Hydro Projects on Himalayas pose threat of floods: Analysis
Potential hydro power projects in the Himalayan region would need to factor in chances of increased floods from the formation of new lakes and the expansion of existing ones due to melting glaciers, says an analysis of Himalayan glaciers and their possible future impact on livelihoods in States adjoining the region. The results are part of a modelling study by Swiss researchers on the impact of climate change in the Himalayas.
According to the study, 441 hydro-power projects spanning India, Nepal, Pakistan and China, that is, 66% of constructed and potential hydro power projects, are on possible Glacier Lake Outburst Floods (GLOF) tracks, which means they could be gorged with extra water from melting glaciers.
Almost a third of these hydro power projects could experience GLOF discharges well above what these dams account for, says a study.
What is GLOF?
A glacial lake outburst flood (GLOF) is a type of outburst flood that occurs when the dam containing a glacial lake fails. Failure can happen due to erosion, a build-up of water pressure, an avalanche of rock or heavy snow, an earthquake , volcanic eruptions under the ice, or if a large enough portion of a glacier breaks off and massively displaces the waters in a glacial lake at its base.
India accounts for 129 of the hydro projects analysed. India’s environment and water resources ministries are engaged in a tiff with the power ministry over the construction of forthcoming hydro power projects in Uttarakhand.
Broadly, they deal with the impact of these projects on the local ecology and on the natural flows of the rivers they are built upon.
There was a paucity of data regarding the health of Himalayan glaciers, and depending on their location within the Himalayan range, there were varying rates of glacial melt.
Findings of the study:
The findings come even as researchers note that global warming could cause glaciers to melt rapidly, which is already evident in an increase in the number of glacier-fed lakes in Himachal.
In the Beas basin, six lakes in 1989 had increased to 33 in 2011, and in the Parvati Valley catchment area, there was an increase from 12 lakes (in 1989) to 77 lakes (in 2014). Most of the Himachal Pradesh lakes were relatively small or with a capacity of a million cubic metres, and only a few of them had a capacity larger than 10 million cubic metres of water.