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Subject: Environment

  • [pib] River erosion in Ladakh Himalayas

    Indian researchers have studied rivers in Ladakh Himalaya, bringing out 35 thousand-year histories of river erosion and identified hotspots of erosion and wide valleys that act buffer zones.

    Click here to read more about the Himalayan river systems and its orogeny

    Erosion hotspot: Ladakh region

    • The Ladakh Himalaya forms a high altitude desert between Greater Himalayan ranges and Karakoram Ranges.
    • The Indus and its tributaries are major rivers flowing through the terrain.
    • The Zanskar River is one of the largest tributaries of the upper Indus catchment, draining orthogonally through highly deformed Zanskar ranges.

    Zanskar: A major river in Ladakh

    • Two prominent tributaries of Zanskar River are the Doda and Tsrap Lingti Chu, which confluence at Padam village in the upper valley to form the Zanskar River.
    • Zanskar catchment was explored to understand the landform evolution in the transitional climatic zone, using morpho-stratigraphy and study of landforms like valley fill terraces, alluvial fans (triangle-shaped deposit of gravel, sand, and even smaller pieces of sediment, such as silt).

    Zanskar Padam

    • Zanskar river makes a deep gorge in its lower reaches with the headwaters in upper Zanskar makes wide basin called as Padam.
    • The basin stores large amount of sediments in form of fans and river terrace deposits
    • The research suggested that the wide valley of Padam, with an area of 48 square km, in the upper Zanskar, has stored a vast amount of sediments in these landforms.
    • Thus Padam valley is a hotspot of sediment buffering in the Zanskar.

    Sediment study reveals the erosion

    • The study suggested that most sediments were derived from Higher Himalayan crystalline that lies in the headwater region of Zanskar.
    • It was found out that dominant factors responsible for sediment erosion were deglaciation and Indian Summer Monsoon derived precipitation in the headwaters despite the presence of a geomorphic barrier (the deep, narrow gorge).

    Significance of the study

    • The scientists have traced where the rivers draining Himalaya and its foreland erode the most and identify the zones that receive these eroded sediments and fill up.
    • The study will help understand river-borne erosion and sedimentation, which are the main drivers that make large riverine plains, terraces, and deltas that eventually become the cradle to evolving civilizations.
    • It will also help study the dynamics of devastating floods created by these Himalayan rivers in recent times.
    • Thus, the understanding of water and sediment routing becomes crucial while developing infrastructure and for other development works in the river catchment area.

  • Ganga water improves during lockdown

    The Ganga water quality has improved remarkably during the lockdown period. This highlights the importance of synergy for absolute symbiosis between nature and man as the need of the hour.

    Context

    • The novel coronavirus lockdown (COVID-19) pandemic has put millions in the throes of adversity — and yet, there is a reason to celebrate.
    • Over a month into the nationwide lockdown, air and water pollution levels have shrunk and the wildlife is free.
    • Of 36 monitoring units placed in the Ganga, water quality at 27 points was found suitable for bathing and propagation of wildlife and fisheries in the lockdown period

    Status of rivers in India

    • India’s water bodies are in a poor state. The rivers are becoming dumpyard for untreated sewage and industrial waste.
    • In the name of economic growth, most rivers and streams have been turned into sewer canals and are getting difficult to be treated.
    • It is estimated that every day, almost 40 million litres of wastewater enters rivers and other water bodies; only 37 per cent is adequately treated.
    • A Centre Pollution Control Board (CPCB) report showed that critically polluted river stretches in the country have increased from 302 stretches in 2016 to 351 stretches in 2018.
    • The finding was based on Biological Oxygen Demand (BOD).

    Ganga

    • According to CPCB, more than half of wastewater treatment plants in the basin do not comply with the discharge norms.
    • Since 1985, several programmes and schemes have been launched to clean the Ganga. It began with the Ganga Action Plan I, followed by Ganga Action Plan II.

    • In 2015, the biggest-ever initiative, Namami Gange was launched with a budget of over Rs 20,000.
    • Despite numerous programmes and huge funds, the Ganga still runs polluted.

