What’s in today’s article?

• Why in News?
• Key highlights of the study by ISRO
• What are Glacial lakes?
• Use of remote-sensing technology to monitor glacial lakes
• Mitigation of risks posed by glacial lakes

Why in News?

Recently, the Indian Space Research Organisation (ISRO) released satellite-data-based analysis on the expansion of glacial lakes in the catchments of Indian Himalayan River basins.

This is the latest among a series of studies on glacial lakes that have highlighted the risks of glacial lake outburst floods (GLOFs), and their impact on infrastructure and settlements downstream of such lakes.

Key highlights of the study by ISRO

• The study
• ISRO’s analysis looked at satellite data archives spanning the past four decades to assess changes in the glaciated environment.
• Long-term satellite imagery covering the catchments of Indian Himalayan River basins — spread over India, Nepal, Tibet, and Bhutan — is available from 1984 onwards, till 2023.
• Findings
• ISRO’s data has indicated significant expansion in the size of glacial lakes.
• Of the 2,431 lakes larger than 10 hectares (identified during 2016-17), 676 glacial lakes had expanded significantly since 1984.
• ISRO said that 130 of the 676 lakes are situated in India, in the Indus (65), Ganga (7), and Brahmaputra (58) river basins.
• These lakes have expanded as glaciers are retreating at an ever-faster rate due to global warming.

What are Glacial lakes?

• About
  • Glacial lakes are bodies of water that form in depressions or basins created by the erosive action of glaciers.
  • These lakes are typically found in regions where glaciers have previously existed or are currently present.
  • Glacial lakes vary in size and shape, ranging from small ponds to large, deep bodies of water.
  • ISRO categorised glacial lakes into four broad categories based on how they were formed — moraine-dammed, ice-dammed, erosion-based, and ‘others’.
  • Glacial lakes are crucial sources of freshwater for rivers.
  • However, they also pose significant risks, specifically of Glacial Lake Outburst Floods (GLOFs).
    • GLOFs occur when glacial lakes release large volumes of meltwater due to the failure of natural dams, resulting in sudden and severe flooding downstream.
• Formation
  • Glacial Erosion: 
    • Glaciers are massive bodies of ice that move slowly over the landscape, eroding and shaping the underlying bedrock through processes such as abrasion and plucking. 
    • As glaciers advance, they carve out deep valleys and basins in the landscape.
  • Deposition of Glacial Moraines
    • As glaciers move, they carry vast amounts of sediment and debris, including rocks, gravel, and sand.
    • When glaciers retreat or melt, they deposit this material at their edges, forming features called moraines.
    • Moraines can act as natural dams, blocking the flow of water and creating depressions where glacial lakes can form.
  • Melting Ice
    • As temperatures rise or glaciers retreat, the ice within the glacier melts, filling the depressions created by glacial erosion with water.
    • This water collects in the basins, forming glacial lakes.
  • Terminal Moraine Formation
    • In some cases, glaciers deposit large ridges of sediment and debris at their terminus, creating natural dams that impound water and form glacial lakes behind them. These lakes are called terminal moraine lakes.

Use of Remote-Sensing Technology to Monitor Glacial Lakes

• The monitoring of glacial lakes and their expansion in the Himalayan region is challenging due to the rugged terrain.
• This is where satellite remote-sensing technology proves to be an excellent tool.
• Analyzing changes in glacial lakes using satellite data helps us understand how these lakes are changing over time.
• This information is crucial for figuring out how they affect the environment and for creating plans to manage the risks of glacial lake outburst floods and adapt to climate change in areas with glaciers.

Mitigation of Risks posed by Glacial Lakes

• As per one study, lowering of the lake levels by 10 to 30 m significantly reduces the impacts on downward towns.
  • Although it does not completely eliminate the risks posed by a GLOM event.
• One way to syphon off lake water is by using long High-Density Polyethylene (HDPE) pipes.
• In 2016, members of the Sikkim State Disaster Management Authority used this method to reduce water levels in Sikkim’s South Lhonak Lake.

Q.1. What is Indian Space Research Organisation (ISRO)?

The Indian Space Research Organisation (ISRO) is India's national research organization, founded on August 15, 1969 by Vikram Sarabhai. ISRO's headquarters are in Bengaluru and its parent organization is the Department of Space.

Q.2. What is remote sensing?

Remote sensing is the process of collecting data about an object or location without making physical contact with it. It's a type of geospatial technology that uses aircraft-based and satellite-based sensors to detect and monitor the physical characteristics of an area by measuring its reflected and emitted radiation at a distance.

Source: How ISRO used satellite remote-sensing to analyse glacial lakes in Himalayas

What’s in today’s article?

