Disaster looms large over Joshimath (जोशीमठ पर मंडरा रहे आपदा के बादल ) फिर भी नहीं सम्भले ! !
(उत्तराखंड के अपने भू वैज्ञानिकों का यह शोध पत्र अंतर्राष्ट्रीय विज्ञान पत्रिका, करंट साइंस के मई 2010 के अंक में छपा )
– M. P. S. BISHT
-PIYOOSH RAUTELA
Published in May 2010
The area around Kunwari Pass in Central Himalayas is the source of a number of streams that include Dhaknala, Karmanasa, Patalganga, Belakuchi, and Garurganga. The first is the tributary of Dhauliganga whereas the rest drain into Alaknanda. These streams are known for the devastation they have caused in the past, due to the flash floods that followed the blockade of these streams due to landslides.
Joshimath is situated in the middle slopes of the hill bound by Karmanasa and Dhaknala on the west and the east respectively, together with Dhauliganga and Alaknanda on the other sides. Apart from
Joshimath, a number of settlements are located in the lower and middle slopes that include Chami, Shelong, Khanoti Chatti, Animath, Vishnuprayag, Khan, Parsari, Ganeshpur, Sunil, Gaukah, Dadon, Regaon, Oucha, Auli, Kharori, Kuni, Paiyan, Khancha, Barhgaon, Paini, Vishnupuram, Marwari, Bilagarh, Mirag, Karchhigaon, Tugasi, Chamtoli, and Jharkula Chatti. The total population of these habitations is around 18,000. The altitude varies between 1440 and 3797 m above sea level, and the upper reaches of the hill have a gentle gradient and a thick cover of old slide material. During winter, the upper reaches experience appreciable snow and the groundwater recharge due to the same is responsible for keeping the springs and streams around the area perennial.
Being situated in close proximity of major tectonic discontinuities, Joshimath has been showing signs of distress due to the burgeoning anthropogenic pressure. The area reportedly shows signs of continuous ground subsidence and the same has been recorded earlier1,3,4. The Mishra Commission5 reported that Joshimath is situated on an old landslide zone and is sinking. The report recommended that heavy construction be banned in the area around Joshimath.
Despite being fully aware of the geological/environmental vulnerability of the area, a number of hydroelectric schemes have been sanctioned around Joshimath and Tapovan. The Vishnugad HE Project is one such scheme. The head race tunnel of the project traverses all through the geologically fragile area below Joshi-math. It is interesting to note that a private company was preferred by National Thermal Power Corporation (NTPC) over the Geological Survey of India, for undertaking geological investigations related to the project. These investigations failed to take cognizance of the earlier geological investigations carried out in the area and did nothing to establish the depth of overburden all through the tunnel alignment.
A tunnel boring machine (TBM) was employed for excavating the head race tunnel. On 24 December 2009, it punctured a water-bearing strata some 3 km inward the left bank of Alaknanda near Shelong village. The site was more than a kilometer below the surface, somewhere below Auli, according to the project authorities. The water discharge was reportedly between 700 and 800 liters per second. The aquifer discharge was about 60–70 million liters daily, enough to sustain 2–3 million people. Even after a month, the aquifer had not dried out.
What a waste of a scarce resource! A sudden outpouring of water from an aquifer will have multifarious impacts but it would be a little early to dwell upon the full implications of the same. The water draining out through the tunnel would result in the drying up of springs around. Habitations around Joshimath would face a shortage of drinking water during the summer season. It is important to note that depletion in spring discharge and untimely drying up of a few springs have already been reported. This sudden and large-scale dewatering of the strata has the potential of initiating ground subsidence in the region, thereby augmenting the problems of the masses living in the area. Reduced ground moisture regime would result in depleted biomass availability and crop produce that would adversely affect the life support strategy of the masses. It would also impact floral and faunal diversity.
Being the gateway to Badrinath and Hemkunt Sahib shrines, the population of Joshimath generally witnesses a mani-fold increase, and the local administration would be hard-pressed for making water available to the visitors as also the local residents.
It is too early to foresee the full long-term implications of this event but these are sure to be serious. This is a clear case of negligence on the part of the agency undertaking the exploration in this sensitive zone. It calls for stringent compliance with the preliminary investigations together with harsh punitive measures for the ones who fail to comply.
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- Heim, A. and Gansser, A., Mem. Soc. Helv.
Sci. Nat., 1939, 73, 1–246.
- Valdiya, K. S., J. Geol. Soc. India, 1979,
20, 145–157.
- Auden, J. B., Rec. Geol. Surv. India, 1935,
69(1), 123–167.
- Valdiya, K. S., Aspects of Tectonics, Focus
on South-Central Asia, Tata McGraw-Hill,
New Delhi, 1984, pp. 319.
- Mishra Commission, 1964, Report of the
Commission set up by the Government of
India vide letter No. 142/23-5/44/76 dated
08.04.1976.
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- P. S. BISHT
PIYOOSH RAUTELA*
H.N.B. Garhwal University,
Srinagar (Garhwal),
Disaster Mitigation and Management
Centre,
Uttarakhand Secretariat,
4 Subash Road,
Dehradun 248 001, India
*e-mail: piyooshrautela@gmail.co