    The causes

    • More than 80 per cent of pollution in the Ganga is due to domestic sewage from surrounding towns and villages. The rest is contributed by industrial waste.
    • During the lockdown, domestic sewage would have increased owing to increased demand for water to maintain hand-washing hygiene. Industrial waste, however, stopped entering the Ganga.
    • Other activities such as tourism, fairs, bathing and cloth washing near the ghats were curtailed. Experts said these observations reflected that domestic sewerage was not the only cause of concern.
    • When sewage is mixed with industrial effluents, it gets difficult for the river to assimilate pollution.
    • One more reason was high number of western disturbances which brought rain and improved the flow in the river leading to dilution.

    COVID-19’s gift to Ganga

    • After the nationwide lockdown was imposed, within 10 days signs of improvement in water quality started surfacing.
    • At Varanasi’s Nagwa Nala, the Dissolved Oxygen (DO) values were found increased to 6.8 milligram/litre against 3.8 mg/l on March 6, showcasing an extraordinary improvement of 79 per cent in DO values.
    • 30 per cent of the total BOD load was due to industries along the river, which amounted to 130-150 tons per day.
    • Since all major polluting industries are closed, the toxic load is off the river.

    Surprisingly better

    • Ganga water at Haridwar and Rishikesh was reported fit for drinking due to 500 per cent decrease in sewage and industrial effluents.
    • A dip in the number of visitors at ghats in Haridwar also helped the river water quality.
    • The Ganga water has become fit for ‘achaman’, which means ritual sipping, after a long time.

    Bringing the ambitions to reality

    There is an urgent need to:

    • Reinvestigate the main source of pollution in Ganga and reorient all river cleaning policies and programmes based on lockdown findings.
    • Industries need to strictly adhere to discharge norms accompanied with strong enforcement of laws and regulations vis-a-vis strong monitoring and vigilance framework.
    • Setting up of effective interventions to clean rivers, reliable, representative and comprehensive data collected at high frequency in a disaggregated manner.
    • There is an urgent need to expand the network of monitoring stations on the Ganga, the Yamuna and tributaries of Ganga in more places.
    • Over-extraction and over-exploitation of Ganga’s waters have rendered long stretches of the river completely dry for much of the year. There is a need to maintain ecological flow to keep it clean for longer run.
    • Education and awareness needs to be carried out strategically.

    Back2Basics: Biochemical Oxygen Demand

    • BOD is the amount of dissolved oxygen needed (i.e. demanded) by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period.
    • The BOD value is most commonly expressed in milligrams of oxygen consumed per litre of sample during 5 days of incubation at 20 °C and is often used as a surrogate of the degree of organic pollution of water.
    • BOD is similar in function to chemical oxygen demand (COD), in that both measure the amount of organic compounds in water.
    • However, COD is less specific, since it measures everything that can be chemically oxidized, rather than just levels of biodegradable organic matter.

  • [pib] Petersberg Climate Dialogue

    India along with 30 countries deliberated on issues of Climate Change in first-ever virtual Petersberg Climate Dialogue.

    Climate change negotiations are somehow put to a halt due to ongoing pandemic. Such small dialogues are keeping alive the spirit of climate action.

    Petersberg Climate Dialogue

    • It has been hosted by Germany since 2010 to provide a forum for informal high-level political discussions, focusing both on international climate negotiations and the advancement of climate action.
    • This year’s virtual Dialogue was co-chaired by Germany and the UK.
    • The dialogue was crucial because of the efforts to contain coronavirus as well as countries preparing to move into the implementation phase of the Paris Agreement 2015 in the post-2020 period.

    India’s Contributions

    • Expressing solidarity with the world as it combats the COVID 19 pandemic the Union Minister highlighted how COVID – 19 has noticed that we can survive on less.
    • India pushed for having climate technology as an open source available to all countries at affordable prices.
    • India stressed on climate finance and urged to plan for 1 trillion USD in grants to the developing world immediately.
    • India focussed on the opportunity that the world has today to accelerate renewable energy deployment and creating new green jobs in the renewable energy and energy efficiency sector.

