Current Science: Recent climate changes have had significant impact on high-mountain glacial environment. Rapid melting of snow/ice and heavy rainfall has resulted in the formation and expansion of moraine-dammed lakes, creating a potential danger from dammed lake outburst floods1. On 16 and 17 June 2013, heavy rains together with moraine dammed lake (Chorabari Lake) burst caused flooding of Saraswati and Mandakini Rivers in Rudraprayag district of Uttarakhand (Figure 1a).
Prolonged heavy down pour on 16 and 17 June 2013 resembled ‘cloud burst’(except for amount of precipitation of 100mm/h) type event in the Kedarnath valley and surrounding areas that damaged the banks of River Mandakini for 18km between Kedarnath and Sonprayag, and completely washed away Gaurikund (1990masl), Rambara (2740masl) and Kedarnath (3546masl) towns. The roads and footpath between Gaurikund and Kedarnath were also damaged.
There are reports of loss of large number of human lives and damage to the property and livestock. The Chorabari Lake(3960masl) also known as Gandhi Sarovar Lake, is a snow melt and rain fed lake, located about 2km upstream of Kedarnath town which is approximately 400m long, 200m wide having a depth of 15–20m. The bursting of this lake led to its complete draining within 5–10min as reported by the watch and ward staff of the Wadia Institute of Himalayan Geology (WIHG), who were present in WIHG camp at Chorabari Glacier on 16 June and early morning of 17 June 2013. The heavy rainfall together with melting of snow in the surrounding Chorabari Lake washed off both the banks of the Mandakini River causing massive devastation to the Kedarnath town.
The WIHG meteorological observatory at Chorabari Glacier camp (3820masl) recorded 210mm rainfall in 12 hours between 15 June (5:00 p.m.) and 16 June (5:00a.m.) 2013. On 16 June 2013 alone from 5:00a.m.to 5:00p.m.), 115 mm rainfall was recorded, causing 325 mm rain in 24 hours. The WIHG has another rain gauge installed at its geophysical facility (MPGO) at Kopardhar near Ghuttu (30.53N, 78.74E; 1836masl),which is approximately 38km (aerial distance) from Kedarnath. The Ghuttu rain gauge recorded 58mm on 15 June, 121mm on 16 June and 93mm on 17 June with no rainfall on 18 June (Figure 2).
The surface atmospheric pressure began to decrease on 15 June reaching a low (832.4mB) on 17 June (Figure 2). During 15–17 June 2013, the heavy rains also caused devastation in other regions of Uttarakhand, Himachal and Nepal.
Figure 1. a, Satellite view of Kedarnath area, showing drainage system, glaciers, lake and township4; b, The India Meterological Department image (17 June 2013) suggested that the heavy rainfall on the higher Uttarakhand, Himachal and Nepal Himalaya caused the collision of the monsoon and westerly disturbance. Arrows (red colour) on the map indicate the moisture sources of the area. (Source: Figure 1 b: http://www.imd.gov.in/section/satmet/dynamic/insat.htm)
The India Meteorological Department (IMD) linked heavy to very heavy rain-fall on the higher Uttarakhand, Himachal and Nepal Himalaya to the convergence of the Southwest Monsoon trough and (5:00 p.m.) and 16 June (5:00a.m.) 2013.
The India Meteorological Department (IMD) linked heavy to very heavy rain-fall on the higher Uttarakhand, Himachal and Nepal Himalaya to the convergence of the Southwest Monsoon trough and westerly disturbances, which led to the formation of dense cloud over the Uttarakhand Himalaya (Figure 1 b).
Figure 2. Rainfall and atmospheric pressure recorded at Kopardhar observatory near Ghuttu (WIHG), which is approximately 38 km (aerial distance) from Kedarnath.
The Kedarnath temple town is located in the western extremity of the Central Himalaya (30446.7N; 79041E) in the Mandakini River valley which has a total catchment area of ~67 km2 (up to Rambara), out of which 23% area is covered by glaciers2. The catchment area is situated in the glacier modified U-shaped valley; the altitude ranges from 2740 to 6578 masl. Such a variation in the altitude provides diverse landscape.
