Daily Prelims Notes 2 June 2024
- June 2, 2024
- Posted by: OptimizeIAS Team
- Category: DPN
Daily Prelims Notes
2 June 2024
1. What grade of coal does India produce?
Sub: Geography
Sec: Eco geo
Context:
- A recent report by the Organized Crime and Corruption Reporting Project alleged that in 2014, the Adani Group claimed ‘low grade’ coal, imported from Indonesia, to be ‘high-quality’ coal’ inflated its value and sold it to Tamil Nadu’s power generation company.
More on news:
- There are 17 grades of coal by this metric from grade 1, or top quality coal, with a kilo of it yielding higher than 7,000 kcal, and the lowest producing anywhere between 2,200-2,500 kcal, as per a classification by the Coal Ministry.
- The Central Electricity Authority (CEA) in 2012 recommended that about 10-15% blending of imported coal can be safely used in Indian power boilers, which are designed for low quality Indian coal.
What are high grade’ and ‘low grade’ coal?
- Higher quality coal produces less smoke, burns longer, and provides more energy than lower quality coal.
- Low-rank coals are those that have undergone minimal metamorphic variation in the process of coal formation.
- Compared with the high-rank coals—bituminous and anthracite, they retain more moisture and volatile and contain less fixed carbon.
Parameters to determine the quality of Coal:
- High and low quality are relative terms and only meaningful in the context of where the coal is used and how they are processed.
- The Gross Calorific Value (GCV), or the amount of heat or energy that can be generated from burning the coal, determines the gradation of coal.
- Coal being a fossil fuel is a mixture of carbon, ash, moisture and a host of other impurities.
- The higher the available carbon in a unit of coal, the greater is its quality or ‘grade.’
- The calorific value is not a useful metric on its own.
- The most important uses of coal are in running thermal power plants or powering a blast furnace to produce steel and both require different kinds of coal.
- ‘Coking’ coal is the kind needed to produce coke — an essential component of steel making — and thus requires minimal ash content.
- Non-coking coal, despite its ash content, can be used to generate enough useful heat to run a boiler and turbine.
What are the characteristics of Indian coal?
- Indian coal has historically been evaluated as being high in ash content and low in calorific value compared to imported coal.
- The average GCV of domestic thermal coal ranges from 3,500-4,000 kcal/kg compared to imported thermal coals of +6,000 kcal/kg of GCV.
- The average ash content of Indian coals is more than 40% compared to imported coal which has less than 10% ash content.
- The consequence of this is that high-ash coal when burnt results in higher particulate matter, nitrogen and sulfur dioxide.
- The government, since 1954, has controlled the price of coal in a way that power companies were disincentivised to use high-grade coking coal for power generation.
What is clean coal?
- Clean coal technologies are several generations of technological advances that have led to more efficient combustion of coal with reduced emissions of sulfur dioxide and nitrogen oxide.
- “Clean coal” usually means capturing carbon emissions from burning coal and storing them in underground pockets of porous rock
- We get clean coal when the carbon content has been increased by reducing its ash content.
- Coal plants have ‘washing plants’ on site which can process the coal in ways that reduce ash and moisture content.
- They employ huge blowers or a ‘bath’ to remove fine, coarse ash.
- The other method to clean coal is coal gasification.
- The need to directly burn coal is bypassed by converting it into gas.
- By relying on an integrated gasification combined cycle (IGCC) system, steam and hot pressurized air or oxygen combine with coal in a reaction that forces carbon molecules apart.
- The resulting syngas, a mixture of carbon monoxide, hydrogen, CO2 and water vapor, is then cleaned and burned in a gas turbine to make electricity.
- Since IGCC power plants create two forms of energy (steam from the gasification process apart from syngas as fuel), they increase efficiency of the coal used.
What is the future of coal in India?
- India is the second-largest coal producer in the world, after China.
- India, the world’s second largest coal consumer of coal.
- Official data says that India in 2023-24 produced 997 million tonnes of coal, an 11% growth over the previous year.
- Most of this was produced by the state-owned Coal India Ltd and its subsidiaries.
- As of March 2024, India produced 261 tonnes of coal, of which 58 million tonnes was coking coal. Renewable energy accounted for 71.5% of the record 13.6 GW power generation capacity added by India in the first quarter of this year, while coal’s share (including lignite) of total power capacity dropped below 50% for the first time since the 1960s.
2. Archaeologists, Sanskrit scholars tie up to decipher Rigveda text
Sub: History
Sec: Ancient India
Context:
- In order to establish a relationship between the Harappan civilisation and the people of the Vedic age, a group of archeologists are now collaborating with Sanskrit scholars to decipher the text of the Rigveda.
More on news:
- According to scholars, a clear understanding of what is mentioned in the Rigveda text is important in order to co-relate archaeological evidence unearthed by his team in excavations of Harappan settlements at Haryana’s Rakhigarhi and Banawali, at Kalibanga on the Haryana-Rajasthan border, and at Dholavira in Gujarat.
