[Feb]Glacial lake outburst flood,Chamoli,UK

Question 1

How glacial lakes are formed?

Answer 1

In himalaya -> glaciers are present.Whenever the glaciers melt & water is accumulated in depression nearby ->glacial lakes are formed.

Natural barriers present around the lakes in form of sediments-> will protect glacial lakes

Question 2

What is glacial lake outburst flood(GLOF)?

Answer 2

2 ways this can happen

1. When water inside breaks the natural barrier of sediments -> flood comes -> it’s called glacial lake outburst flood
2. No breach of walls-> but when glacial lake is excessively melting in that region becuase of climate change/rainfall/etc.-> water in lake crosses capacity of lake to hold water-> lake overflow ->AKA glacial lake outburst flood

Question 3

Possible Natural causes of GLOF?

Answer 3

-landslide/earthquake/avalanche ->natural boundaries of lake can get broken->GLOF

Global warming-> high temp->more water ->GLOF

Question 4

Possible Human causes of GLOF?

Answer 4

High population -> need water for drinking ,irrigation,electricity;area for living,raw material for industries etc.->dam construction,deforestation,mining activities -> might create instability -> GLOF

Question 5

Major concerns due to this?

Answer 5

excessive flooding in downstream area

• Rishiganga hydroelectric project & Tapovan hydroelectric project on Dhauliganga river impacted[Mapping]
• 200 MW of power supply to national grid is affected

Question 6

What should be done?

Answer 6

• Continuous mapping & recording status of glacial lake to check increased water levels
• Educating community about risk of living near glacial lakes
• Early warning system to alert disaster management officials/authorities
• Better land planning -> No dam/mining/deforestation in seismic region

Question 7

Vulnerability of Uttarakhand?

Answer 7

-Uttarakhand is located in the region of the young and unstable Himalayas. It is also subject to intense rainfall.