Topic - UTTARAKHAND GLACIER DISASTER 1
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GEOGRAPHY NEWSLETTER 01 A Fortnightly Iniave! By Himanshu Sir Topic - UTTARAKHAND GLACIER DISASTER 1. What : A glacial breakage at the Ron peak triggered flash floods in Chamoli district on February 7, in which two dams, 12 km apart, were destroyed within 20 minutes. [Owing to SNOWBALL EFFECT]. A Trail of Destrucon! “Turn of EVENTS” A Point to Note: Chamoli recorded no extreme rainfall before the flash floods. According to IMD, Chamoli received 26 per cent less rainfall than normal between January 1 and February 7. No major seismic acvity was recorded during the period. A Reminder! Kedarnath flash floods, 2013: in which around 6,000 people died and 200,000 pilgrims were trapped. That me, too, roads and bridges got washed away in the neighbouring Rudraprayag district aer the moraine (a mass of rocks and sediment carried by glaciers) holding the waters of Chorabari glacial lake exploded following 72 hours of rain and a cloud burst. 2. What was done to ascertain the CAUSE: Agencies conducted field and aerial surveys, analysed satellite imagery and submied a preliminary report to the government, saying the disaster has been caused by rock avalanche. 3. What caused the glacial break that triggered the Chamoli flash floods: A Rock Avalanche That Fell In The Rishiganga Caused The Flash Flood. The Rock Avalanche Was Caused Due To Breaking Of A Glacier. But There Is No Consensus On What Caused The Glacier To Break 01 011-45586829, 9718793363 website: www.guidanceias.com 4. View-Points put forward for the GLACIER BREAK-OFF? Few hypotheses were postulated: View-Point #1: The hanging glacier was lying over a highly weathered mica (a highly foliated medium-grade metamorphic rock). Due to temperature fluctuaons, such rock masses somemes go through thawing and refreezing and develop small cracks. Rainwater might have percolated into these cracks and freezed up, increasing in volume and exerng pressure from within. This glacier rock mass might have gone through such thawing and refreezing in geological me, eventually becoming so weak that it fell due to gravity. View-Point #2: The hanging glacier might have reached a crical stage over a period of me where any small factor toppled it over. It could have been wind or even snowfall. Before the event, on February 3-4, there was some snowfall in the region. It might have accumulated and added weight to the glacier which was already placed on a highly-weathered rock mass. View-Point #3: Points at rising temperatures. Just before the event, temperatures in the region were unusually high. Snow might have melted and percolated through the mica's fractured path, making the overlaying rock mass slippery. Such rising temperatures could have played a significant role in the rock avalanche. The glacial ice could have melted to form liquid water and then destabilise the rock, and even lubricate the bedrock, thereby contribung to its failure. Some Stascs to Jusfy! Climate change has driven errac weather paerns like increased snowfall and rainfall, warmer winters have led to the melng of a lot of snow. .. The thermal profile of ice has been increasing. Earlier, the temperature of ice ranged from -6°C to -20°C and now it is -2°C, making it more suscepble to melng. .. The average temperature in the northwestern Himalaya has risen by 0.66°C since 1991 (an increase much higher than the global average). .. The higher Himalaya became even warmer on average in the same period. Several other studies also indicate that glacial melng are becoming frequent in a warming world. Climate change has an indirect effect on landslides occurring at high altudes by degrading permafrost and melng glaciers, which may increase magnitude and frequency of landslides”. For example: The Hindu Kush Himalaya Assessment Report (2019): had pointed out that one-third of the Hindu Kush Himalaya's glaciers would melt by 2100. It may happen even if all the countries in the region fulfilled their commitments under the Paris Agreement. 