  • New list of names of tropical cyclones over north Indian Ocean

    The India Meteorological Department (IMD) has released a new list containing 169 names of future tropical cyclones that would emerge in the Bay of Bengal and the Arabian Sea.

    When is the name of a Tropical Cyclone declared?

    • Names are declared when TCs are diagnosed with maximum sustained surface wind-speed of 34 knots (62 kmph) or more as per Global Data Processing and Forecasting System (GDPFS) Manual of WMO.
    • Panel Members’ names will be listed alphabetically country-wise.

    We can expect a statement based prelim question like – Which of the following criterion are followed while naming a tropical cyclone?

    Who is involved in the naming of Tropic Cyclone?

    • Worldwide there are six regional specialised meteorological centres (RSMCs) and five regional Tropical Cyclone Warning Centres (TCWCs) mandated for issuing advisories and naming of tropical cyclones.
    • IMD is one of the six RSMCs to provide tropical cyclone and storm surge advisories to 13 member countries under WMO/ESCAP Panel.
    • The panel countries include Bangladesh, India, Iran, Maldives, Myanmar, Oman, Pakistan, Qatar, Saudi Arabia, Sri Lanka, Thailand, United Arab Emirates and Yemen.
    • RSMC, New Delhi is also mandated to name the Tropical Cyclones developing over the North Indian Ocean (NIO) including the Bay of Bengal and the Arabian Sea.

    Since when did naming begin?

    • The WMO/ESCAP Panel on Tropical Cyclones (PTC) at its twenty-seventh Session held in 2000 in Muscat, agreed in principle to assign names to the tropical cyclones in the Bay of Bengal and the Arabian Sea.
    • After long deliberations among the member countries, the naming of the tropical cyclones over the north Indian Ocean commenced from September 2004.
    • This list contained names proposed by the eight member countries of WMO/ESCAP PTC, viz., Bangladesh, India, Maldives, Myanmar, Oman, Pakistan, Sri Lanka and Thailand.

    Why name Cyclones?

    The naming of Tropical Cyclones (TC) helps the scientific community, disaster managers, media and general masses to-

    • identify each individual cyclone.
    • create awareness of its development.
    • remove confusion in case of simultaneous occurrence of TCs over a region
    • remember a TC easily
    • rapidly and effectively disseminate warnings to a much wider audience

    Major criteria adopted for naming

    • The proposed name should be neutral to (a) politics and political figures (b) religious believes, (c) cultures and (d) gender
    • The name should be chosen in such a way that it does not hurt the sentiments of any group of the population over the globe
    • It should not be very rude and cruel in nature
    • The maximum length of the name will be eight letters
    • The Panel reserves the right to reject any name if any of the criteria above are not satisfied
    • The names of tropical cyclones over the north Indian Ocean will not be repeated. Once used, it will cease to be used again.

    Back2Basics

    https://www.civilsdaily.com/news/explained-naming-of-cyclones/

  • How the ozone layer hole over Arctic closed?

    Recently the EU’s Copernicus Atmosphere Monitoring Service (CAMS) announced that a hole in the Arctic ozone layer, believed to be the biggest reported, has closed.

    What healed the hole in the Ozone?

    • The ozone hole’s closing was because of a phenomenon called the polar vortex, and not because of reduced pollution levels due to Covid-19 lockdowns around the world.
    • The hole in the North Pole’s ozone layer, which was first detected in February, had since reached a maximum extension of around 1 million sq km.

    Ozone hole

    • The ‘ozone hole’ is not really a hole — it refers to a region in the stratosphere where the concentration of ozone becomes extremely low in certain months.
    • Ozone, made up of three oxygen atoms, occurs naturally in small amounts.
    • Roughly 10 km to 40 km up in the atmosphere (the layer called the stratosphere), the ozone layer is sunscreen, shielding Earth from harmful ultraviolet radiation.
    • Manufactured chemicals deplete the ozone layer. Each spring over Antarctica (it now springs there), atmospheric ozone is destroyed by chemical processes.
    • This creates the ozone hole, which occurs because of special meteorological and chemical conditions that exist in that region.