Bhart Khunta (6578 m), Kedarnath (6940 m), Mahalaya peak (5970 m) and Hanuman top (5320 m) are few well known peaks in the area. Mandakini River originates from the Chorabari Glacier (3895 m) near Chorabari Lake (Figures 1 and 3) and joins Saraswati River which originates from Companion glacier at Kedarnath (Figure 3), passing through Rambara and Gaurikund. The Madhu Ganga and Dudh Ganga are the main tributaries that merge into the Mandakini River at Kedarnath town. Another equally important tributary of Mandakini River is Son Ganga which originates from Vasuki Lake (4040 masl) and has a confluence with Mandakini River at Sonprayag (1709 masl) which finally merges with Alaknanda River at Rudraprayag.
Geologically, the area north of the Pindari Thrust comprises calc-silicate, biotite gneisses, schist and granite pegmatite apatite veins belonging to the PindariFormation3. Above 3800masl altitudes, glacial processes dominate and between3800 and 2800 masl glaciofluvial processes are dominant; below 2800 masl mainly the fluvial processes are active. Geomorphologically, Mandakini valley was formed by the erosional and deposional processes of glaciofluvial origin. The Kedarnath town is situated on the out wash plane of Chorabari and Companion glaciers (Figure 3). The channels of Mandakini and Saraswati Rivers encircles this outwash plane and meet near the Kedarnath town where the outwash plane ends. These streams cut their banks every year. Overcrowding of the people near the temple led to a change in the course of Sarswati River which now flows just behind the Kedarnath town (Figure 3).
Figure 3. Geomorphological setup of the Kedarnath area and view of settlement of the Kedar-nath town along the river bank of Mandakini (May 2012 photo).
Downstream near Rambara and Gaurikund the houses have been built on the old colluvial or fluvial deposits which are loose and prone to landslides and river cuttings.
Rainfall data from an automatic weather station (installed near the Chorabari snout) indicates that the Indian Summer Monsoon is the major source of precipitation (rainfall) in the study area with partial contribution from western disturbances during winter. Winter precipitation generally occurs between December and March when the western disturbances are dominant in the area as they move eastward over northern India. Total summer (JJAS) rainfall for each observation periods between 2007 and 2012 were 1685mm, 1513mm, 734mm, 1662mm, 1348mm and 1115mm for respective years. Based on the available rainfall data from our observatory at Chorabari glacier, the area received maximum precipitation during the rainy season, i.e. July and August(Figure 4).
Figure 4. Histogram of summer rainfall pattern of the Kedarnath area during the period 2007 to 2012 AD. Maximum precipitation occurred during the rainy season from July and August5.
The preliminary results suggest that the following two events caused devastation in the Kedarnath area of the Mandakini River basin
Figure 5. a, The Landsat (8) satellite image (23 June 2013; after disaster), sowing the, lake burst (1), Gulleys erosion/cloud burst events (2) and circle (3) indicate the site of maximum devastation (http://blogs.agu.org/landslideblog/). b, The panoramic view of Chorabari Lake and Gla-cier, the red circle indicate the weak zone of the lake, where the lake was burst. c, The photograph showing the maximum devastation in Kedar-nath town (Photo: Internet). d, Cartosat image (Bhuwan) of post disaster of the Kedarnath and surrounding areas and clearly indicating Chorabari Lake outburst. The red circle indicates the breaching point of the Lake (http://bhuvan-noeda.nrsc.gov.in/projects/flood/#mappage).
