On 7th February 2021 Uttrakhand was hit with nature’s fury once again when massive flooding happened in parts of Chamoli district. It has not been long when the flash floods in 2013 had ravaged the state.
The reason this time is being attributed to a glacial outburst from Nanda Devi glacier. It is termed as Glacial Lake Outburst Flood. What is Glacial Lake Outburst Flood? There are 1,000 glaciers in Uttarakhand and most of them are retreating. Retreating glaciers result in formation of lakes at their tips which are bound by sediments and boulders only. If something very heavy falls with a lot of force in these lakes, their boundaries can be breached and huge amounts of water can go rushing down to near by streams and water bodies. This is called as glacial lake outburst flood(GLOFs). In this case, it is being believed that an avalanche might have caused the lake to rupture its boundary and large amount of water came gushing down in nearby rivers of Rishiganga and Dhauli Ganga, causing flash floods.
GLOFs can have following features:
1) The release of water can happen suddenly.
2) There is large magnitude of water discharge downstream.
3) They tend to be rapid events which can last even for days.
4) The consequences can be disastrous. In this case around 35 lives are lost and more than 150 people are missing.
The exact reason for the disaster is yet to be ascertained. Satellite and Google Earth images do not show a glacial lake near the region but there is a possibility that there might have been a water pocket (lakes inside glaciers) in the region that may have erupted to cause this event.
This has brought 2 things in limelight again:
A) Nanda Devi glacial melt is being attributed to global warming. UN Intergovernmental Panel on Climate Change says glacial retreat and permafrost thaw (when ice inside the permafrost melts) decrease the stability of mountain slopes and increase the number and area of glacial lakes. The number of glacier lakes will continue to increase and such lake outbursts also might get easily triggered, if not taken care of.Some urgent intervention is seriously needed to avoid these incidents in future.
B) There are eight hydropower projects coming up in Uttarakhand. This state is a part of lesser Himalayas and experiences deep movement of rock assemblages and has been found tectonically active in recent times. The result is- geological stresses and weakening of rocks which makes development of large dams in the region imprudent.The net benefits of big dams are coming under question due to the collateral and immeasurable damage being caused to lives, livelihood and ecology. In recent tragedy, 2 hydropower projects(Rishiganga and Tapovan Vishnugad hydropower projects) bore the brunt. Rather, small low-impact dams can be an alternative.
Living W/ Creator 