Uttarakhand Floods 2013
In June 2013, the hills of Uttarakhand were subjected to unusual intense rainfall (370 Millimetres recorded at Dehradun). Instances of such extreme precipitation of 370 millimetres or more have been witnessed in July, August and September and also in January, April and May, but never in June. It was the high amount of rainfall that created havoc in the state. This heavy rainfall was not confined to the Mandakini Valley of the Uttarakhand but also a large region of western and central Himalayas. There were high floods in Nepal also, but not much loss of life was there due to early warning system.
Location of Kedarnath
The Kedarnath temple is situated in the Mandakini valley below the Chorabari glacier. Chorabari Glacier is the source of the Mandakini. The altitude of Kedarnath is 3590 metres above sea level. The altitude of Gandhi sarovar or Chorabari taal is 3900 metres above sea level. Chorabari is a compound valley glacier having a total catchment area of 67 square kilometres (up to Rambara). Hill slopes upstream of Kedarnath are devoid of vegetation.
How the Disaster Happened?
It is still not completely clear what actually happened in the Mandakini valley upstream of Kedarnath which generated so much of water and debris flow over a short time. Google Earth imagery of this area was taken in winter so the whole area is covered by snow so it was not of much help. Some images available from the Indian CARTOSAT satellite available on the Bhuvan show a number of streams approaching Kedarnath town. Possible reasons for the disaster include a Glacial Lake Outburst Flood (GLOF) due to the failure of Chorabari Taal. The Chorabari Taal is approximately 800 metres long and 200 metres wide, situated upstream of Kedarnath and a catastrophic landslide in the upper region. As a result of failure of this lake, large volumes of water reached the town, having picked up huge amounts of loose sediment en route. The heavy and unprecedented rainfall triggered a collapse event on the mountain, which turned into a debris flow downstream.
According to a report based on high resolution satellite data collected using the RISAT-1 and available on Internet, the debris flow from northwest was initiated by a landslide high on the hillside, which then ran down the slope entraining debris en route. At the slope toe it was channelized by the glacier into a narrow gully. The flow eroded out a large amount of material in this gully. The area down slope of the failure was already a zone of active erosion, so the likelihood of carrying along of particles in a current was very high.
Kedarnath was struck by an earlier flow from the northeast, then a later flow from the northwest.
Was there any failure of dam?
Some people are of the opinion that the Kedarnath disaster was caused due to construction of hydropower projects in the Upper Ganga basin. However, the project nearest to Kedarnath is about 10 kilometres downstream and is under construction. Obviously, hydropower projects had no direct role in the catastrophic event.
Was it a manmade Disaster?
Excessive rainfall and Glacial Lake Outburst Flood provides only a partial explanation for why Kedarnath was battered beyond measure. The extreme and unseasonable rainfall that created havoc indicates us a global warming-induced climate change phenomenon. Warmer air due to global warming has the capacity to hold more moisture, leading to more intense bursts of rainfall. The natural monsoon cycle in India has already been badly disrupted, and a new cycle of extreme rainfall events and prolonged droughts has been reported from all over the country in the recent past. Thus, Uttarakhand disaster is not all natural and it is no less man-made than the other contributors to the tragedy.
Uttarakhand Floods and the Chaotic Development
Man’s excesses and follies have also been a factor in the destruction that nature has wrought. It is evident that the problem of poor soil stability on the steep slopes in this fragile region has been compounded by man-made factors such as indiscriminate deforestation and mindless construction. In Uttarakhand, a chaotic process of “development” that goes back many years exacerbated the effects of this extreme rain. Extensive deforestation of mountain tracts by the state and more recently due to “development” projects led to soil erosion and water run-off, thus destabilising mountain slopes and contributing to more intense and frequent landslides and floods. Unchecked hill tourism has resulted in the huge growth of vehicular traffic, spread of roads not suitable to this mountainous terrain, and the construction of poorly designed and unregulated hotels and structures, many near rivers. Sand mining along river banks has intensified water flows into rivers. Most of all, the construction and planning of hundreds of small, medium and large dams across the Himalayan states, from Himachal Pradesh and Uttarakhand in the northern Himalayas to Sikkim and Arunachal Pradesh in the east, have destabilised an already fragile ecosystem and threatened biodiversity.