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Himalayan Geology, Vol. 32
(2), 2011, pp. 159-167, Printed in India
Avalanche morphometry and hazard potential assessment in Laxman Ganga
catchment Garhwal Himalaya
MANISH MEHTA1*, D.P. DOBHAL1, M.P.S. BISHT2
1Wadia Institute of Himalayan Geology, Dehra Dun, India
2HNB Garhwal University Srinagar, Garhwal, India
*Email: msmehta@wihg.res.in
Abstract: The present study area (~195 km2) falls within Laxman Ganga
catchment, a tributary of the Alaknanda River basin of the Garhwal Himalaya.
It is an important pilgrimage site where more than 3 lakh people visit every
year. The area is characterized by highly glacierised rugged topography with
prominent high relief ridges and deep valleys. The region experiences many
snow/ice avalanches causing damages to the pilgrim route which in turn
results in loss of human lives and set back to economy. In this study detail
mapping of 58 avalanche sites and their morphometrical analysis have been
carried out. The study reveals that most of the avalanche sites are located
between altitudes 2500 m and 4700 m with surface slope >25 degree. The
avalanche paths vary from 600 m to 3000 m in length. About 11% of the total
catchment area (195km2) is under influence of avalanche activities. It is
observed that the frequency of avalanches is more in the southern slope as
compared to other slopes of the valley. The preliminary results suggest that
besides morphometric parameters (slope, length, width and area), local
climate and intensity of snowfall play a vital role in the development of
avalanches.
Keywords: Himalaya, avalanche, morphometry, slope, mapping.
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