On 16 June2013, at 5:15p.m., the torrential rains flooded the Saraswati River and Dudh Ganga catchment area, resulting in excessive flow across all the channels. Following this very active erosion began in all the other gulleys causing excessive water and sediment accumulation in the major rivers (Figure 5a). As a result, large volumes of water struck the town which simultaneously picked huge amount of loose sediment enroute. The voluminous water studded with debris from the surrounding regions and glacial moraines moved towards Kedarnath town, washing off upper part of the city (Sankaracharya samadhi, Jalnigam guest house, Bharat Seva Sangh Ashram,etc.) and leading to the biggest ever devastation we have seen in the region. Our meteorological stations near Chorabari glacier recorded 325mm rainfall at the base of the glaciers in two days on 15 and 16 June 2013. Due to heavy downpour, the town of Rambara was completely washed away on 16 June evening.
The second event occurred on 17 June2013 at 6:45a.m., after overflow and collapse of the moraine dammed Chorabari Lake (Figure 5a and b) which released large volume of water that caused another lash flood in the Kedarnath town leading to heavy devastation downstream (Gaurikund, Sonprayag, Phata, etc.).
Our study shows that the main cause of the Chorabari Lake collapse was torrential rains that the area received between 15 and 17 June 2013. Due to heavy rainfall the right lateral basin of the glacier, which is thickly covered by snow (>7 feet thick near the upper part of lake during field work on 4 June 2013) rapidly melted due to rain-water allowing large amount of water accumulation in the Gandhi Sarovar lake (Figure 5b). There were no outlets in the lake, the water was simply released through narrow passage sat the bottom of the lake. Suddenly millions of gallons of water accumulated in the moraine dammed lake within 3 days, which increased their potential energy and reduced the shear strength of the dam. Ultimately the loose-moraine dam breached causing an enormous devastation in the Kedarnath valley (Figure 5a).
Recently, the risk of natural disasters has increased in the area as a result of increasing anthropogenic activities(Figure 3). This trend is likely to increase in future as the activities like pilgrimage, tourism, etc. will increase. The natural flow paths of the channels get obstructed due to the construction of man-made structures that results in deviation of the flow from its natural course.
Apprehending the tendency of increasing urbanization due to increase in the number of pilgrims, tourists and other developmental activities in the area, selection of safe land-use locations would be a formidable task to accomplish. However, the Government has to take care of these issues in future rebuilding of the devastated area, though the task of rehabilitation of the displaced population is enormous.
- Bajracharya, S. R. and Mool, P.,Ann.Gla-ciol.,2009,50, 81–86.
- Mehta, M., Majeed, Z., Dobhal, D.P. and Srivastava, P., J. Earth Syst. Sci., 2012, 121, 149–163.
- Valdiya, K.S., Paul, S.K., Chandra, T., Bhakuni, S. S. and Upadhyaya, R.C., Himalayan Geol., 1999, 20, 117.
- Bhambri, R., Bolch,T.,Chaujar, R. K.and Kulshreshta, S. C.,J.Glaciol., 2011,57, 543–556.5.Dobhal, D.P., Mehta, M. and Srivastava,D., J.Glaciol.,2013 (in press).
Authors: D.P.DOBHAL*ANIL K.GUPTAMANISH MEHTA D.D.KHANDELWAL Wadia Institute of Himalayan Geology, Dehradun 248 001, India *For correspondence. email: firstname.lastname@example.org
Published in CURRENT SCIENCE, VOL. 105, NO. 2, 25 JULY 2013
Climate Himalaya’s Take: There are a few burning issues on ‘Kedarnath’ disasters and they are about the ‘early warning’ of the event, the habitation and the kind of scientific arguments and public opinion is floating around.
The first and foremost point is that, when Wadia Institute of Himalayan Geology (WIHG), that is based in the capital of Uttarakhand state of India, had the observatories at two places; near Chorabari lake (above Kedarnath in Uttarakhand) and Kopardhar (Ghuttu, in Tehri, Uttarakhand), recording heavy rainfall starting from 10th June 2013, why not WIHG informed about such occurrence uneven event in pre-monsoon period?