    The importance of the ozone layer

    • Ozone (chemically O3, a molecule of three oxygen atoms) is found mainly in the upper atmosphere, an area called the stratosphere, between 10 and 50 km from the earth’s surface.
    • Though it is talked of as a layer, ozone is present in the atmosphere in rather low concentrations.
    • Even at places where this layer is thickest, there are not more than a few molecules of ozone for every million air molecules.
    • They perform a very important function. By absorbing the harmful ultraviolet radiations from the sun, the ozone molecules eliminate a big threat to life forms on earth.
    • UV rays can cause skin cancer and other diseases and deformities in plants and animals.

    Why this year’s hole was massive?

    • This year, the ozone depletion over the Arctic was much larger.
    • Scientists believe that unusual atmospheric conditions, including freezing temperatures in the stratosphere, were responsible.
    • Cold temperatures (below -80°C), sunlight, wind fields and substances such as chlorofluorocarbons (CFCs) were responsible for the degradation of the Arctic ozone layer.
    • Although Arctic temperatures do not usually fall as low as in Antarctica, this year, powerful winds flowing around the North Pole trapped cold air within what is known as the polar vortex.
    • By the end of the polar winter, the first sunlight over the North Pole initiated this unusually strong ozone depletion—causing the hole to form.

    How long it will take for complete recovery?

    • As per the Scientific Assessment of Ozone Depletion data of 2018, the ozone layer in parts of the stratosphere has recovered at a rate of 1-3 per cent per decade since 2000.
    • At these projected rates, the Northern Hemisphere and mid-latitude ozone is predicted to recover by around 2030, followed by the Southern Hemisphere around 2050, and polar regions by 2060.

    Also read: Polar Vortex

    https://www.civilsdaily.com/news/whats-causing-extreme-cold-in-us-midwest/

  • Rohtang Pass and its location

    The Border Roads Organisation (BRO) has opened the Rohtang Pass, three weeks in advance, for transporting essential supplies and relief materials to Lahaul and Spiti districts of Himachal Pradesh.

     Rohtang Pass

    • It is a high mountain pass (elevation 3,980 m) on the eastern Pir Panjal Range of the Himalayas around 51 km from Manali.
    • It connects the Kullu Valley with the Lahaul and Spiti Valleys of Himachal Pradesh, India.
    • The pass lies on the watershed between the Chenab and Beas basins.
    • On the southern side of this pass, the Beas River emerges from underground and flows southward and on its northern side, the Chandra River, a source stream of the river Chenab, flows westward.

    Another pass in new:

    https://www.civilsdaily.com/news/sela-pass-tunnel-project/

  • [pib] Species in news:  Anthurium

    A women innovator from Thiruvananthapuram, Kerala, has developed ten varieties of Anthurium, a flower with high market value, by cross-pollination.

    Anthurium

    • An anthurium is a vast group of beautiful blooming plants available in a wide range of colours.
    • Anthurium is one of the best domestic flowering plants in the world.
    • They are decorative as well as purify the surrounding air and remove harmful airborne chemicals like formaldehyde, ammonia, toluene, xylene, and allergens.
    • Its importance of removing toxic substances from the air, NASA has placed it in the list of air purifier plants.
    • Anthurium has larger economic importance because of its eye-catching and beautiful inflorescence and fetches a good market price.

    Salient features of the Anthurium varieties are

    • Large beautiful flowers
    • Different colors of spathe and spadix
    • Long stalks
    • Better shelf life
    • Good market value

  • Earth Day 2020 and its significance

    Yesterday, April 22nd was celebrated as Earth Day, an international event celebrated around the world to pledge support for environmental protection.

    The Earth Day designation by UN and its first observance have confusing difference. Make note of that. We can expect a question based on that. Also read about Earth Overshoot Day.

    What is Earth Day?