Key highlights:
NCERT new additions:
- The Harappan Civilisation’, based on DNA evidence from the 4,600-year old remains of a woman, indicating that the Harappans were an indigenous people.
Evidence from Rakhigarhi:
- While excavating the site of Rakhigarhi,evidence of ritual platforms and fire altars are found.
- Parallely, fire worship is mentioned in Rig Vedic texts.
Saraswati: a common thread:
- The mention of the river is recorded at least 71 times in the Rigvedic text.
- During archaeological excavations, scholars discovered a majority of Harappan settlements along the banks of river Saraswati.
- Of the nearly 2,000 known Harappan settlements spread over the Indus basin, Saraswati, and in Gujarat, of which almost two-thirds, at least 1,200 are located along the basin of the river Saraswati.
Cities and Towns life:
- DNA evidence now suggests that cities and towns first came into existence during the Harappan times, dating 4,500 to 4,600 years ago.
- They again later came into existence 2,400 years ago, by which time proofs of use of iron also emerged.
- In the middle, there seems to be a decline, where humankind reverted back to rural life.
- The later settlements were not along the banks of river Saraswati.
- The Rigveda talks about river Saraswati, and we only have proof of dense Harappan settlements there, dating back to 4,600 years ago.
- Rigvedic texts do not mention the use of iron, so co-relation with early historic settlements which came much later and are 2,400 year old ones (near the Ganga Basin and the Deccan region) is not possible.
A debate on animal bones:
- Another point of reference which may link the Harappans with Vedic times is a set of animal bones found and studied by two archaeo-zoologists in the Surkotada region of Kutch, Gujarat.
- Some terracotta figurines of horse-like animals have been excavated from the Harappan sites of Lothal and Mohenjo Daro.
Linkage with Modern Humans:
- Studies wrt to DNA analysis from the blood samples of 3,000 modern south Asians from different linguistic and religious groups were carried out.
- It was found that most of them were from the Andaman and Nicobar islands to Ladakh and Kashmir, and from Afghanistan to Bengal and carried genetic similarities to the Harappan woman’s skeleton.
About Harappan Civilisation:
- Indus Valley Civilization was the first major civilization in South Asia, which spread across a vast area of land in present-day India and Pakistan (around 12 lakh sq.km).
- The time period of mature Indus Valley Civilization is estimated between BC. 2700- BC.1900 ie. for 800 years.
Indus Valley Sites and Specialties:
Harappa
- Seals out of stones
- Citadel outside on banks of river Ravi
Mohenjodaro
- Great Bath, Great Granary, Dancing Girl, Man with Beard, Cotton, Assembly hall
- The term means ” Mount of the dead”
- On the bank of river Indus
- Believed to have been destroyed by flood or invasion(Destruction was not gradual).
Chanhudaro
- Bank of Indus river. – discovered by Gopal Majumdar and Mackey (1931)
- Pre-Harappan culture – Jhangar Culture and Jhukar Culture.
Kalibangan
- At Rajasthan on the banks of river Ghaggar, discovered by A.Ghosh (1953)
- Fire Altars
- Bones of camel
- Evidence of furrows
- Horse remains ( even though Indus valley people didn’t use horses).
- Known as the third capital of the Indus Empire.
About Rig Vedic Age or Early Vedic Period (1500–1000 BCE):
- In the Rig Vedic period, the Aryans were mostly confined to the Indus region.
- It refers to Sapta Sindhu or the land of seven rivers.
- This includes the five rivers of Punjab, namely Jhelum, Chenab, Ravi, Beas and Sutlej along with the Indus and Saraswati.
- The Rigveda Samhita contains about 10552 Mantras, classified into ten books called Mandalas.
- Each Mandala is divided into several sections called Anuvakas.
- Each Anuvaka consists of a number of hymns called Suktas and each Sukta is made up of a number of verses called riks
About Saraswati River:
- The Saraswati is called the Ghaggar-Hakra river and flows only during the monsoon season.
- It originates from the Shivaliks, the foothills of the Himalayas, then flows through Punjab, Haryana, and a part of Rajasthan before entering what is now Pakistan.
- The Indian part of the river is named the Ghaggar, while the one in Pakistan is the Hakra
3. Tamil Nadu forms 20 village committees to strengthen the protection of the mangrove ecosystem
Sub: Environment
Sec: Ecosystem
Context:
- The IUCN has designated mangroves in Tamil Nadu, Sri Lanka, and Maldives as ‘critically endangered’ in its first global assessment of mangrove ecosystems.
Village mangrove committee of Tamil Nadu:
- To protect mangrove cover, the Tamil Nadu Forest Department has formed 20 village mangrove committees.
- Of the 36 geographical areas assessed globally, only South India, Sri Lanka, Maldives, and the warm temperate northwestern Atlantic region have critically endangered mangroves.
- The assessment in South India considered mangroves in Muthupet, Ramanathapuram, and a small part of southern Kerala.
About IUCN Assessment of mangroves forest:
- First-ever global assessment.