Also, other reliable rainfall data sets show that the uneven and unpredicted heavy rainfall in this region started since 7th June 2013, and it remained till 17th June, by the time the disaster led to heavy toll in many parts of Uttarakhand. Scientists those have papers in press now, and are working in premier institutions, have suggested that the rainfall and weather change analysis should have been done based on a longer period of rainfall i.e. between 7-17 June, and a thorough analysis should have given a clear picture from previous 50-60 years of variability in rainfall and temperature patterns.
The analysis based on 7 days, 10 days, one months and yearly rainfall pattern across the North Western Himalayan mountain region shows that in the last 1000 years this event is unique and didn’t happen, and may not repeat again so easily. So, it was one of the rarest of the rare event on geological timescale in the Himalayan region.
This paper also talks about increase in risks of natural disaster in the area as a result of increasing anthropogenic activities and likely increase in such trend from pilgrimage and tourism. It also talks about obstruction of natural flow path channel due to man made structure leading to deviation in flow path.
Does it mean that the phenomena was driven by localized anthropogenic activities with in Kedarnath area where the breach of lake led to devastation? Or it could be termed as a cumulative phenomena of change in temperature and precipitation that was very much driven by various global phenomena of mixed natural and anthropogenic causes? The paper has no facts this part!
Also, an area and for that matter the Kedarnath township, that exists historically for thousands of years, WIHG report finds that planned construction could have avoided the disaster! Does this argument substantiate the level and intensity of the flood that hit the Kedarnath township during 16 and 17 June 2013!
The fact of the matter is that, the Kedarnath township itself is located at a much higher plateau to the original course of Mandakini river, and such event was beyond expectations or control of human being. We must need to also consider about the status of non-affected or impacted houses, and they are over 60 percent of total numbers. These houses were constructed way back by locals inhabitants, considering land type, material use and construction technology, and they survived and are still in safer places.
The death tolls in these houses were much less than what has been reported by many non-scientific agencies and media.
The major reason, we find for huge death toll was related to no ‘early warning’ by agencies and authorities with the start of pouring of rain from 14th June, while in this region all satellite phones and mobile towers were working perfectly. Any cautious warning could have reduced the numbers of death tolls and people could have taken shelter in higher places as many local inhabitants and alert tourists did starting from 16th evening.
Also, the phenomena of Kedarnath disaster is clearly linked with the disintegration of glacial mass in Chorabari glacier for a long time, increased temperature during that particular month in Kedarnath area and the heavy rainfall together. Even if the phenomena of high movement or uneven movement in the glacial mass was reported timely as an early warning, it could have avoided the huge death toll, but, it didn’t happen.
The buck was ultimately shifted to wrong construction, while scientists failed to report the possible occurrence of such incidence in the region and administration in relief, rescue and rehabilitation.
Comments on this post in Other social forums
Florin Florin I. Vice President at Romanian Water Association
I think that the proffesional peoples working with water in different ways have to share their experience and lessons learnt from different situations from daily work in order to understand all of us climate changes facts and causes and to prevent if possible.The subject is important for all of us and I hope that a relay exchange of ideas and information should be useful to improve water management everywhere in the world.The attached article is important and offers a lot of explanations regarding the disaster happened in Kedarnath.
K R T, K R T A. Consultant – Water & Water Resources
I wonder if there is there a separate mathematical tool to predict and analyses flash floods? This is critical and important in the Himalayan region and the region downstream to prevent future disasters. While I feel we are improving with respect to the prediction of rainfall and more so of Monsoons in our country, the Himalayan Hydrologists should come together to solve the disasters the flash floods in the region.
Prof. Partha Sarathi, Prof. Partha Sarathi D. Experienced Adviser and Consultant on Water & Environment; Water & Energy Security; Climate; Sustainable Development.
I agree with the views of Florin. Limited knowledge on the heterogeneity in land-form changes and geological formation causes threat from natural hazards induced disasters to the population. In absence of hazard resilient coherent long-term management policies, disasters result due to human failure to introduce proper preparedness measures, and tendency to manage vulnerability and risks by ad hoc and tactical approaches. The Geoscientists, Meteorologists and Hydrologists working on Himalayan Region have a significant role to play to combat such disaster.
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