GL 6 Flashcards
What does GLOF stand for, what is it
Glacial lake outburst flood.
Lake flows over moraine
Triggers of GLOFS
Wave generation:
Glacier calving, icefall, avalanches, rapid input of meltwater, seismic activity
Dam failure:
Large lake volume, low point in dam wall, melting of buried ice in moraine structure, seismic activity
How may climate change impact GLOFs
Increase meltwater, calving, icefall, melting of buried ice
LAKE LOWERING
Where is Bhutan?
Mountainous, undeveloped area in eastern Himalayas
LAKE LOWERING
What Glacial lakes is Bhutan threatened by?
25 potentially dangerous
Lake Thorthormi
LAKE LOWERING
What would happen if a GLOF happened in Bhutan
53million cubic meters of water released
362 people impacted
Fertile ground submerged
Three hydro power projects destroyed
LAKE LOWERING
How do Glacial meltwaters benefit people in Bhutan
Irrigation, drinking water, hydroelectricity
LAKE LOWERING
How many people were killed in 1994 Lugge Tsho GLOF. What was the economic impacts of this
24
Caused millions of dollars in damage
LAKE LOWERING
What is the aim of lake lowering
Reduce volume of lake
LAKE LOWERING
What are the benefits of lake lowering
Reduces risk of GLOF
employs 350 workers, 5x higher wage
Employ herdsmen
LAKE LOWERING
What factors impact lake lowering in Bhutan
9 day trek - remote
lack of healthcare - 3 died
equipment - work done manually
extreme weather means work can only be done 3-4 months a year
LAKE LOWERING
How does Bhutan overcome difficulties
Use local mules - investment in local herdsmen
LAKE LOWERING
Can Lake lowering always be done?
No - Sikkam, North East India - 2023
Over 100 people missing
Intense monsoonal rain
Lack of funding, money is spent elsewhere
CONSTRUCTION OF RESERVOIRS
What is a reservoir
What are artificial reservoirs made from
Large natural or artificial lake used as a source of water supply
Artificial reservoirs are made from dams
CONSTRUCTION OF RESERVOIRS
Arguments for construction of artificial reservoirs
Water supple and security
Hydroelectricity
Flood control
Economic benefits
CONSTRUCTION OF RESERVOIRS
Arguments against construction of artificial reservoirs
Environmental impact
Ruins landscape (AoNB)
Culture and heritage
High costs and long term viability
Erosion and accumulation of sediment
CONSTRUCTION OF RESERVOIRS
Where is the Elan Valley
When was the reservoir built?
Wales
1893 and 1904
CONSTRUCTION OF RESERVOIRS
What does the Elan Valley reservoir do
Supplies water to Birmingham (aquifers)
Welsh water -> seven Trent water
CONSTRUCTION OF RESERVOIRS
Why was the Elan valley chosen for reservoirs
High levels of rainfall
CONSTRUCTION OF RESERVOIRS
What are the negatives of Elan valley reservoir
Over 100 people were relocated
Buildings and agricultural lands flooded
CONSTRUCTION OF RESERVOIRS
What are the positives of Elan valley reservoir
Reliable, clean drinking water to Birmingham
Tourism
Environmental protection
Hydroelectricity
EXTRACTION OF SANDS AND GRAVEL
Why are sands and gravels quarried
Construction materials - Roads, concrete blocks, pipes…
Water filtration
Glass making
Icy roads in winter
EXTRACTION OF SANDS AND GRAVEL
Where in Shropshire is being quarried
Wood Lane, Ellesmere, Shropshire
EXTRACTION OF SANDS AND GRAVEL
What are the negatives of quarrying
Destroys environment and habitats, long term and short term
Destroys breeding ground for 180 species of birds
HGVs travel on small rural roads - road accidents and noise
EXTRACTION OF SANDS AND GRAVEL
What are the positives of quarrying
Reduces reliance on imports from abroad
250,000 tons of material over 8 years.
Provides low-skill jobs
DEGRADATION OF PERMAFROST
What human activities cause the melting of permafrost?
Buildings and infrastructure - heating
Roads - friction from wheels, removal of vegetation, dark surfaces
DEGRADATION OF PERMAFROST
What are two impacts of melting of permafrost
Subside of buildings - movement of foundations
Damage to infrastructure - Costing $35million per year in Alaska
OIL EXTRACTION AND TRANSPORTATION
What is the Trans-Alaska pipeline. How much did it cost to construct?
Above-ground pipeline that transports oil across Alaska.
Cost $8 billion
DEGRADATION OF PERMAFROST
What is two problems that was faced during the construction of the Trans-Alaska pipeline. How was this overcame
Oil is warm, so would thaw the permafrost.
Pipeline is built up to 3m above ground.
Natural disasters
Pipeline is built with sleepers that allow for movement
What is anthropogenic climate change
Climate change caused by human factors
What is artic amplification
Artic warms 2x as fast, due to climate change, as the rest of the world
Why is Permafrost a carbon sink
Methane is contained within, due to the anaerobic respiration of decomposers
