Future Sustainability Challenges in Hindu Kush-Himalaya - Impact of Global Changes on Mountains: Responses and Adaptation - page 246

Figure 10.15. Formation of glacial lakes and glacier lake outburst fl ood in Bhutan. Rocky
debris pile up forming moraines, acting as natural dams for lakes fi lled with melt water at
the terminus of glacier. Rising water levels and failing of moraines dams of glacial lakes can
create catastrophic glacial outburst fl oods. A partial collapse of the moraine at the southwest
corner along the edge of the Luggye Lake in 1994, released a glacial outburst fl ood killing 21
people and swept away livestock, crops and homes. These lakes were not exist in 1969, now
offi cials are concern about the Thorthormi Glacier Lake and the unstable moraine separating
it from Raphstreng Lake. An outburst fl ood from Thorthormi into Raphstreng could easily
cause the lower lake to overfl ow (Michott Scott NASA Earth Observatory, modifi ed version
adopted from UNEP 2012a).
What are the Implications?
Is Melting expected in decades to come?
A signifi cant time lag (several decades or longer for most mountain glaciers)
occurs between changing climatic conditions and the resulting change in
glaciers (Armstrong 2010). This could be because of temperature in the