    • In 2009, the United Nations designated April 22 as ‘International Mother Earth Day’.
    • Earth Day aims to “build the world’s largest environmental movement to drive transformative change for people and the planet.”
    • Earth Day was first observed in 1970, when 20 million took to the streets to protest against environmental degradation.
    • The event was triggered by the 1969 Santa Barbara oil spill, as well as other issues such as smog and polluted rivers.
    • The landmark Paris Agreement, which brings almost 200 countries together in setting a common target to reduce global greenhouse emissions, was signed on Earth Day 2016.

    Significance of this year

    • The year 2020 marks the 50th anniversary of the annual celebrations.
    • This year’s theme for Earth Day is ‘climate action’.

  • Daporijo Bridge and its significance

    A key bridge over the Subansiri River in Arunachal Pradesh close to the Line of Actual Control (LAC) was constructed by the Border Roads Organisation (BRO) in record 27 days.

    North-East has seen the construction of a series of bridges by BRO in recent times post-Doklam standoff. Make a note of all such bridges and the corresponding rivers over which they are built.

     Daporijo Bridge

    • This Bridge is one of the two over River Subansiri which connect Daporji in North Subansiri dist. with rest of state.
    • This and the other bridge at Tamin sustaining more than 600 villages and troops strength of around 3000 personnel manning the LAC which includes disputed Areas of Asaphila and Maza.
    • All supplies, rations, constructional material and medicines pass over this bridge.
    • The new bridge now can withstand 40 tonnes of weight allowing a safe passage for heavier vehicles catering for the requirements of the Indian Army as well as future infrastructure development requirements.

    Significance

    • India has speeded up the construction of critical infrastructure in its northeast in the past half a dozen years including airports, railways and roads with an eye on China that has motorable roads right up to the border.
    • Arunachal Pradesh was the scene of the 1962 India-China border conflict that ended badly for India. China on its parts claims all of the state as “Southern Tibet.”
    • Of the 3488 km long Line of Actual Control with China 1126 lies with Arunachal Pradesh alone.
    • The two countries are yet to demarcate their border with the two sides patrolling the LAC but reporting incursions by the other side since the frontier is not clearly marked.

  • Matterhorn Mountain of the Swiss Alps

    Switzerland has expressed solidarity with India in its fight against the coronavirus pandemic by projecting the tricolour on the famous Matterhorn Mountain in the Swiss Alps.

    It has been long time since a question on global mountains/mountain ranges has not been asked in the prelims. Gear up for the uncertainty. Make a special sheet of geographical locations in news.

    Mt. Matterhorn

    • The Matterhorn is a mountain of the Alps, separating the main watershed and border between Switzerland and Italy.
    • It is a large, near-symmetric pyramidal peak in the extended Monte Rosa area of the Pennine Alps, whose summit is 4,478 metres.
    • It is one of the highest summits in the Alps and Europe (Mont Blanc being highest).
    • The four steep faces, rising above the surrounding glaciers, face the four compass points and are split by the Hörnli, Furggen, Leone/Lion, and Zmutt ridges.

    Its formation

    • The Matterhorn is mainly composed of gneisses originally fragments of the African Plate before the Alpine orogeny.
    • The mountain’s current shape is the result of cirque erosion due to multiple glaciers diverging from the peak, such as the Matterhorn Glacier at the base of the north face.

    Back2Basics: Alps mountain range

    • The Alps are the highest and most extensive mountain range system that lies entirely in Europe.
    • It stretches approximately 1,200 kilometres across eight Alpine countries (from west to east): France, Switzerland, Monaco, Italy, Liechtenstein, Austria, Germany, and Slovenia.
    • The mountains were formed over tens of millions of years as the African and Eurasian tectonic plates collided.
    • Extreme shortening caused by the event resulted in marine sedimentary rocks rising by thrusting and folding into high mountain peaks such as Mont Blanc and the Matterhorn.
    • Mont Blanc spans the French–Italian border, and at 4,809 m (15,778 ft) is the highest mountain in the Alps.