winds flowing down from the Himalayas.
• Western Disturbances are also responsible for hailstorms that damage standing crops, fog events that interrupt air, rail and road services and cloud bursts that result in flash floods.

How Western Disturbances are Affected by Other Climatic Phenomena?

• La Nina Event:
  • For the past three years, the world has been in a La Niña phase, which refers to the cooling of ocean surface temperature in the Pacific Ocean.
  • It weakens the temperature gradient for the formation of Western Disturbances as it reduces the temperature of the hot tropical air.
• North Atlantic Oscillation:
  • Western Disturbances are also influenced by the North Atlantic Oscillation, a random fluctuation of air pressure over the North Atlantic Ocean due to a high-pressure region above the Azores Islands in the central North Atlantic and a low-pressure region over Iceland.
  • Due to this, the weather system is currently in a negative phase, as both low- and high-pressure systems are weak, and it makes Western Disturbances 20% less frequent and 7% less intense than a positive phase.
• Subtropical Jet Stream:
  • The northward shift of the subtropical westerly jet stream not only reduces the chance of Western Disturbances striking India but also increases the chance of them affecting higher latitudes such as the Tibetan Plateau or even as far up as China and Russia.
  • This could indirectly affect the southwest monsoon, which accounts for 80% of India’s annual rainfall.
• Interaction with Southwest Monsoon:
  • The warming of the Arctic region makes the polar front jet wavier, causing Western Disturbances to visit India more frequently during summers.
  • Western Disturbances during summer, monsoon, and post-monsoon periods increase the chances of them interacting with the southwest monsoon and other associated local convection systems such as tropical depressions that travel northward from either the Bay of Bengal or the Arabian Sea.
  • Such interactions can cause catastrophic weather disasters.
  • For instance, In May 2021, a remnant of the extremely severe cyclone Tauktae, which made landfall along the Gujarat coast, travelled all the way to Delhi and interacted with a Western Disturbance to cause heavy rainfall in Delhi and its vicinity.

Vernal Equinox

Why in News?

The vernal equinox is observed on March 21st 2023.

What is Equinox?

• About:
  • Equinox happens twice a year when the sun is directly above the equator, and it occurs on approximately 21^st March and 23^rd September.
  • During an equinox, both the Northern and Southern Hemispheres have equal day and night time. The vernal equinox (spring equinox) takes place in the Northern Hemisphere around 20^th or 21^st March, while in the Southern Hemisphere, it happens on 22^nd or 23^rd September.
  • Conversely, during the autumn season in the Northern Hemisphere on 23rd September (autumn equinox), it is springtime in the Southern Hemisphere, and on 21^st March, it is the opposite.
• Significance:
  • As a result, the Sun is located directly above the equator, and both hemispheres receive an almost equal amount of sunlight.
  • After the spring equinox, the northern hemisphere tilts closer to the sun in March, resulting in more hours of daylight, with earlier sunrises and later sunsets.
  • According to Hindu astrology, Vernal Equinox is known as Vasant Vishuva or Vasant Sampat.
  • The Spring equinox brings earlier sunrises, later sunsets, and sprouting plants in the northern hemisphere.
  • Later sunrises, earlier sunsets, chillier winds, and dry and falling leaves are observed in the south of the equator (southern hemisphere).