- Published: Red List of Mangrove Ecosystems
- Major findings: More than half of the world’s mangroves are at risk of collapse by 2050.
- In the absence of additional conservation efforts, by 2050, about 7,065 km2(- 5%) more mangroves will be lost and 23,672 km2 (-16%) will be submerged due to sea level rise.
Mangroves:
- Mangroves are a group of trees and shrubs that live in the coastal intertidal zone.
- There are about 80 different species of mangrove trees. All of these trees grow in areas with low-oxygen soil, where slow-moving waters allow fine sediments to accumulate.
- Mangrove forests only grow at tropical and subtropical latitudes near the equator because they cannot withstand freezing temperatures.
- Many mangrove forests can be recognized by their dense tangle of prop roots that make the trees appear to be standing on stilts above the water. This tangle of roots allows the trees to handle the daily rise and fall of tides, which means that most mangroves get flooded at least twice per day.
- Mangrove forests stabilize the coastline, reducing erosion from storm surges, currents, waves, and tides.
- The threats to mangroves have evolved, with past issues including wood exploitation and agriculture, now compounded by climate change, sea-level rise, and severe cyclonic storms.
Pneumatophores (or Aerial roots):
- Aerial roots are roots growing above the ground.
- They are often adventitious, i.e. formed from non-root tissue.
- They are found in diverse plant species, including epiphytes such as orchids (Orchidaceae), tropical coastal swamp trees such as mangroves, banyan figs (Ficus subg. Urostigma), the warm-temperate rainforest rata (Metrosideros robusta), and pohutukawa trees of New Zealand (Metrosideros excelsa).
- Vines such as common ivy (Hedera helix) and poison ivy (Toxicodendron radicans) also have aerial roots.
Mangroves in Tamilnadu:
- In Tamil Nadu, the mangrove area has doubled from 23 sq.km in 2001 to 45 sq.km in 2021, according to the Indian State of Forest Report.
- Tamil Nadu’s mangrove degradation is less severe than in neighbouring islands, though Muthupet was heavily damaged by the Gaja Cyclone.
- Mangrove restoration has been completed in about 25 sq. km across several districts in Tamil Nadu, with another 15 sq. km proposed under the World Bank-funded Tamil Nadu Coastal Restoration Mission.
- The State government is emphasizing the scientific management of mangroves and involving local communities in their protection, providing them with benefits like fisheries, non-wood products, and livelihood protection against storm surges.
Mangrove forests in India:
Source: TH
4. Cities warming due to the combined effect of urbanisation, climate change
Sub: Geography
Sec: Climatology
Context:
- Recently, Delhi experienced daytime temperatures above 50°C for two consecutive days, the highest ever recorded in the city.
- Cities are experiencing higher temperatures due to ongoing climate change and rapid urbanization, which are defining the Anthropocene.
Details:
- India’s urban population is projected to double by 2050, adding more than 450 million residents, surpassing the current total population of the United States and the European Union.
- The urban heat island (UHI) effect makes cities warmer than rural areas by trapping more heat due to altered thermodynamic and aerodynamic properties.
- Climate change is causing significant increases in record-breaking temperatures and prolonged heat waves, contributing to complex warming in cities.
- This altered micro-climate affects heat, rainfall distribution, air pollution dispersion, and public health, necessitating scientifically informed urban planning.
Urban Heat Island:
- Urban heat island may be defined as the local and temporary phenomenon in which certain pockets within a city are experiencing higher heat load than its surrounding area.
- This rise of heat basically happens due to buildings and houses of cities made up of concrete where the heat is trapped and not able to dissipate easily.
- Urban heat island is basically induced due to trapped heat between establishments made up of concrete.
- The temperature variation can range between 3 to 5 degrees Celsius.
Study on warming effects:
- A recent study sought to separate the warming effects of local urbanization and regional climate change in 141 major Indian cities.
- The study used high-resolution night-time land surface temperature data from NASA’s MODIS sensor, comparing urban and rural temperatures from 2003 to 2020.
- Results showed that the rate of warming in cities is nearly twice that of the rest of the country, with urbanization alone causing additional warming of about 60%.
- An average increase of 0.53°C per decade in night-time land surface temperature was observed, with tier-II cities in eastern India experiencing stronger urbanization-driven warming than larger metros.
India’s efforts to reduce warming effects:
- India is actively reducing emissions and shifting to non-fossil fuel energy sources, as outlined in its updated nationally determined contribution (NDC) for climate justice.
- State-level heat action plans and early warning systems for heatwaves show India’s commitment to reducing heat-related mortality.
Recommendations:
- Tailored city-specific action plans are needed for sustainable urban growth, considering the predominant contributors to warming.
- Urban heat management should follow a differential approach: local-scale interventions (cool roofs, green infrastructure, urban forests) for cities with high urbanization contributions, and regional-scale efforts (large-scale afforestation, rejuvenation of water bodies) for cities with higher climate change impacts.
Source: TH