Flash Flood in Uttarakhand
More than 150 people have been swept away by flash flood due to sudden rise in water level in Dhauli Ganga and Alaknanda River due to the breakdown of a glacier in Tapovan-Raini area of Chamoli district of Uttarakhand. All these people were working in the Rishi Ganga Power Project. This has caused significant damage to the Rishiganga power project also.
What is Glacier Burst?
- For years, glaciers are formed by the freezing and gathering of ice at one place.
- 99 percent of the glaciers are in the form of ice sheets. It is also called continental glacier.
- These are the largest freshwater basins that cover about 10% of the Earth’s land.
- This occurs mostly in Polar region or hilly areas of very high altitude. Similar glaciers are also found in the Himalayan regions.
- It breaks when there is activity under it due to a geological movement. At times, due to global warming, glacial ice also melts and breaks into large pieces. This process is called glacier bursting or breakage.
Type of Glaciers:
These are of two types: first, alpine glaciers and second, ice sheets. Mountain glacier comes under the Alpine range.
Flash flood :
- This phenomenon refers to the sudden increase in water level during or after the rains.
- This phenomenon can be caused by heavy rain, hurricanes, tropical storms, melting of snow, etc.
- The occurrence of flash floods can also be caused by dam breakdown and/or debris flow.
- It is a phenomenon that occurs in very short periods of time at very high places, usually with a difference of less than six hours between rainfall and floods.
- Flash floods become terrible due to poor drainage systems or encroachments that obstruct the natural flow of water.
- Volcanic eruptions are also responsible for flash floods, because after the volcanic eruption there is a rapid rise in the temperature of the surroundings, to melt the glaciers present in these regions.
- The nature of flash flood determines by all the intensity of rainfall, distribution of rainfall, type of land use and topography, vegetation type and growth /density, soil type, etc.
The retreat of glaciers in the Himalayas forms lakes, which is called the Proglacial lakes, which is bound by sediment and large stones.
Source: Indian Express