02 011-45586829, 9718793363 website: www.guidanceias.com Other View-Points: Ø Experts also opine that massive deforestaon is a possible reason for the disaster. For example, in 2014, the Chopra commiee established that the haphazard construcon of dams can cause irreversible damage to the region. Ø There are also possibilies that the use of explosives in the construcon of dams and other infrastructure would have weakened the rock strata. Are Dams a feasible opon in Fragile Himalayan Ecological System? The Himalayan ecosystem is in a constant state of flux and are naturally primed for calamies. According to a study, Uarakhand has faced 27 major landslide events between 1880 and 2015, one-third of which have occurred in just 15 years—between 2001 and 2015. This can be seen in the valleys in the Garhwal Himalayas that are drained by the Alaknanda and the Bhagirathi river systems. The snow-clad Chaukhamba range, from where these rivers emerge, consists of enormous glaciers. PECULIAR CHARACTERISTICS OF HIMALAYAS Youngest Highly mountain prone to range erosion In higher reaches of catchment areas Due to connuous upliment the ground is made of unconsolidated of the mountain the region PECULIAR moraine which greatly helps in the falls in a very high seismic CHARACTERISTICS formaon of landslides. As they move zone (seismic zone V) and its downstream, they hit the corners of the rivers cut the rocks deeply valley and cause a lot more damage to surrounding areas. If the river has a high gradient, the boulders rack up more strength and cause more damage”. Bank erosion is also extensive wherever the Higher rivers take a Himalayas sinuous course Rainstorms and cloud also do not bursts are have vegetaon very common 03 011-45586829, 9718793363 website: www.guidanceias.com Thus, Hydropower projects must be weighed against their benefits and challenges: Ø Re-Thinking HydroPower Opon: IPCC report has assessed that the climate crisis has altered the frequency and magnitude of the natural hazards in high mountain regions of the world. In this respect, adherence to the Chopra Commiee recommendaons, which studied the impact of receding glaciers on hydroelectric power projects (HEPs) and objected to the construcon of HEPs in paraglacial regions (between 2,200 to 2,500 meters above the sea level) is of utmost importance. Ø Miscalculaon of life of dams: There is also some evidence that the life of dams is oen exaggerated, and siltaon, which reduces it, is grossly underesmated: in the Bhakra dam in Himachal Pradesh, for instance, siltaon was higher by 140% than calculated. According to the South Asia Network on Dams, Rivers and People, a think tank, under construcon HEPs threaten about 50% of the Dhauliganga's length. The need is to rigorously study the impact of policy on the Himalayas and confine Hydroprojects to those with the least impact, while relying more on low impact run- of-the-river power projects that need no destrucve large dams and reservoirs. Ø Apart from this, other alternaves like solar energy, wind energy should be pursued as the green growth model of development. Ø Red flags have been raised repeatedly, parcularly aer the moderate quake in 1991 in the region where the Tehri dam was built and the 2013 floods that devastated Kedarnath, poinng to the threat from dam-induced microseismicity. Ambious Char Dham Project: Widening the roads can prove detrimental! The Chamoli flash floods hove once again fumed the spotlight on the Union government's ambious Char Dham Naonal Highway project. Stretching 899-km, the project is to connect the Hindu pilgrimage sites of Badrinath, Kedarnath, Gangotri and Yomunotri in the Garhwal Himalayas of Uarakhand. .. The project will convert the highways into two lanes with 12 bypass roads, 15 big flyovers, 101 small bridges, 3,596 culverts and two tunnels, it will widen the roads by at least 10 m and make them all-weather. All this acvity will destabilise hill slopes. Felling of trees and the reverberaons from the construcon will cause disturbance of glaciers like the one involved in Chamoli flash floods. .. Issues in EIA: The exact ecological impact of the Char Dham project is difficult to assess as there has been no Environment Impact Assessment (EIA) of the project as a whole. Ghatak says the government got around the EIA process by claiming that the project is actually a combinaon of 53 smaller projects, each less than 100 km long as such projects do not require EIA. 04 011-45586829, 9718793363 website: www.guidanceias.com GUIDANCE IAS MORE THAN A COACHING GEOGRAPHY (OPT.) CLASSROOM PROGRAMME Stage: 1 7 14 21 28 4 11 18 21 at 4:00 Geography (Opt.) Tool & Techniques: Mar Mar Mar Mar Apr Apr Apr Apr PM Stage: 2 Preparatory Course (NCERTs) : 26 APRIL 2021 (Available in Our YouTube Channel) Most Comprehensive Coverage from Stage: 3 MAINS Course : 05 JULY 2021 NCERT's to Mains Syllabus GEOGRAPHY (OPT.) 500+ Programme: JULY 2021 (ONLINE/OFFLINE) Access Videos upto Mains 2021 Geography (opt.) 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