Glaciers Shrinking in Nepal Himalaya

Abstract

Glaciers are repositories of information for climate change studies, as they are sensitive to global temperature and precipitation changes. Due to global warming the impact was directly influencing in the melting of the glaciers and enhancing in recent decades. The rapid melting of glaciers reduce the glacier area by which the glaciers are fragmented with increase in glacier number (Bajracharya et al., 2006a,b, 2007a,b, 2008, 2009a). The history of glacier study in Nepal is not old, it was just started by Fritz Műller in 1956; who visit Nepal as a participant in the Swiss Everest Expedition. During following years, the number of scientific expeditions has gradually increased. However, Nepal has no glaciers under longterm observation, though a number of fragmented and short studies have been made on the AX010 Glacier, Mera Glacier, Yala Glacier and Rikha Samba Glacier. The AX010 has the densest observations in terms of Glacier extent, mass balance, and ice flow (Fujita et al., 2001). The systematic investigation of glaciers in Nepal was first organized by Nagoya and Kyoto Universities of Japan. The Glaciological Expedition of Nepal (GEN), led by Higuchi (1976, 1977, 1978, 1980), carried out a series of field studies in coordination with Department of Hydrology and Meteorology (DHM) Nepal. The first detailed study of AX010 glacier was conducted in 1978/1979 (Ageta et al., 1980, 1992; Kadota et al., 1997), Yala Glacier was studied since the 1980s, and Rikha Samba Glacier has been surveyed intermittently since 1974 (Nakawo et al., 1976; Fugii et al., 1996; Fugita et al., 1997). The glaciers of Nepal was first mapped by ICIMOD in 2001 from the Indian Survey topographic maps published from 1963 to 1982. The maps were prepared from the aerial photographs of 1957 to 1959 with extensive field work (Mool et al.; 2001, 2005). The study revealed 3,252 glaciers with 5,323km2 glacier area, which is almost 3.6% of the total land cover of Nepal. The second generation of glacier mapping of Nepal (Bajracharya et al., 2011 unpub.) was based on the satellite images of 2008/2009, which shows that the number of glacier has apparently increased but the total area has decreased drastically. The total number of glaciers in this survey shows 3808 glaciers with 4212km2 glacier area and 346km3 estimated ice reserves. The glacier area loss is about 20% in last 40 years. The glacier cover of Nepal reduces to 2.9% of total land cover in Nepal. The subsidence of glacier surface by 0.40m per year in Dudh Koshi basin is also reported since late 1960's due to the melting of the glaciers (Bolch, 2008). Bajracharya et al., 2008 has also reported the glacier retreat rate of 10 to 60m per year in Dudh Koshi basin. GEN, 2006 has studied many glaciers and reported the glacier retreat