The region of the Uttarakhand state in India witnessed a major tragedy due to flash floods that occurred on account of glacial fields melting during the monsoons. A glacial break in the Tapovan-Reni area of Chamoli District of Uttarakhand led to massive Flash Flood in Dhauli Ganga and Alaknanda Rivers, damaging houses and the nearby Rishiganga power project.
Flash Flood in Uttarakhand occurred due to the fall of a portion of Nanda Devi glacier in Rishiganga river near Hill station of Pindari Glacier.
This caused the overflow of water which falls from the Nanda Devi glaciers at a higher altitude into other major rivers like Rishiganga and Dhauliganga leading to a number of flash floods in the state of Uttarakhand.
Flash floods are sudden and intense floods that develop in normally dry channels and basins. Flash floods may occur after a heavy rain or snowmelt, or when a storm abruptly drops a large amount of precipitation on an area that hasn't had much time to drain.
A flash flood is different from a regular river flood. It may develop in just a few minutes, gradually filling up the area where it occurs. They can happen in many different types of places, such as deserts, cities, and even out at sea.
The flood situation worsens in the presence of choked drainage lines or encroachments obstructing the natural flow of water.
Flash floods can occur due to many reasons, but it all starts with the same problem. When rain falls at a much faster rate than the ground can absorb it, that excess water has to go somewhere. If there are no rivers, streams or channels for it to flow into, then it piles up in small areas and causes flash flooding or an overflow of water.
Flash floods can also be caused by dam or levee breaks, and/or mudslides. They also occur when too much water quickly flows down a narrow valley following heavy rain.
In areas on or near volcanoes, flash floods have also occurred after eruptions, when glaciers have been melted by the intense heat; lava is a fluid-like material that can flow very quickly and devastate everything in its path if left unmanaged.
Flash Flooding or rapid runoff is a sudden flow in a watercourse or on a level area caused by heavy rainfall, rapid snowmelt, or by the failure of an artificial embankment. Flash flooding may occur when intense rainfall over a short period of time causes rivers to overflow their banks and flood. This can happen within just a few minutes rather than within the span of several days, as is typical with an ordinary flood.
The glaciers are a thick mass of ice moving under a heavyweight. This ice mound is formed in areas where an accumulation of snow goes beyond its ablation over many years.
The mass moves with the force of gravity due to its own insidious pressure causing cracks and crevices to form on the side, and the movement of ice within it.
They are generally seen in the snow-fields. This largest freshwater basin covers around 10% of the land surface of the Earth.
According to the topography and the location of the glacier, it can be categorized as Mountain Glacier (Alpine Glaciers) or Continental Glacier (Ice Sheets).
There are a few primary factors that decide the rate of glacier growth and its extensiveness. These factors are precipitation, temperature, and accumulation area.