• Why in News?
• A Timeline of Introduction of VVPATs in India
• What Have Been the Legal Cases Surrounding the VVPAT?
• What was the Recent VVPAT-EVM Tally Case?
• What has SC Ruled in the VVPAT-EVM Tally Case?

Why in News?

• The Supreme Court rejected the demand for 100% verification of Voter Verified Paper Audit Trails (VVPATs) in Indian elections.
• The SC also rejected a return to the earlier ballot paper system for elections - something which opposition parties demanded in recent years.

A Timeline of Introduction of VVPATs in India

• The idea of the VVPAT machine first emerged in 2010, when the Election Commission of India (ECI), held a meeting with political parties to discuss how to make the EVM-based polling process more transparent.
• After a prototype was prepared, field trials were held in Ladakh, Thiruvananthapuram, Cherrapunjee, East Delhi, and Jaisalmer in 2011.
• After fine-tuning the design, holding more trials, and taking feedback from political parties, an ECI expert committee approved the design in 2013.
• In 2013, the Conduct of Elections Rules 1961 were amended to allow for a printer with a drop box to be attached to the EVM.
• The VVPAT was used for the first time in all 21 polling stations of the Noksen Assembly constituency of Nagaland in 2013.
• After this, the ECI decided to introduce VVPATs in a phased manner and by (June) 2017, there was 100% adoption of VVPATs.
• In 2018, the ECI asked the Indian Statistical Institute (ISI) to come up with a mathematically sound and practically cogent sample size for the internal audit of the VVPAT slips with electronic result of EVMs.
• On the basis of which, the ECI mandated the counting of VVPAT slips of one randomly selected polling station per Assembly constituency.
• This was increased to five polling stations per Assembly seat, following a SC judgement in 2019.
• The five polling stations are selected by a draw of lots by the Returning Officer concerned, in the presence of candidates/ their agents.

What Have Been the Legal Cases Surrounding the VVPAT?

• Subramanian Swamy vs ECI (2013): TheSC ruled that a paper trail was indispensable for free and fair elections, and ordered the government to provide funding for the roll-out of VVPATs.
• Chandrababu Naidu Case (2019):
  • He moved the SC asking for a minimum 50% randomised VVPAT slips to be counted.
  • However, the ECI argued that this would delay the election results by five to six days, as it takes about an hour for election officers to match VVPAT slips with the EVM count in one polling station.
  • The EC has also highlighted infrastructure challenges, including the availability of manpower, as obstacles to increasing the number of polling booths where VVPAT slips are counted.
  • Opposition parties argue that the sanctity of a fair election outweighs the concern of delay in the declaration of results.
  • The court ordered the EC to count VVPATS in five polling stations instead.

What was the Recent VVPAT-EVM Tally Case?

• In 2023, the ADR had filed a petition before the apex court saying that to ensure free and fair elections, the tally from Electronic Voting Machines (EVMs)/ data on votes cast, should be cross-verified with the VVPATs.
  • The petition (along with other petitions) seeks 100% verification of votes cast on EVMs using the VVPAT.
• To make sure that this process is carried out as fast as possible, ADR suggested the use of barcodes on VVPAT slips.

What has SC Ruled in the VVPAT-EVM Tally Case?

• The SC rejected the demand for 100% verification of VVPATs in Indian elections and also rejected a return to the earlier ballot paper system for elections, thus reposing faith in the electoral process.
• However, the court issued two directions and some suggestions to the ECI in this regard, attempting to ensure that India’s electoral process remains full proof.
• First direction:
  • In a first, the court gave directions to the ECI to seal and store the symbol loading units (SLUs) for 45 days after declaration of results.
  • SLUs are memory units that are first connected to a computer to load election symbols onto it, and then used to enter symbols of the candidates on the VVPAT machines.
• Second direction:
  • The SC has enabled candidates to seek verification of the EVMs - again a first.
  • The burnt memory in the EVM microcontroller must be checked by a team of engineers - after results are declared - if candidates (placed 2nd and 3rd in the election) make such a request within 7 days of declaration of results.
  • The expenses for this verification will have to be borne by the candidate and which would be refunded in case the EVM is found to be tampered with.
• Suggestion on VVPAT:
  • The ECI may examine the suggestion that VVPAT slips can be counted using a counting machine, rather than by humans.
  • VVPAT slips could have a barcode printed on them, making it easier for machine counting.

Q.1. How do EVMs work?

An EVM has two units - the control unit and the balloting unit. These are connected by a cable. The EVM's control unit is with the presiding officer, also known as polling officer. The balloting unit is kept in the voting compartment, where people cast their votes.

Q.2. What were VVPATs introduced?

The Voter Verified Paper Audit Trail (VVPAT) allows the voter to cross-check whether his/her vote was cast properly and went to the right candidate or not.